add maze generator community example

Add support for setting an icon of a window

.travis.yml

@@ -1,34 +0,0 @@
-language: go
-# https://github.com/golang/go/issues/31293
-dist: xenial
-sudo: false
-addons:
-    apt:
-        packages:
-            - xorg-dev
-            - libx11-dev
-            - libxrandr-dev
-            - libxinerama-dev
-            - libxcursor-dev
-            - libxi-dev
-            - libopenal-dev
-            - libasound2-dev
-            - libgl1-mesa-dev
-
-services:
-    - xvfb
-
-env:
-    - GO111MODULE=on
-
-go:
-    - tip
-    - 1.12.x
-
-install:
-    - # Do nothing. This is needed to prevent the default install action
-      # "go get -t -v ./..." from happening here because we want it to happen
-      # inside script step.
-
-script:
-    - go test -v -race -mod=readonly ./...

CHANGELOG.md

@@ -1,63 +0,0 @@
-# Changelog
-All notable changes to this project will be documented in this file.
-
-The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
-and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
-
-## [Unreleased]
-- Add AnchorPos struct and functions #252
-- Add Clipboard Support
-- Fix SIGSEGV on text.NewAtlas if glyph absent 
-- Use slice for range in Drawer.Dirty(), to improve performance
-- GLTriangle's fragment shader is used when rendered by the Canvas.
-- Add MSAA support
-
-## [v0.10.0] 2020-08-22
-- Add AnchorPos struct and functions
-- Gamepad API added
-- Support setting an initial window position
-- Support hiding the window initially
-- Support creating maximized windows
-- Support waiting for events to reduce CPU load
-- Adding clipping rectangle support in GLTriangles
-
-## [v0.10.0-beta] 2020-05-10
-- Add `WindowConfig.TransparentFramebuffer` option to support window transparency onto the background
-- Fixed Line intersects failing on lines passing through (0, 0)
-
-## [v0.10.0-alpha] 2020-05-08
-- Upgrade to GLFW 3.3! :tada:
-  - Closes https://github.com/faiface/pixel/issues/137
-- Add support for glfw's DisableCursor
-  - Closes https://github.com/faiface/pixel/issues/213
-
-## [v0.9.0] - 2020-05-02
-- Added feature from https://github.com/faiface/pixel/pull/219
-  - Exposing Window.SwapBuffers so buffers can be swapped without polling input
-- Add more examples
-- Add position as out variable from vertex shader
-- Add experimental joystick support
-- Add mouse cursor operations
-- Add `Vec.Floor(…)` function
-- Add circle geometry
-- Fix `Matrix.Unproject(…)` for rotated matrix
-- Add 2D Line geometry
-- Add floating point round error correction
-- Performance improvements
-- Fix race condition in `NewGLTriangles(…)`
-- Add `TriangleData` benchmarks and improvements
-- Add zero rectangle variable for utility and consistency
-- Add support for Go Modules
-- Add `NoIconify` and `AlwaysOnTop` window hints
-
-
-## [v0.8.0] - 2018-10-10
-Changelog for this and older versions can be found on the corresponding [GitHub
-releases](https://github.com/faiface/pixel/releases).
-
-[Unreleased]: https://github.com/faiface/pixel/compare/v0.10.0...HEAD
-[v0.10.0]: https://github.com/faiface/pixel/compare/v0.10.0-beta...v0.10.0
-[v0.10.0-beta]: https://github.com/faiface/pixel/compare/v0.10.0-alpha...v0.10.0-beta
-[v0.10.0-alpha]: https://github.com/faiface/pixel/compare/v0.9.0...v0.10.0-alpha
-[v0.9.0]: https://github.com/faiface/pixel/compare/v0.8.0...v0.9.0
-[v0.8.0]: https://github.com/faiface/pixel/releases/tag/v0.8.0

CONTRIBUTING.md

@@ -1,16 +0,0 @@
-# Contributing to Pixel
-
-:tada: Hi! I'm really glad you're considering contributing to Pixel! :tada:
-
-## Here are a few ways you can contribute
-
-1. **Make a community example** and place it inside the `community` folder of the [examples repository][examples].
-2. **Add tests**. There only few tests in Pixel at the moment. Take a look at them and make some similar.
-3. **Add a small feature or an improvement**. Feel like some small feature is missing? Just make a PR. Be ready that I might reject it, though, if I don't find it particularly appealing.
-4. **Join the big development** by joining the discussion on our [Discord Server](https://discord.gg/q2DK4MP), where we can discuss bigger changes and implement them after that.
-
-## How to make a pull request
-
-Go gives you a nice surprise when attempting to make a PR on Github. The thing is, that when user _xyz_ forks Pixel on Github, it ends up in _github.com/xyz/pixel_, which fucks up your import paths. Here's how you deal with that: https://www.reddit.com/r/golang/comments/2jdcw1/how_do_you_deal_with_github_forking/.
-
-[examples]: https://github.com/faiface/pixel-examples/tree/master/community

README.md

@@ -1,12 +1,4 @@
-# \*\*\*\*\*NOTICE\*\*\*\*\* 
-
-This repo is not under active development anymore and has been archived. Continued development has been migrated to [Pixel2](https://github.com/gopxl/pixel). A big thank you to [faiface](https://github.com/faiface) for creating this awesome library and for all the hard work put into it. We encourage old and new users to check out the new repo and contribute to it.
-
-
-
-<p align="center"><img src="logo/LOGOTYPE-HORIZONTAL-BLUE.png"></p>
-
-# Pixel [![Build Status](https://travis-ci.org/faiface/pixel.svg?branch=master)](https://travis-ci.org/faiface/pixel) [![GoDoc](https://godoc.org/github.com/faiface/pixel?status.svg)](https://godoc.org/github.com/faiface/pixel) [![Go Report Card](https://goreportcard.com/badge/github.com/faiface/pixel)](https://goreportcard.com/report/github.com/faiface/pixel) [![Join the chat at https://gitter.im/pixellib/Lobby](https://badges.gitter.im/pixellib/Lobby.svg)](https://gitter.im/pixellib/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![Discord Chat](https://img.shields.io/discord/699679031603494954)](https://discord.gg/q2DK4MP)  
+# Pixel [![GoDoc](https://godoc.org/github.com/faiface/pixel?status.svg)](https://godoc.org/github.com/faiface/pixel) [![Go Report Card](https://goreportcard.com/badge/github.com/faiface/pixel)](https://goreportcard.com/report/github.com/faiface/pixel) [![Join the chat at https://gitter.im/pixellib/Lobby](https://badges.gitter.im/pixellib/Lobby.svg)](https://gitter.im/pixellib/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 A hand-crafted 2D game library in Go. Take a look into the [features](#features) to see what it can
 do.
@@ -15,18 +7,8 @@ do.
 go get github.com/faiface/pixel
 ```
 
-If you are using Modules (Go 1.11 or higher) and want a mutable copy of the source code:
-
-```
-git clone https://github.com/faiface/pixel # clone outside of $GOPATH
-cd pixel
-go install ./...
-```
-
 See [requirements](#requirements) for the list of libraries necessary for compilation.
 
-All significant changes are documented in [CHANGELOG.md](CHANGELOG.md).
-
 ## Tutorial
 
 The [Wiki of this repo](https://github.com/faiface/pixel/wiki) contains an extensive tutorial
@@ -39,33 +21,28 @@ covering several topics of Pixel. Here's the content of the tutorial parts so fa
 - [Drawing efficiently with Batch](https://github.com/faiface/pixel/wiki/Drawing-efficiently-with-Batch)
 - [Drawing shapes with IMDraw](https://github.com/faiface/pixel/wiki/Drawing-shapes-with-IMDraw)
 - [Typing text on the screen](https://github.com/faiface/pixel/wiki/Typing-text-on-the-screen)
-- [Using a custom fragment shader](https://github.com/faiface/pixel/wiki/Using-a-custom-fragment-shader)
 
-## [Examples](https://github.com/faiface/pixel-examples)
+## Examples
 
-The [examples](https://github.com/faiface/pixel-examples) repository contains a few
+The [examples](https://github.com/faiface/pixel/tree/master/examples) directory contains a few
 examples demonstrating Pixel's functionality.
 
 **To run an example**, navigate to it's directory, then `go run` the `main.go` file. For example:
 
 ```
-$ cd pixel-examples/platformer
+$ cd examples/platformer
 $ go run main.go
 ```
 
 Here are some screenshots from the examples!
 
-| [Lights](https://github.com/faiface/pixel-examples/blob/master/lights) | [Platformer](https://github.com/faiface/pixel-examples/blob/master/platformer) |
+| [Lights](examples/lights) | [Platformer](examples/platformer) |
 | --- | --- |
-| ![Lights](https://github.com/faiface/pixel-examples/blob/master/lights/screenshot.png) | ![Platformer](https://github.com/faiface/pixel-examples/blob/master/platformer/screenshot.png) |
+| ![Lights](examples/lights/screenshot.png) | ![Platformer](examples/platformer/screenshot.png) |
 
-| [Smoke](https://github.com/faiface/pixel-examples/blob/master/smoke) | [Typewriter](https://github.com/faiface/pixel-examples/blob/master/typewriter) |
+| [Smoke](examples/smoke) | [Typewriter](examples/typewriter) |
 | --- | --- |
-| ![Smoke](https://github.com/faiface/pixel-examples/blob/master/smoke/screenshot.png) | ![Typewriter](https://github.com/faiface/pixel-examples/blob/master/typewriter/screenshot.png) |
-
-| [Raycaster](https://github.com/faiface/pixel-examples/blob/master/community/raycaster) | [Gizmo](https://github.com/Lallassu/gizmo) |
-| --- | --- |
-| ![Raycaster](https://github.com/faiface/pixel-examples/blob/master/community/raycaster/screenshot.png) | ![Gizmo](https://github.com/Lallassu/gizmo/blob/master/preview.png) |
+| ![Smoke](examples/smoke/screenshot.png) | ![Typewriter](examples/typewriter/screenshot.png) |
 
 ## Features
 
@@ -79,7 +56,6 @@ Here's the list of the main features in Pixel. Although Pixel is still under hea
     lines, ...)
   - Optimized drawing with [Batch](https://github.com/faiface/pixel/wiki/Drawing-efficiently-with-Batch)
   - Text drawing with [text](https://godoc.org/github.com/faiface/pixel/text) package
-- Audio through a separate [Beep](https://github.com/faiface/beep) library.
 - Simple and convenient API
   - Drawing a sprite to a window is as simple as `sprite.Draw(window, matrix)`
   - Wanna know where the center of a window is? `window.Bounds().Center()`
@@ -111,48 +87,33 @@ Here's the list of the main features in Pixel. Although Pixel is still under hea
 - Small codebase, ~5K lines of code, including the backend [glhf](https://github.com/faiface/glhf)
   package
 
- ## Related repositories
-
- Here are some packages which use Pixel:
- - [TilePix](https://github.com/bcvery1/tilepix) Makes handling TMX files built with [Tiled](https://www.mapeditor.org/) trivially easy to work with using Pixel.
- - [spriteplus](https://github.com/cebarks/spriteplus) Basic `SpriteSheet` and `Animation` implementations
- - [PixelUI](https://github.com/dusk125/pixelui) Imgui-based GUIs for Pixel
- - [pixelutils](https://github.com/dusk125/pixelutils) Variety of game related utilities (sprite packer, id generator, ticker, sprite loader, voronoia diagrams)
-
 ## Missing features
 
 Pixel is in development and still missing few critical features. Here're the most critical ones.
 
-- ~~Audio~~
+- Audio
 - ~~Drawing text~~
 - Antialiasing (filtering is supported, though)
 - ~~Advanced window manipulation (cursor hiding, window icon, ...)~~
 - Better support for Hi-DPI displays
 - Mobile (and perhaps HTML5?) backend
-- ~~More advanced graphical effects (e.g. blur)~~ (solved with the addition of GLSL effects)
+- More advanced graphical effects (e.g. blur)
 - Tests and benchmarks
-- Vulkan support
 
 **Implementing these features will get us to the 1.0 release.** Contribute, so that it's as soon as
 possible!
 
 ## Requirements
 
-If you're using Windows and having trouble building Pixel, please check [this
-guide](https://github.com/faiface/pixel/wiki/Building-Pixel-on-Windows) on the
-[wiki](https://github.com/faiface/pixel/wiki).
-
 [PixelGL](https://godoc.org/github.com/faiface/pixel/pixelgl) backend uses OpenGL to render
 graphics. Because of that, OpenGL development libraries are needed for compilation. The dependencies
 are same as for [GLFW](https://github.com/go-gl/glfw).
 
-The OpenGL version used is **OpenGL 3.3**.
-
 - On macOS, you need Xcode or Command Line Tools for Xcode (`xcode-select --install`) for required
   headers and libraries.
 - On Ubuntu/Debian-like Linux distributions, you need `libgl1-mesa-dev` and `xorg-dev` packages.
 - On CentOS/Fedora-like Linux distributions, you need `libX11-devel libXcursor-devel libXrandr-devel
-  libXinerama-devel mesa-libGL-devel libXi-devel libXxf86vm-devel` packages.
+  libXinerama-devel mesa-libGL-devel libXi-devel` packages.
 - See [here](http://www.glfw.org/docs/latest/compile.html#compile_deps) for full details.
 
 **The combination of Go 1.8, macOS and latest XCode seems to be problematic** as mentioned in issue
@@ -161,8 +122,6 @@ The OpenGL version used is **OpenGL 3.3**.
 
 ## Contributing
 
-Join us in the [Discord Chat!](https://discord.gg/q2DK4MP)
-
 Pixel is in, let's say, mid-stage of development. Many of the important features are here, some are
 missing. That's why **contributions are very important and welcome!** All alone, I will be able to
 finish the library, but it'll take a lot of time. With your help, it'll take much less. I encourage
@@ -178,7 +137,12 @@ requests. It just means that I might not like your idea. Or that your pull reque
 rewriting. That's perfectly fine, don't let it put you off. In the end, we'll just end up with a
 better result.
 
-Take a look at [CONTRIBUTING.md](CONTRIBUTING.md) for further information.
+**Don't start working on a pull request before submiting an issue or commenting on one. Proposals
+also take the form of issues.**
+
+For any kind of discussion, feel free to use our
+[Gitter](https://gitter.im/pixellib/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+community.
 
 ## License
 

batch.go

@@ -26,7 +26,7 @@ var _ BasicTarget = (*Batch)(nil)
 //
 // Note, that if the container does not support TrianglesColor, color masking will not work.
 func NewBatch(container Triangles, pic Picture) *Batch {
-	b := &Batch{cont: Drawer{Triangles: container, Picture: pic, Cached: true}}
+	b := &Batch{cont: Drawer{Triangles: container, Picture: pic}}
 	b.SetMatrix(IM)
 	b.SetColorMask(Alpha(1))
 	return b

circle.go

@@ -1,334 +0,0 @@
-package pixel
-
-import (
-	"fmt"
-	"math"
-)
-
-// Circle is a 2D circle. It is defined by two properties:
-//  - Center vector
-//  - Radius float64
-type Circle struct {
-	Center Vec
-	Radius float64
-}
-
-// C returns a new Circle with the given radius and center coordinates.
-//
-// Note that a negative radius is valid.
-func C(center Vec, radius float64) Circle {
-	return Circle{
-		Center: center,
-		Radius: radius,
-	}
-}
-
-// String returns the string representation of the Circle.
-//
-//  c := pixel.C(10.1234, pixel.ZV)
-//  c.String()     // returns "Circle(10.12, Vec(0, 0))"
-//  fmt.Println(c) // Circle(10.12, Vec(0, 0))
-func (c Circle) String() string {
-	return fmt.Sprintf("Circle(%s, %.2f)", c.Center, c.Radius)
-}
-
-// Norm returns the Circle in normalized form - this sets the radius to its absolute value.
-//
-// c := pixel.C(-10, pixel.ZV)
-// c.Norm() // returns pixel.Circle{pixel.Vec{0, 0}, 10}
-func (c Circle) Norm() Circle {
-	return Circle{
-		Center: c.Center,
-		Radius: math.Abs(c.Radius),
-	}
-}
-
-// Area returns the area of the Circle.
-func (c Circle) Area() float64 {
-	return math.Pi * math.Pow(c.Radius, 2)
-}
-
-// Moved returns the Circle moved by the given vector delta.
-func (c Circle) Moved(delta Vec) Circle {
-	return Circle{
-		Center: c.Center.Add(delta),
-		Radius: c.Radius,
-	}
-}
-
-// Resized returns the Circle resized by the given delta.  The Circles center is use as the anchor.
-//
-// c := pixel.C(pixel.ZV, 10)
-// c.Resized(-5) // returns pixel.Circle{pixel.Vec{0, 0}, 5}
-// c.Resized(25) // returns pixel.Circle{pixel.Vec{0, 0}, 35}
-func (c Circle) Resized(radiusDelta float64) Circle {
-	return Circle{
-		Center: c.Center,
-		Radius: c.Radius + radiusDelta,
-	}
-}
-
-// Contains checks whether a vector `u` is contained within this Circle (including it's perimeter).
-func (c Circle) Contains(u Vec) bool {
-	toCenter := c.Center.To(u)
-	return c.Radius >= toCenter.Len()
-}
-
-// Formula returns the values of h and k, for the equation of the circle: (x-h)^2 + (y-k)^2 = r^2
-// where r is the radius of the circle.
-func (c Circle) Formula() (h, k float64) {
-	return c.Center.X, c.Center.Y
-}
-
-// maxCircle will return the larger circle based on the radius.
-func maxCircle(c, d Circle) Circle {
-	if c.Radius < d.Radius {
-		return d
-	}
-	return c
-}
-
-// minCircle will return the smaller circle based on the radius.
-func minCircle(c, d Circle) Circle {
-	if c.Radius < d.Radius {
-		return c
-	}
-	return d
-}
-
-// Union returns the minimal Circle which covers both `c` and `d`.
-func (c Circle) Union(d Circle) Circle {
-	biggerC := maxCircle(c.Norm(), d.Norm())
-	smallerC := minCircle(c.Norm(), d.Norm())
-
-	// Get distance between centers
-	dist := c.Center.To(d.Center).Len()
-
-	// If the bigger Circle encompasses the smaller one, we have the result
-	if dist+smallerC.Radius <= biggerC.Radius {
-		return biggerC
-	}
-
-	// Calculate radius for encompassing Circle
-	r := (dist + biggerC.Radius + smallerC.Radius) / 2
-
-	// Calculate center for encompassing Circle
-	theta := .5 + (biggerC.Radius-smallerC.Radius)/(2*dist)
-	center := Lerp(smallerC.Center, biggerC.Center, theta)
-
-	return Circle{
-		Center: center,
-		Radius: r,
-	}
-}
-
-// Intersect returns the maximal Circle which is covered by both `c` and `d`.
-//
-// If `c` and `d` don't overlap, this function returns a zero-sized circle at the centerpoint between the two Circle's
-// centers.
-func (c Circle) Intersect(d Circle) Circle {
-	// Check if one of the circles encompasses the other; if so, return that one
-	biggerC := maxCircle(c.Norm(), d.Norm())
-	smallerC := minCircle(c.Norm(), d.Norm())
-
-	if biggerC.Radius >= biggerC.Center.To(smallerC.Center).Len()+smallerC.Radius {
-		return biggerC
-	}
-
-	// Calculate the midpoint between the two radii
-	// Distance between centers
-	dist := c.Center.To(d.Center).Len()
-	// Difference between radii
-	diff := dist - (c.Radius + d.Radius)
-	// Distance from c.Center to the weighted midpoint
-	distToMidpoint := c.Radius + 0.5*diff
-	// Weighted midpoint
-	center := Lerp(c.Center, d.Center, distToMidpoint/dist)
-
-	// No need to calculate radius if the circles do not overlap
-	if c.Center.To(d.Center).Len() >= c.Radius+d.Radius {
-		return C(center, 0)
-	}
-
-	radius := c.Center.To(d.Center).Len() - (c.Radius + d.Radius)
-
-	return Circle{
-		Center: center,
-		Radius: math.Abs(radius),
-	}
-}
-
-// IntersectLine will return the shortest Vec such that if the Circle is moved by the Vec returned, the Line and Rect no
-// longer intersect.
-func (c Circle) IntersectLine(l Line) Vec {
-	return l.IntersectCircle(c).Scaled(-1)
-}
-
-// IntersectRect returns a minimal required Vector, such that moving the circle by that vector would stop the Circle
-// and the Rect intersecting.  This function returns a zero-vector if the Circle and Rect do not overlap, and if only
-// the perimeters touch.
-//
-// This function will return a non-zero vector if:
-//  - The Rect contains the Circle, partially or fully
-//  - The Circle contains the Rect, partially of fully
-func (c Circle) IntersectRect(r Rect) Vec {
-	// Checks if the c.Center is not in the diagonal quadrants of the rectangle
-	if (r.Min.X <= c.Center.X && c.Center.X <= r.Max.X) || (r.Min.Y <= c.Center.Y && c.Center.Y <= r.Max.Y) {
-		// 'grow' the Rect by c.Radius in each orthagonal
-		grown := Rect{Min: r.Min.Sub(V(c.Radius, c.Radius)), Max: r.Max.Add(V(c.Radius, c.Radius))}
-		if !grown.Contains(c.Center) {
-			// c.Center not close enough to overlap, return zero-vector
-			return ZV
-		}
-
-		// Get minimum distance to travel out of Rect
-		rToC := r.Center().To(c.Center)
-		h := c.Radius - math.Abs(rToC.X) + (r.W() / 2)
-		v := c.Radius - math.Abs(rToC.Y) + (r.H() / 2)
-
-		if rToC.X < 0 {
-			h = -h
-		}
-		if rToC.Y < 0 {
-			v = -v
-		}
-
-		// No intersect
-		if h == 0 && v == 0 {
-			return ZV
-		}
-
-		if math.Abs(h) > math.Abs(v) {
-			// Vertical distance shorter
-			return V(0, v)
-		}
-		return V(h, 0)
-	} else {
-		// The center is in the diagonal quadrants
-
-		// Helper points to make code below easy to read.
-		rectTopLeft := V(r.Min.X, r.Max.Y)
-		rectBottomRight := V(r.Max.X, r.Min.Y)
-
-		// Check for overlap.
-		if !(c.Contains(r.Min) || c.Contains(r.Max) || c.Contains(rectTopLeft) || c.Contains(rectBottomRight)) {
-			// No overlap.
-			return ZV
-		}
-
-		var centerToCorner Vec
-		if c.Center.To(r.Min).Len() <= c.Radius {
-			// Closest to bottom-left
-			centerToCorner = c.Center.To(r.Min)
-		}
-		if c.Center.To(r.Max).Len() <= c.Radius {
-			// Closest to top-right
-			centerToCorner = c.Center.To(r.Max)
-		}
-		if c.Center.To(rectTopLeft).Len() <= c.Radius {
-			// Closest to top-left
-			centerToCorner = c.Center.To(rectTopLeft)
-		}
-		if c.Center.To(rectBottomRight).Len() <= c.Radius {
-			// Closest to bottom-right
-			centerToCorner = c.Center.To(rectBottomRight)
-		}
-
-		cornerToCircumferenceLen := c.Radius - centerToCorner.Len()
-
-		return centerToCorner.Unit().Scaled(cornerToCircumferenceLen)
-	}
-}
-
-// IntersectionPoints returns all the points where the Circle intersects with the line provided.  This can be zero, one or
-// two points, depending on the location of the shapes.  The points of intersection will be returned in order of
-// closest-to-l.A to closest-to-l.B.
-func (c Circle) IntersectionPoints(l Line) []Vec {
-	cContainsA := c.Contains(l.A)
-	cContainsB := c.Contains(l.B)
-
-	// Special case for both endpoint being contained within the circle
-	if cContainsA && cContainsB {
-		return []Vec{}
-	}
-
-	// Get closest point on the line to this circles' center
-	closestToCenter := l.Closest(c.Center)
-
-	// If the distance to the closest point is greater than the radius, there are no points of intersection
-	if closestToCenter.To(c.Center).Len() > c.Radius {
-		return []Vec{}
-	}
-
-	// If the distance to the closest point is equal to the radius, the line is tangent and the closest point is the
-	// point at which it touches the circle.
-	if closestToCenter.To(c.Center).Len() == c.Radius {
-		return []Vec{closestToCenter}
-	}
-
-	// Special case for endpoint being on the circles' center
-	if c.Center == l.A || c.Center == l.B {
-		otherEnd := l.B
-		if c.Center == l.B {
-			otherEnd = l.A
-		}
-		intersect := c.Center.Add(c.Center.To(otherEnd).Unit().Scaled(c.Radius))
-		return []Vec{intersect}
-	}
-
-	// This means the distance to the closest point is less than the radius, so there is at least one intersection,
-	// possibly two.
-
-	// If one of the end points exists within the circle, there is only one intersection
-	if cContainsA || cContainsB {
-		containedPoint := l.A
-		otherEnd := l.B
-		if cContainsB {
-			containedPoint = l.B
-			otherEnd = l.A
-		}
-
-		// Use trigonometry to get the length of the line between the contained point and the intersection point.
-		// The following is used to describe the triangle formed:
-		//  - a is the side between contained point and circle center
-		//  - b is the side between the center and the intersection point (radius)
-		//  - c is the side between the contained point and the intersection point
-		// The captials of these letters are used as the angles opposite the respective sides.
-		// a and b are known
-		a := containedPoint.To(c.Center).Len()
-		b := c.Radius
-		// B can be calculated by subtracting the angle of b (to the x-axis) from the angle of c (to the x-axis)
-		B := containedPoint.To(c.Center).Angle() - containedPoint.To(otherEnd).Angle()
-		// Using the Sin rule we can get A
-		A := math.Asin((a * math.Sin(B)) / b)
-		// Using the rule that there are 180 degrees (or Pi radians) in a triangle, we can now get C
-		C := math.Pi - A + B
-		// If C is zero, the line segment is in-line with the center-intersect line.
-		var c float64
-		if C == 0 {
-			c = b - a
-		} else {
-			// Using the Sine rule again, we can now get c
-			c = (a * math.Sin(C)) / math.Sin(A)
-		}
-		// Travelling from the contained point to the other end by length of a will provide the intersection point.
-		return []Vec{
-			containedPoint.Add(containedPoint.To(otherEnd).Unit().Scaled(c)),
-		}
-	}
-
-	// Otherwise the endpoints exist outside of the circle, and the line segment intersects in two locations.
-	// The vector formed by going from the closest point to the center of the circle will be perpendicular to the line;
-	// this forms a right-angled triangle with the intersection points, with the radius as the hypotenuse.
-	// Calculate the other triangles' sides' length.
-	a := math.Sqrt(math.Pow(c.Radius, 2) - math.Pow(closestToCenter.To(c.Center).Len(), 2))
-
-	// Travelling in both directions from the closest point by length of a will provide the two intersection points.
-	first := closestToCenter.Add(closestToCenter.To(l.A).Unit().Scaled(a))
-	second := closestToCenter.Add(closestToCenter.To(l.B).Unit().Scaled(a))
-
-	if first.To(l.A).Len() < second.To(l.A).Len() {
-		return []Vec{first, second}
-	}
-	return []Vec{second, first}
-}

circle_test.go

@@ -1,466 +0,0 @@
-package pixel_test
-
-import (
-	"math"
-	"reflect"
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-func TestC(t *testing.T) {
-	type args struct {
-		radius float64
-		center pixel.Vec
-	}
-	tests := []struct {
-		name string
-		args args
-		want pixel.Circle
-	}{
-		{
-			name: "C(): positive radius",
-			args: args{radius: 10, center: pixel.ZV},
-			want: pixel.Circle{Radius: 10, Center: pixel.ZV},
-		},
-		{
-			name: "C(): zero radius",
-			args: args{radius: 0, center: pixel.ZV},
-			want: pixel.Circle{Radius: 0, Center: pixel.ZV},
-		},
-		{
-			name: "C(): negative radius",
-			args: args{radius: -5, center: pixel.ZV},
-			want: pixel.Circle{Radius: -5, Center: pixel.ZV},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := pixel.C(tt.args.center, tt.args.radius); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("C() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_String(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   string
-	}{
-		{
-			name:   "Circle.String(): positive radius",
-			fields: fields{radius: 10, center: pixel.ZV},
-			want:   "Circle(Vec(0, 0), 10.00)",
-		},
-		{
-			name:   "Circle.String(): zero radius",
-			fields: fields{radius: 0, center: pixel.ZV},
-			want:   "Circle(Vec(0, 0), 0.00)",
-		},
-		{
-			name:   "Circle.String(): negative radius",
-			fields: fields{radius: -5, center: pixel.ZV},
-			want:   "Circle(Vec(0, 0), -5.00)",
-		},
-		{
-			name:   "Circle.String(): irrational radius",
-			fields: fields{radius: math.Pi, center: pixel.ZV},
-			want:   "Circle(Vec(0, 0), 3.14)",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(tt.fields.center, tt.fields.radius)
-			if got := c.String(); got != tt.want {
-				t.Errorf("Circle.String() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_Norm(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   pixel.Circle
-	}{
-		{
-			name:   "Circle.Norm(): positive radius",
-			fields: fields{radius: 10, center: pixel.ZV},
-			want:   pixel.C(pixel.ZV, 10),
-		},
-		{
-			name:   "Circle.Norm(): zero radius",
-			fields: fields{radius: 0, center: pixel.ZV},
-			want:   pixel.C(pixel.ZV, 0),
-		},
-		{
-			name:   "Circle.Norm(): negative radius",
-			fields: fields{radius: -5, center: pixel.ZV},
-			want:   pixel.C(pixel.ZV, 5),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(tt.fields.center, tt.fields.radius)
-			if got := c.Norm(); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Circle.Norm() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_Area(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   float64
-	}{
-		{
-			name:   "Circle.Area(): positive radius",
-			fields: fields{radius: 10, center: pixel.ZV},
-			want:   100 * math.Pi,
-		},
-		{
-			name:   "Circle.Area(): zero radius",
-			fields: fields{radius: 0, center: pixel.ZV},
-			want:   0,
-		},
-		{
-			name:   "Circle.Area(): negative radius",
-			fields: fields{radius: -5, center: pixel.ZV},
-			want:   25 * math.Pi,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(tt.fields.center, tt.fields.radius)
-			if got := c.Area(); got != tt.want {
-				t.Errorf("Circle.Area() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_Moved(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	type args struct {
-		delta pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Circle
-	}{
-		{
-			name:   "Circle.Moved(): positive movement",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{delta: pixel.V(10, 20)},
-			want:   pixel.C(pixel.V(10, 20), 10),
-		},
-		{
-			name:   "Circle.Moved(): zero movement",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{delta: pixel.ZV},
-			want:   pixel.C(pixel.V(0, 0), 10),
-		},
-		{
-			name:   "Circle.Moved(): negative movement",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{delta: pixel.V(-5, -10)},
-			want:   pixel.C(pixel.V(-5, -10), 10),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(tt.fields.center, tt.fields.radius)
-			if got := c.Moved(tt.args.delta); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Circle.Moved() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_Resized(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	type args struct {
-		radiusDelta float64
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Circle
-	}{
-		{
-			name:   "Circle.Resized(): positive delta",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{radiusDelta: 5},
-			want:   pixel.C(pixel.V(0, 0), 15),
-		},
-		{
-			name:   "Circle.Resized(): zero delta",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{radiusDelta: 0},
-			want:   pixel.C(pixel.V(0, 0), 10),
-		},
-		{
-			name:   "Circle.Resized(): negative delta",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{radiusDelta: -5},
-			want:   pixel.C(pixel.V(0, 0), 5),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(tt.fields.center, tt.fields.radius)
-			if got := c.Resized(tt.args.radiusDelta); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Circle.Resized() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_Contains(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	type args struct {
-		u pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   bool
-	}{
-		{
-			name:   "Circle.Contains(): point on cicles' center",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{u: pixel.ZV},
-			want:   true,
-		},
-		{
-			name:   "Circle.Contains(): point offcenter",
-			fields: fields{radius: 10, center: pixel.V(5, 0)},
-			args:   args{u: pixel.ZV},
-			want:   true,
-		},
-		{
-			name:   "Circle.Contains(): point on circumference",
-			fields: fields{radius: 10, center: pixel.V(10, 0)},
-			args:   args{u: pixel.ZV},
-			want:   true,
-		},
-		{
-			name:   "Circle.Contains(): point outside circle",
-			fields: fields{radius: 10, center: pixel.V(15, 0)},
-			args:   args{u: pixel.ZV},
-			want:   false,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(tt.fields.center, tt.fields.radius)
-			if got := c.Contains(tt.args.u); got != tt.want {
-				t.Errorf("Circle.Contains() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_Union(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	type args struct {
-		d pixel.Circle
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Circle
-	}{
-		{
-			name:   "Circle.Union(): overlapping circles",
-			fields: fields{radius: 5, center: pixel.ZV},
-			args:   args{d: pixel.C(pixel.ZV, 5)},
-			want:   pixel.C(pixel.ZV, 5),
-		},
-		{
-			name:   "Circle.Union(): separate circles",
-			fields: fields{radius: 1, center: pixel.ZV},
-			args:   args{d: pixel.C(pixel.V(0, 2), 1)},
-			want:   pixel.C(pixel.V(0, 1), 2),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(tt.fields.center, tt.fields.radius)
-			if got := c.Union(tt.args.d); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Circle.Union() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_Intersect(t *testing.T) {
-	type fields struct {
-		radius float64
-		center pixel.Vec
-	}
-	type args struct {
-		d pixel.Circle
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Circle
-	}{
-		{
-			name:   "Circle.Intersect(): intersecting circles",
-			fields: fields{radius: 1, center: pixel.ZV},
-			args:   args{d: pixel.C(pixel.V(1, 0), 1)},
-			want:   pixel.C(pixel.V(0.5, 0), 1),
-		},
-		{
-			name:   "Circle.Intersect(): non-intersecting circles",
-			fields: fields{radius: 1, center: pixel.ZV},
-			args:   args{d: pixel.C(pixel.V(3, 3), 1)},
-			want:   pixel.C(pixel.V(1.5, 1.5), 0),
-		},
-		{
-			name:   "Circle.Intersect(): first circle encompassing second",
-			fields: fields{radius: 10, center: pixel.ZV},
-			args:   args{d: pixel.C(pixel.V(3, 3), 1)},
-			want:   pixel.C(pixel.ZV, 10),
-		},
-		{
-			name:   "Circle.Intersect(): second circle encompassing first",
-			fields: fields{radius: 1, center: pixel.V(-1, -4)},
-			args:   args{d: pixel.C(pixel.ZV, 10)},
-			want:   pixel.C(pixel.ZV, 10),
-		},
-		{
-			name:   "Circle.Intersect(): matching circles",
-			fields: fields{radius: 1, center: pixel.ZV},
-			args:   args{d: pixel.C(pixel.ZV, 1)},
-			want:   pixel.C(pixel.ZV, 1),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.C(
-				tt.fields.center,
-				tt.fields.radius,
-			)
-			if got := c.Intersect(tt.args.d); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Circle.Intersect() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCircle_IntersectPoints(t *testing.T) {
-	type fields struct {
-		Center pixel.Vec
-		Radius float64
-	}
-	type args struct {
-		l pixel.Line
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   []pixel.Vec
-	}{
-		{
-			name:   "Line intersects circle at two points",
-			fields: fields{Center: pixel.V(2, 2), Radius: 1},
-			args:   args{pixel.L(pixel.V(0, 0), pixel.V(10, 10))},
-			want:   []pixel.Vec{pixel.V(1.292, 1.292), pixel.V(2.707, 2.707)},
-		},
-		{
-			name:   "Line intersects circle at one point",
-			fields: fields{Center: pixel.V(-0.5, -0.5), Radius: 1},
-			args:   args{pixel.L(pixel.V(0, 0), pixel.V(10, 10))},
-			want:   []pixel.Vec{pixel.V(0.207, 0.207)},
-		},
-		{
-			name:   "Line endpoint is circle center",
-			fields: fields{Center: pixel.V(0, 0), Radius: 1},
-			args:   args{pixel.L(pixel.V(0, 0), pixel.V(10, 10))},
-			want:   []pixel.Vec{pixel.V(0.707, 0.707)},
-		},
-		{
-			name:   "Both line endpoints within circle",
-			fields: fields{Center: pixel.V(0, 0), Radius: 1},
-			args:   args{pixel.L(pixel.V(0.2, 0.2), pixel.V(0.5, 0.5))},
-			want:   []pixel.Vec{},
-		},
-		{
-			name:   "Line does not intersect circle",
-			fields: fields{Center: pixel.V(10, 0), Radius: 1},
-			args:   args{pixel.L(pixel.V(0, 0), pixel.V(10, 10))},
-			want:   []pixel.Vec{},
-		},
-		{
-			name:   "Horizontal line intersects circle at two points",
-			fields: fields{Center: pixel.V(5, 5), Radius: 1},
-			args:   args{pixel.L(pixel.V(0, 5), pixel.V(10, 5))},
-			want:   []pixel.Vec{pixel.V(4, 5), pixel.V(6, 5)},
-		},
-		{
-			name:   "Vertical line intersects circle at two points",
-			fields: fields{Center: pixel.V(5, 5), Radius: 1},
-			args:   args{pixel.L(pixel.V(5, 0), pixel.V(5, 10))},
-			want:   []pixel.Vec{pixel.V(5, 4), pixel.V(5, 6)},
-		},
-		{
-			name:   "Left and down line intersects circle at two points",
-			fields: fields{Center: pixel.V(5, 5), Radius: 1},
-			args:   args{pixel.L(pixel.V(10, 10), pixel.V(0, 0))},
-			want:   []pixel.Vec{pixel.V(5.707, 5.707), pixel.V(4.292, 4.292)},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := pixel.Circle{
-				Center: tt.fields.Center,
-				Radius: tt.fields.Radius,
-			}
-			got := c.IntersectionPoints(tt.args.l)
-			for i, v := range got {
-				if !closeEnough(v.X, tt.want[i].X, 2) || !closeEnough(v.Y, tt.want[i].Y, 2) {
-					t.Errorf("Circle.IntersectPoints() = %v, want %v", v, tt.want[i])
-				}
-			}
-		})
-	}
-}

color.go

@@ -80,6 +80,14 @@ func ToRGBA(c color.Color) RGBA {
 	if c, ok := c.(RGBA); ok {
 		return c
 	}
+	if c, ok := c.(color.RGBA); ok {
+		return RGBA{
+			R: float64(c.R) / 255,
+			G: float64(c.G) / 255,
+			B: float64(c.B) / 255,
+			A: float64(c.A) / 255,
+		}
+	}
 	r, g, b, a := c.RGBA()
 	return RGBA{
 		float64(r) / 0xffff,

color_test.go

@@ -1,24 +0,0 @@
-package pixel_test
-
-import (
-	"fmt"
-	"image/color"
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-func BenchmarkColorToRGBA(b *testing.B) {
-	types := []color.Color{
-		color.NRGBA{R: 124, G: 14, B: 230, A: 42}, // slowest
-		color.RGBA{R: 62, G: 32, B: 14, A: 63},    // faster
-		pixel.RGB(0.8, 0.2, 0.5).Scaled(0.712),    // fastest
-	}
-	for _, col := range types {
-		b.Run(fmt.Sprintf("From %T", col), func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = pixel.ToRGBA(col)
-			}
-		})
-	}
-}

data.go

@@ -8,16 +8,6 @@ import (
 	"math"
 )
 
-// zeroValueTriangleData is the default value of a TriangleData element
-var zeroValueTriangleData = struct {
-	Position  Vec
-	Color     RGBA
-	Picture   Vec
-	Intensity float64
-	ClipRect  Rect
-	IsClipped bool
-}{Color: RGBA{1, 1, 1, 1}}
-
 // TrianglesData specifies a list of Triangles vertices with three common properties:
 // TrianglesPosition, TrianglesColor and TrianglesPicture.
 type TrianglesData []struct {
@@ -25,8 +15,6 @@ type TrianglesData []struct {
 	Color     RGBA
 	Picture   Vec
 	Intensity float64
-	ClipRect  Rect
-	IsClipped bool
 }
 
 // MakeTrianglesData creates TrianglesData of length len initialized with default property values.
@@ -34,11 +22,9 @@ type TrianglesData []struct {
 // Prefer this function to make(TrianglesData, len), because make zeros them, while this function
 // does the correct intialization.
 func MakeTrianglesData(len int) *TrianglesData {
-	td := make(TrianglesData, len)
-	for i := 0; i < len; i++ {
-		td[i] = zeroValueTriangleData
-	}
-	return &td
+	td := &TrianglesData{}
+	td.SetLen(len)
+	return td
 }
 
 // Len returns the number of vertices in TrianglesData.
@@ -54,7 +40,12 @@ func (td *TrianglesData) SetLen(len int) {
 	if len > td.Len() {
 		needAppend := len - td.Len()
 		for i := 0; i < needAppend; i++ {
-			*td = append(*td, zeroValueTriangleData)
+			*td = append(*td, struct {
+				Position  Vec
+				Color     RGBA
+				Picture   Vec
+				Intensity float64
+			}{ZV, Alpha(1), ZV, 0})
 		}
 	}
 	if len < td.Len() {
@@ -91,11 +82,6 @@ func (td *TrianglesData) updateData(t Triangles) {
 			(*td)[i].Picture, (*td)[i].Intensity = t.Picture(i)
 		}
 	}
-	if t, ok := t.(TrianglesClipped); ok {
-		for i := range *td {
-			(*td)[i].ClipRect, (*td)[i].IsClipped = t.ClipRect(i)
-		}
-	}
 }
 
 // Update copies vertex properties from the supplied Triangles into this TrianglesData.
@@ -110,9 +96,10 @@ func (td *TrianglesData) Update(t Triangles) {
 
 // Copy returns an exact independent copy of this TrianglesData.
 func (td *TrianglesData) Copy() Triangles {
-	copyTd := MakeTrianglesData(td.Len())
+	copyTd := TrianglesData{}
+	copyTd.SetLen(td.Len())
 	copyTd.Update(td)
-	return copyTd
+	return &copyTd
 }
 
 // Position returns the position property of i-th vertex.
@@ -130,11 +117,6 @@ func (td *TrianglesData) Picture(i int) (pic Vec, intensity float64) {
 	return (*td)[i].Picture, (*td)[i].Intensity
 }
 
-// ClipRect returns the clipping rectangle property of the i-th vertex.
-func (td *TrianglesData) ClipRect(i int) (rect Rect, has bool) {
-	return (*td)[i].ClipRect, (*td)[i].IsClipped
-}
-
 // PictureData specifies an in-memory rectangular area of pixels and implements Picture and
 // PictureColor.
 //
@@ -183,8 +165,13 @@ func verticalFlip(rgba *image.RGBA) {
 //
 // The resulting PictureData's Bounds will be the equivalent of the supplied image.Image's Bounds.
 func PictureDataFromImage(img image.Image) *PictureData {
-	rgba := image.NewRGBA(img.Bounds())
-	draw.Draw(rgba, rgba.Bounds(), img, img.Bounds().Min, draw.Src)
+	var rgba *image.RGBA
+	if rgbaImg, ok := img.(*image.RGBA); ok {
+		rgba = rgbaImg
+	} else {
+		rgba = image.NewRGBA(img.Bounds())
+		draw.Draw(rgba, rgba.Bounds(), img, img.Bounds().Min, draw.Src)
+	}
 
 	verticalFlip(rgba)
 

data_test.go

@@ -1,300 +0,0 @@
-package pixel_test
-
-import (
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-func BenchmarkMakeTrianglesData(b *testing.B) {
-	tests := []struct {
-		name string
-		len  int
-	}{
-		{
-			name: "Small slice",
-			len:  10,
-		},
-		{
-			name: "Large slice",
-			len:  10000,
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = pixel.MakeTrianglesData(tt.len)
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_Len(b *testing.B) {
-	tests := []struct {
-		name  string
-		tData *pixel.TrianglesData
-	}{
-		{
-			name:  "Small slice",
-			tData: pixel.MakeTrianglesData(10),
-		},
-		{
-			name:  "Large slice",
-			tData: pixel.MakeTrianglesData(10000),
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = tt.tData.Len()
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_SetLen(b *testing.B) {
-	tests := []struct {
-		name        string
-		tData       *pixel.TrianglesData
-		nextLenFunc func(int, int) (int, int)
-	}{
-		{
-			name:        "Stay same size",
-			tData:       pixel.MakeTrianglesData(50),
-			nextLenFunc: func(i, j int) (int, int) { return 50, 0 },
-		},
-		{
-			name:  "Change size",
-			tData: pixel.MakeTrianglesData(50),
-			nextLenFunc: func(i, j int) (int, int) {
-				// 0 is shrink
-				if j == 0 {
-					next := i - 1
-					if next < 1 {
-						return 2, 1
-					}
-					return next, 0
-				}
-
-				// other than 0 is grow
-				next := i + 1
-				if next == 100 {
-					return next, 0
-				}
-				return next, 1
-			},
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			var newLen int
-			var c int
-			for i := 0; i < b.N; i++ {
-				newLen, c = tt.nextLenFunc(newLen, c)
-				tt.tData.SetLen(newLen)
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_Slice(b *testing.B) {
-	tests := []struct {
-		name  string
-		tData *pixel.TrianglesData
-	}{
-		{
-			name:  "Basic slice",
-			tData: pixel.MakeTrianglesData(100),
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = tt.tData.Slice(25, 50)
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_Update(b *testing.B) {
-	tests := []struct {
-		name  string
-		tData *pixel.TrianglesData
-		t     pixel.Triangles
-	}{
-		{
-			name:  "Small Triangles",
-			tData: pixel.MakeTrianglesData(20),
-			t:     pixel.MakeTrianglesData(20),
-		},
-		{
-			name:  "Large Triangles",
-			tData: pixel.MakeTrianglesData(10000),
-			t:     pixel.MakeTrianglesData(10000),
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				tt.tData.Update(tt.t)
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_Copy(b *testing.B) {
-	tests := []struct {
-		name  string
-		tData *pixel.TrianglesData
-	}{
-		{
-			name:  "Small copy",
-			tData: pixel.MakeTrianglesData(20),
-		},
-		{
-			name:  "Large copy",
-			tData: pixel.MakeTrianglesData(10000),
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = tt.tData.Copy()
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_Position(b *testing.B) {
-	tests := []struct {
-		name     string
-		tData    *pixel.TrianglesData
-		position int
-	}{
-		{
-			name:     "Getting beginning position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 2,
-		},
-		{
-			name:     "Getting middle position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 500,
-		},
-		{
-			name:     "Getting end position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 999,
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = tt.tData.Position(tt.position)
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_Color(b *testing.B) {
-	tests := []struct {
-		name     string
-		tData    *pixel.TrianglesData
-		position int
-	}{
-		{
-			name:     "Getting beginning position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 2,
-		},
-		{
-			name:     "Getting middle position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 500,
-		},
-		{
-			name:     "Getting end position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 999,
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = tt.tData.Color(tt.position)
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_Picture(b *testing.B) {
-	tests := []struct {
-		name     string
-		tData    *pixel.TrianglesData
-		position int
-	}{
-		{
-			name:     "Getting beginning position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 2,
-		},
-		{
-			name:     "Getting middle position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 500,
-		},
-		{
-			name:     "Getting end position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 999,
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_, _ = tt.tData.Picture(tt.position)
-			}
-		})
-	}
-}
-
-func BenchmarkTrianglesData_ClipRect(b *testing.B) {
-	tests := []struct {
-		name     string
-		tData    *pixel.TrianglesData
-		position int
-	}{
-		{
-			name:     "Getting beginning position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 2,
-		},
-		{
-			name:     "Getting middle position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 500,
-		},
-		{
-			name:     "Getting end position",
-			tData:    pixel.MakeTrianglesData(1000),
-			position: 999,
-		},
-	}
-
-	for _, tt := range tests {
-		b.Run(tt.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_, _ = tt.tData.ClipRect(tt.position)
-			}
-		})
-	}
-}

drawer.go

@@ -23,22 +23,24 @@ package pixel
 type Drawer struct {
 	Triangles Triangles
 	Picture   Picture
-	Cached    bool
 
-	targets    map[Target]*drawerTarget
-	allTargets []*drawerTarget
-	inited     bool
+	tris   map[Target]TargetTriangles
+	clean  map[Target]bool
+	pics   map[targetPicturePair]TargetPicture
+	dirty  bool
+	inited bool
 }
 
-type drawerTarget struct {
-	tris  TargetTriangles
-	pics  map[Picture]TargetPicture
-	clean bool
+type targetPicturePair struct {
+	Target  Target
+	Picture Picture
 }
 
 func (d *Drawer) lazyInit() {
 	if !d.inited {
-		d.targets = make(map[Target]*drawerTarget)
+		d.tris = make(map[Target]TargetTriangles)
+		d.clean = make(map[Target]bool)
+		d.pics = make(map[targetPicturePair]TargetPicture)
 		d.inited = true
 	}
 }
@@ -48,9 +50,7 @@ func (d *Drawer) lazyInit() {
 func (d *Drawer) Dirty() {
 	d.lazyInit()
 
-	for _, t := range d.allTargets {
-		t.clean = false
-	}
+	d.dirty = true
 }
 
 // Draw efficiently draws Triangles with Picture onto the provided Target.
@@ -60,43 +60,40 @@ func (d *Drawer) Dirty() {
 func (d *Drawer) Draw(t Target) {
 	d.lazyInit()
 
+	if d.dirty {
+		for t := range d.clean {
+			d.clean[t] = false
+		}
+		d.dirty = false
+	}
+
 	if d.Triangles == nil {
 		return
 	}
 
-	dt := d.targets[t]
-	if dt == nil {
-		dt = &drawerTarget{
-			pics: make(map[Picture]TargetPicture),
-		}
-		d.targets[t] = dt
-		d.allTargets = append(d.allTargets, dt)
+	tri := d.tris[t]
+	if tri == nil {
+		tri = t.MakeTriangles(d.Triangles)
+		d.tris[t] = tri
+		d.clean[t] = true
 	}
 
-	if dt.tris == nil {
-		dt.tris = t.MakeTriangles(d.Triangles)
-		dt.clean = true
-	}
-
-	if !dt.clean {
-		dt.tris.SetLen(d.Triangles.Len())
-		dt.tris.Update(d.Triangles)
-		dt.clean = true
+	if !d.clean[t] {
+		tri.SetLen(d.Triangles.Len())
+		tri.Update(d.Triangles)
+		d.clean[t] = true
 	}
 
 	if d.Picture == nil {
-		dt.tris.Draw()
+		tri.Draw()
 		return
 	}
 
-	pic := dt.pics[d.Picture]
+	pic := d.pics[targetPicturePair{t, d.Picture}]
 	if pic == nil {
 		pic = t.MakePicture(d.Picture)
-
-		if d.Cached {
-			dt.pics[d.Picture] = pic
-		}
+		d.pics[targetPicturePair{t, d.Picture}] = pic
 	}
 
-	pic.Draw(dt.tris)
+	pic.Draw(tri)
 }

drawer_test.go

@@ -1,18 +0,0 @@
-package pixel_test
-
-import (
-	"image"
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-func BenchmarkSpriteDrawBatch(b *testing.B) {
-	img := image.NewRGBA(image.Rect(0, 0, 64, 64))
-	pic := pixel.PictureDataFromImage(img)
-	sprite := pixel.NewSprite(pic, pixel.R(0, 0, 64, 64))
-	batch := pixel.NewBatch(&pixel.TrianglesData{}, pic)
-	for i := 0; i < b.N; i++ {
-		sprite.Draw(batch, pixel.IM)
-	}
-}

examples/community/maze/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 stephen
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

examples/community/maze/README.md

@@ -0,0 +1,19 @@
+# Maze generator in Go
+
+Created by [Stephen Chavez](https://github.com/redragonx)
+
+This uses the game engine: Pixel. Install it here: https://github.com/faiface/pixel
+
+I made this to improve my understanding of Go and some game concepts with some basic maze generating algorithms.
+
+Controls: Press 'R' to restart the maze.
+
+Optional command-line arguments: `go run ./maze-generator.go`
+  - `-w` sets the maze's width in pixels.
+  -	`-h` sets the maze's height in pixels.
+  -	`-c` sets the maze cell's size in pixels.
+
+Code based on the Recursive backtracker algorithm. 
+- https://en.wikipedia.org/wiki/Maze_generation_algorithm#Recursive_backtracker
+
+![Screenshot](screenshot.png)

examples/community/maze/maze-generator.go

@@ -0,0 +1,317 @@
+package main
+
+// Code based on the Recursive backtracker algorithm.
+// https://en.wikipedia.org/wiki/Maze_generation_algorithm#Recursive_backtracker
+// See https://youtu.be/HyK_Q5rrcr4 as an example
+// YouTube example ported to Go for the Pixel library.
+
+// Created by Stephen Chavez
+
+import (
+	"crypto/rand"
+	"errors"
+	"flag"
+	"fmt"
+	"math/big"
+	"time"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/examples/community/maze/stack"
+	"github.com/faiface/pixel/imdraw"
+	"github.com/faiface/pixel/pixelgl"
+
+	"github.com/pkg/profile"
+	"golang.org/x/image/colornames"
+)
+
+var visitedColor = pixel.RGB(0.5, 0, 1).Mul(pixel.Alpha(0.35))
+var hightlightColor = pixel.RGB(0.3, 0, 0).Mul(pixel.Alpha(0.45))
+var debug = false
+
+type cell struct {
+	walls [4]bool // Wall order: top, right, bottom, left
+
+	row     int
+	col     int
+	visited bool
+}
+
+func (c *cell) Draw(imd *imdraw.IMDraw, wallSize int) {
+	drawCol := c.col * wallSize // x
+	drawRow := c.row * wallSize // y
+
+	imd.Color = colornames.White
+	if c.walls[0] {
+		// top line
+		imd.Push(pixel.V(float64(drawCol), float64(drawRow)), pixel.V(float64(drawCol+wallSize), float64(drawRow)))
+		imd.Line(3)
+	}
+	if c.walls[1] {
+		// right Line
+		imd.Push(pixel.V(float64(drawCol+wallSize), float64(drawRow)), pixel.V(float64(drawCol+wallSize), float64(drawRow+wallSize)))
+		imd.Line(3)
+	}
+	if c.walls[2] {
+		// bottom line
+		imd.Push(pixel.V(float64(drawCol+wallSize), float64(drawRow+wallSize)), pixel.V(float64(drawCol), float64(drawRow+wallSize)))
+		imd.Line(3)
+	}
+	if c.walls[3] {
+		// left line
+		imd.Push(pixel.V(float64(drawCol), float64(drawRow+wallSize)), pixel.V(float64(drawCol), float64(drawRow)))
+		imd.Line(3)
+	}
+	imd.EndShape = imdraw.SharpEndShape
+
+	if c.visited {
+		imd.Color = visitedColor
+		imd.Push(pixel.V(float64(drawCol), (float64(drawRow))), pixel.V(float64(drawCol+wallSize), float64(drawRow+wallSize)))
+		imd.Rectangle(0)
+	}
+}
+
+func (c *cell) GetNeighbors(grid []*cell, cols int, rows int) ([]*cell, error) {
+	neighbors := []*cell{}
+	j := c.row
+	i := c.col
+
+	top, _ := getCellAt(i, j-1, cols, rows, grid)
+	right, _ := getCellAt(i+1, j, cols, rows, grid)
+	bottom, _ := getCellAt(i, j+1, cols, rows, grid)
+	left, _ := getCellAt(i-1, j, cols, rows, grid)
+
+	if top != nil && !top.visited {
+		neighbors = append(neighbors, top)
+	}
+	if right != nil && !right.visited {
+		neighbors = append(neighbors, right)
+	}
+	if bottom != nil && !bottom.visited {
+		neighbors = append(neighbors, bottom)
+	}
+	if left != nil && !left.visited {
+		neighbors = append(neighbors, left)
+	}
+
+	if len(neighbors) == 0 {
+		return nil, errors.New("We checked all cells...")
+	}
+	return neighbors, nil
+}
+
+func (c *cell) GetRandomNeighbor(grid []*cell, cols int, rows int) (*cell, error) {
+	neighbors, err := c.GetNeighbors(grid, cols, rows)
+	if neighbors == nil {
+		return nil, err
+	}
+	nBig, err := rand.Int(rand.Reader, big.NewInt(int64(len(neighbors))))
+	if err != nil {
+		panic(err)
+	}
+	randomIndex := nBig.Int64()
+	return neighbors[randomIndex], nil
+}
+
+func (c *cell) hightlight(imd *imdraw.IMDraw, wallSize int) {
+	x := c.col * wallSize
+	y := c.row * wallSize
+
+	imd.Color = hightlightColor
+	imd.Push(pixel.V(float64(x), float64(y)), pixel.V(float64(x+wallSize), float64(y+wallSize)))
+	imd.Rectangle(0)
+}
+
+func newCell(col int, row int) *cell {
+	newCell := new(cell)
+	newCell.row = row
+	newCell.col = col
+
+	for i := range newCell.walls {
+		newCell.walls[i] = true
+	}
+	return newCell
+}
+
+// Creates the inital maze slice for use.
+func initGrid(cols, rows int) []*cell {
+	grid := []*cell{}
+	for j := 0; j < rows; j++ {
+		for i := 0; i < cols; i++ {
+			newCell := newCell(i, j)
+			grid = append(grid, newCell)
+		}
+	}
+	return grid
+}
+
+func setupMaze(cols, rows int) ([]*cell, *stack.Stack, *cell) {
+	// Make an empty grid
+	grid := initGrid(cols, rows)
+	backTrackStack := stack.NewStack(len(grid))
+	currentCell := grid[0]
+
+	return grid, backTrackStack, currentCell
+}
+
+func cellIndex(i, j, cols, rows int) int {
+	if i < 0 || j < 0 || i > cols-1 || j > rows-1 {
+		return -1
+	}
+	return i + j*cols
+}
+
+func getCellAt(i int, j int, cols int, rows int, grid []*cell) (*cell, error) {
+	possibleIndex := cellIndex(i, j, cols, rows)
+
+	if possibleIndex == -1 {
+		return nil, fmt.Errorf("cellIndex: CellIndex is a negative number %d", possibleIndex)
+	}
+	return grid[possibleIndex], nil
+}
+
+func removeWalls(a *cell, b *cell) {
+	x := a.col - b.col
+
+	if x == 1 {
+		a.walls[3] = false
+		b.walls[1] = false
+	} else if x == -1 {
+		a.walls[1] = false
+		b.walls[3] = false
+	}
+
+	y := a.row - b.row
+
+	if y == 1 {
+		a.walls[0] = false
+		b.walls[2] = false
+	} else if y == -1 {
+		a.walls[2] = false
+		b.walls[0] = false
+	}
+}
+
+func run() {
+	// unsiged integers, because easier parsing error checks.
+	// We must convert these to intergers, as done below...
+	uScreenWidth, uScreenHeight, uWallSize := parseArgs()
+
+	var (
+		// In pixels
+		// Defualt is 800x800x40 = 20x20 wallgrid
+		screenWidth  = int(uScreenWidth)
+		screenHeight = int(uScreenHeight)
+		wallSize     = int(uWallSize)
+
+		frames = 0
+		second = time.Tick(time.Second)
+
+		grid           = []*cell{}
+		cols           = screenWidth / wallSize
+		rows           = screenHeight / wallSize
+		currentCell    = new(cell)
+		backTrackStack = stack.NewStack(1)
+	)
+
+	// Set game FPS manually
+	fps := time.Tick(time.Second / 60)
+
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks! - Maze example",
+		Bounds: pixel.R(0, 0, float64(screenHeight), float64(screenWidth)),
+	}
+
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	grid, backTrackStack, currentCell = setupMaze(cols, rows)
+
+	gridIMDraw := imdraw.New(nil)
+
+	for !win.Closed() {
+		if win.JustReleased(pixelgl.KeyR) {
+			fmt.Println("R pressed")
+			grid, backTrackStack, currentCell = setupMaze(cols, rows)
+		}
+
+		win.Clear(colornames.Gray)
+		gridIMDraw.Clear()
+
+		for i := range grid {
+			grid[i].Draw(gridIMDraw, wallSize)
+		}
+
+		// step 1
+		// Make the initial cell the current cell and mark it as visited
+		currentCell.visited = true
+		currentCell.hightlight(gridIMDraw, wallSize)
+
+		// step 2.1
+		// If the current cell has any neighbours which have not been visited
+		// Choose a random unvisited cell
+		nextCell, _ := currentCell.GetRandomNeighbor(grid, cols, rows)
+		if nextCell != nil && !nextCell.visited {
+			// step 2.2
+			// Push the current cell to the stack
+			backTrackStack.Push(currentCell)
+
+			// step 2.3
+			// Remove the wall between the current cell and the chosen cell
+
+			removeWalls(currentCell, nextCell)
+
+			// step 2.4
+			// Make the chosen cell the current cell and mark it as visited
+			nextCell.visited = true
+			currentCell = nextCell
+		} else if backTrackStack.Len() > 0 {
+			currentCell = backTrackStack.Pop().(*cell)
+		}
+
+		gridIMDraw.Draw(win)
+		win.Update()
+		<-fps
+		updateFPSDisplay(win, &cfg, &frames, grid, second)
+	}
+}
+
+// Parses the maze arguments, all of them are optional.
+// Uses uint as implicit error checking :)
+func parseArgs() (uint, uint, uint) {
+	var mazeWidthPtr = flag.Uint("w", 800, "w sets the maze's width in pixels.")
+	var mazeHeightPtr = flag.Uint("h", 800, "h sets the maze's height in pixels.")
+	var wallSizePtr = flag.Uint("c", 40, "c sets the maze cell's size in pixels.")
+
+	flag.Parse()
+
+	// If these aren't default values AND if they're not the same values.
+	// We should warn the user that the maze will look funny.
+	if *mazeWidthPtr != 800 || *mazeHeightPtr != 800 {
+		if *mazeWidthPtr != *mazeHeightPtr {
+			fmt.Printf("WARNING: maze width: %d and maze height: %d don't match. \n", *mazeWidthPtr, *mazeHeightPtr)
+			fmt.Println("Maze will look funny because the maze size is bond to the window size!")
+		}
+	}
+
+	return *mazeWidthPtr, *mazeHeightPtr, *wallSizePtr
+}
+
+func updateFPSDisplay(win *pixelgl.Window, cfg *pixelgl.WindowConfig, frames *int, grid []*cell, second <-chan time.Time) {
+	*frames++
+	select {
+	case <-second:
+		win.SetTitle(fmt.Sprintf("%s | FPS: %d with %d Cells", cfg.Title, *frames, len(grid)))
+		*frames = 0
+	default:
+	}
+
+}
+
+func main() {
+	if debug {
+		defer profile.Start().Stop()
+	}
+	pixelgl.Run(run)
+}

examples/community/maze/stack/stack.go

@@ -0,0 +1,86 @@
+package stack
+
+type Stack struct {
+	top  *Element
+	size int
+	max  int
+}
+
+type Element struct {
+	value interface{}
+	next  *Element
+}
+
+func NewStack(max int) *Stack {
+	return &Stack{max: max}
+}
+
+// Return the stack's length
+func (s *Stack) Len() int {
+	return s.size
+}
+
+// Return the stack's max
+func (s *Stack) Max() int {
+	return s.max
+}
+
+// Push a new element onto the stack
+func (s *Stack) Push(value interface{}) {
+	if s.size+1 > s.max {
+		if last := s.PopLast(); last == nil {
+			panic("Unexpected nil in stack")
+		}
+	}
+	s.top = &Element{value, s.top}
+	s.size++
+}
+
+// Remove the top element from the stack and return it's value
+// If the stack is empty, return nil
+func (s *Stack) Pop() (value interface{}) {
+	if s.size > 0 {
+		value, s.top = s.top.value, s.top.next
+		s.size--
+		return
+	}
+	return nil
+}
+
+func (s *Stack) PopLast() (value interface{}) {
+	if lastElem := s.popLast(s.top); lastElem != nil {
+		return lastElem.value
+	}
+	return nil
+}
+
+//Peek returns a top without removing it from list
+func (s *Stack) Peek() (value interface{}, exists bool) {
+	exists = false
+	if s.size > 0 {
+		value = s.top.value
+		exists = true
+	}
+
+	return
+}
+
+func (s *Stack) popLast(elem *Element) *Element {
+	if elem == nil {
+		return nil
+	}
+	// not last because it has next and a grandchild
+	if elem.next != nil && elem.next.next != nil {
+		return s.popLast(elem.next)
+	}
+
+	// current elem is second from bottom, as next elem has no child
+	if elem.next != nil && elem.next.next == nil {
+		last := elem.next
+		// make current elem bottom of stack by removing its next element
+		elem.next = nil
+		s.size--
+		return last
+	}
+	return nil
+}

examples/guide/01_creating_a_window/main.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks!",
+		Bounds: pixel.R(0, 0, 1024, 768),
+		VSync:  true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	win.Clear(colornames.Skyblue)
+
+	for !win.Closed() {
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/guide/02_drawing_a_sprite/main.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"image"
+	"os"
+
+	_ "image/png"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+func loadPicture(path string) (pixel.Picture, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	img, _, err := image.Decode(file)
+	if err != nil {
+		return nil, err
+	}
+	return pixel.PictureDataFromImage(img), nil
+}
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks!",
+		Bounds: pixel.R(0, 0, 1024, 768),
+		VSync:  true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	pic, err := loadPicture("hiking.png")
+	if err != nil {
+		panic(err)
+	}
+
+	sprite := pixel.NewSprite(pic, pic.Bounds())
+
+	win.Clear(colornames.Greenyellow)
+
+	sprite.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
+
+	for !win.Closed() {
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/guide/03_moving_scaling_and_rotating_with_matrix/main.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"image"
+	"os"
+	"time"
+
+	_ "image/png"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+func loadPicture(path string) (pixel.Picture, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	img, _, err := image.Decode(file)
+	if err != nil {
+		return nil, err
+	}
+	return pixel.PictureDataFromImage(img), nil
+}
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks!",
+		Bounds: pixel.R(0, 0, 1024, 768),
+		VSync:  true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	win.SetSmooth(true)
+
+	pic, err := loadPicture("hiking.png")
+	if err != nil {
+		panic(err)
+	}
+
+	sprite := pixel.NewSprite(pic, pic.Bounds())
+
+	angle := 0.0
+
+	last := time.Now()
+	for !win.Closed() {
+		dt := time.Since(last).Seconds()
+		last = time.Now()
+
+		angle += 3 * dt
+
+		win.Clear(colornames.Firebrick)
+
+		mat := pixel.IM
+		mat = mat.Rotated(pixel.ZV, angle)
+		mat = mat.Moved(win.Bounds().Center())
+		sprite.Draw(win, mat)
+
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/guide/04_pressing_keys_and_clicking_mouse/main.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"image"
+	"math"
+	"math/rand"
+	"os"
+	"time"
+
+	_ "image/png"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+func loadPicture(path string) (pixel.Picture, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	img, _, err := image.Decode(file)
+	if err != nil {
+		return nil, err
+	}
+	return pixel.PictureDataFromImage(img), nil
+}
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks!",
+		Bounds: pixel.R(0, 0, 1024, 768),
+		VSync:  true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	spritesheet, err := loadPicture("trees.png")
+	if err != nil {
+		panic(err)
+	}
+
+	var treesFrames []pixel.Rect
+	for x := spritesheet.Bounds().Min.X; x < spritesheet.Bounds().Max.X; x += 32 {
+		for y := spritesheet.Bounds().Min.Y; y < spritesheet.Bounds().Max.Y; y += 32 {
+			treesFrames = append(treesFrames, pixel.R(x, y, x+32, y+32))
+		}
+	}
+
+	var (
+		camPos       = pixel.ZV
+		camSpeed     = 500.0
+		camZoom      = 1.0
+		camZoomSpeed = 1.2
+		trees        []*pixel.Sprite
+		matrices     []pixel.Matrix
+	)
+
+	last := time.Now()
+	for !win.Closed() {
+		dt := time.Since(last).Seconds()
+		last = time.Now()
+
+		cam := pixel.IM.Scaled(camPos, camZoom).Moved(win.Bounds().Center().Sub(camPos))
+		win.SetMatrix(cam)
+
+		if win.JustPressed(pixelgl.MouseButtonLeft) {
+			tree := pixel.NewSprite(spritesheet, treesFrames[rand.Intn(len(treesFrames))])
+			trees = append(trees, tree)
+			mouse := cam.Unproject(win.MousePosition())
+			matrices = append(matrices, pixel.IM.Scaled(pixel.ZV, 4).Moved(mouse))
+		}
+		if win.Pressed(pixelgl.KeyLeft) {
+			camPos.X -= camSpeed * dt
+		}
+		if win.Pressed(pixelgl.KeyRight) {
+			camPos.X += camSpeed * dt
+		}
+		if win.Pressed(pixelgl.KeyDown) {
+			camPos.Y -= camSpeed * dt
+		}
+		if win.Pressed(pixelgl.KeyUp) {
+			camPos.Y += camSpeed * dt
+		}
+		camZoom *= math.Pow(camZoomSpeed, win.MouseScroll().Y)
+
+		win.Clear(colornames.Forestgreen)
+
+		for i, tree := range trees {
+			tree.Draw(win, matrices[i])
+		}
+
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/guide/05_drawing_efficiently_with_batch/main.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"fmt"
+	"image"
+	"math"
+	"math/rand"
+	"os"
+	"time"
+
+	_ "image/png"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+func loadPicture(path string) (pixel.Picture, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	img, _, err := image.Decode(file)
+	if err != nil {
+		return nil, err
+	}
+	return pixel.PictureDataFromImage(img), nil
+}
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks!",
+		Bounds: pixel.R(0, 0, 1024, 768),
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	spritesheet, err := loadPicture("trees.png")
+	if err != nil {
+		panic(err)
+	}
+
+	batch := pixel.NewBatch(&pixel.TrianglesData{}, spritesheet)
+
+	var treesFrames []pixel.Rect
+	for x := spritesheet.Bounds().Min.X; x < spritesheet.Bounds().Max.X; x += 32 {
+		for y := spritesheet.Bounds().Min.Y; y < spritesheet.Bounds().Max.Y; y += 32 {
+			treesFrames = append(treesFrames, pixel.R(x, y, x+32, y+32))
+		}
+	}
+
+	var (
+		camPos       = pixel.ZV
+		camSpeed     = 500.0
+		camZoom      = 1.0
+		camZoomSpeed = 1.2
+	)
+
+	var (
+		frames = 0
+		second = time.Tick(time.Second)
+	)
+
+	last := time.Now()
+	for !win.Closed() {
+		dt := time.Since(last).Seconds()
+		last = time.Now()
+
+		cam := pixel.IM.Scaled(camPos, camZoom).Moved(win.Bounds().Center().Sub(camPos))
+		win.SetMatrix(cam)
+
+		if win.Pressed(pixelgl.MouseButtonLeft) {
+			tree := pixel.NewSprite(spritesheet, treesFrames[rand.Intn(len(treesFrames))])
+			mouse := cam.Unproject(win.MousePosition())
+			tree.Draw(batch, pixel.IM.Scaled(pixel.ZV, 4).Moved(mouse))
+		}
+		if win.Pressed(pixelgl.KeyLeft) {
+			camPos.X -= camSpeed * dt
+		}
+		if win.Pressed(pixelgl.KeyRight) {
+			camPos.X += camSpeed * dt
+		}
+		if win.Pressed(pixelgl.KeyDown) {
+			camPos.Y -= camSpeed * dt
+		}
+		if win.Pressed(pixelgl.KeyUp) {
+			camPos.Y += camSpeed * dt
+		}
+		camZoom *= math.Pow(camZoomSpeed, win.MouseScroll().Y)
+
+		win.Clear(colornames.Forestgreen)
+		batch.Draw(win)
+		win.Update()
+
+		frames++
+		select {
+		case <-second:
+			win.SetTitle(fmt.Sprintf("%s | FPS: %d", cfg.Title, frames))
+			frames = 0
+		default:
+		}
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/guide/06_drawing_shapes_with_imdraw/main.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"math"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/imdraw"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks!",
+		Bounds: pixel.R(0, 0, 1024, 768),
+		VSync:  true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	imd := imdraw.New(nil)
+
+	imd.Color = colornames.Blueviolet
+	imd.EndShape = imdraw.RoundEndShape
+	imd.Push(pixel.V(100, 100), pixel.V(700, 100))
+	imd.EndShape = imdraw.SharpEndShape
+	imd.Push(pixel.V(100, 500), pixel.V(700, 500))
+	imd.Line(30)
+
+	imd.Color = colornames.Limegreen
+	imd.Push(pixel.V(500, 500))
+	imd.Circle(300, 50)
+	imd.Color = colornames.Navy
+	imd.Push(pixel.V(200, 500), pixel.V(800, 500))
+	imd.Ellipse(pixel.V(120, 80), 0)
+
+	imd.Color = colornames.Red
+	imd.EndShape = imdraw.RoundEndShape
+	imd.Push(pixel.V(500, 350))
+	imd.CircleArc(150, -math.Pi, 0, 30)
+
+	for !win.Closed() {
+		win.Clear(colornames.Aliceblue)
+		imd.Draw(win)
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/guide/07_typing_text_on_the_screen/main.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"time"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"github.com/faiface/pixel/text"
+	"github.com/golang/freetype/truetype"
+	"golang.org/x/image/colornames"
+	"golang.org/x/image/font"
+)
+
+func loadTTF(path string, size float64) (font.Face, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	bytes, err := ioutil.ReadAll(file)
+	if err != nil {
+		return nil, err
+	}
+
+	font, err := truetype.Parse(bytes)
+	if err != nil {
+		return nil, err
+	}
+
+	return truetype.NewFace(font, &truetype.Options{
+		Size:              size,
+		GlyphCacheEntries: 1,
+	}), nil
+}
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:  "Pixel Rocks!",
+		Bounds: pixel.R(0, 0, 1024, 768),
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+	win.SetSmooth(true)
+
+	face, err := loadTTF("intuitive.ttf", 80)
+	if err != nil {
+		panic(err)
+	}
+
+	atlas := text.NewAtlas(face, text.ASCII)
+	txt := text.New(pixel.V(50, 500), atlas)
+
+	txt.Color = colornames.Lightgrey
+
+	fps := time.Tick(time.Second / 120)
+
+	for !win.Closed() {
+		txt.WriteString(win.Typed())
+		if win.JustPressed(pixelgl.KeyEnter) || win.Repeated(pixelgl.KeyEnter) {
+			txt.WriteRune('\n')
+		}
+
+		win.Clear(colornames.Darkcyan)
+		txt.Draw(win, pixel.IM.Moved(win.Bounds().Center().Sub(txt.Bounds().Center())))
+		win.Update()
+
+		<-fps
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/lights/README.md

@@ -0,0 +1,13 @@
+# Lights
+
+This example demonstrates powerful Porter-Duff composition used to create a nice noisy light effect.
+
+**Use W and S keys** to adjust the level of "dust".
+
+The FPS is limited to 30, because the effect is a little expensive and my computer couldn't handle
+60 FPS. If you have a more powerful computer (which is quite likely), peek into the code and disable
+the limit.
+
+Credit for the panda art goes to [Ján Štrba](https://www.artstation.com/artist/janstrba).
+
+![Screenshot](screenshot.png)

examples/lights/main.go

@@ -0,0 +1,195 @@
+package main
+
+import (
+	"image"
+	"math"
+	"os"
+	"time"
+
+	_ "image/jpeg"
+	_ "image/png"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/imdraw"
+	"github.com/faiface/pixel/pixelgl"
+)
+
+func loadPicture(path string) (pixel.Picture, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	img, _, err := image.Decode(file)
+	if err != nil {
+		return nil, err
+	}
+	return pixel.PictureDataFromImage(img), nil
+}
+
+type colorlight struct {
+	color  pixel.RGBA
+	point  pixel.Vec
+	angle  float64
+	radius float64
+	dust   float64
+
+	spread float64
+
+	imd *imdraw.IMDraw
+}
+
+func (cl *colorlight) apply(dst pixel.ComposeTarget, center pixel.Vec, src, noise *pixel.Sprite) {
+	// create the light arc if not created already
+	if cl.imd == nil {
+		imd := imdraw.New(nil)
+		imd.Color = pixel.Alpha(1)
+		imd.Push(pixel.ZV)
+		imd.Color = pixel.Alpha(0)
+		for angle := -cl.spread / 2; angle <= cl.spread/2; angle += cl.spread / 64 {
+			imd.Push(pixel.V(1, 0).Rotated(angle))
+		}
+		imd.Polygon(0)
+		cl.imd = imd
+	}
+
+	// draw the light arc
+	dst.SetMatrix(pixel.IM.Scaled(pixel.ZV, cl.radius).Rotated(pixel.ZV, cl.angle).Moved(cl.point))
+	dst.SetColorMask(pixel.Alpha(1))
+	dst.SetComposeMethod(pixel.ComposePlus)
+	cl.imd.Draw(dst)
+
+	// draw the noise inside the light
+	dst.SetMatrix(pixel.IM)
+	dst.SetComposeMethod(pixel.ComposeIn)
+	noise.Draw(dst, pixel.IM.Moved(center))
+
+	// draw an image inside the noisy light
+	dst.SetColorMask(cl.color)
+	dst.SetComposeMethod(pixel.ComposeIn)
+	src.Draw(dst, pixel.IM.Moved(center))
+
+	// draw the light reflected from the dust
+	dst.SetMatrix(pixel.IM.Scaled(pixel.ZV, cl.radius).Rotated(pixel.ZV, cl.angle).Moved(cl.point))
+	dst.SetColorMask(cl.color.Mul(pixel.Alpha(cl.dust)))
+	dst.SetComposeMethod(pixel.ComposePlus)
+	cl.imd.Draw(dst)
+}
+
+func run() {
+	pandaPic, err := loadPicture("panda.png")
+	if err != nil {
+		panic(err)
+	}
+	noisePic, err := loadPicture("noise.png")
+	if err != nil {
+		panic(err)
+	}
+
+	cfg := pixelgl.WindowConfig{
+		Title:  "Lights",
+		Bounds: pixel.R(0, 0, 1024, 768),
+		VSync:  true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	panda := pixel.NewSprite(pandaPic, pandaPic.Bounds())
+	noise := pixel.NewSprite(noisePic, noisePic.Bounds())
+
+	colors := []pixel.RGBA{
+		pixel.RGB(1, 0, 0),
+		pixel.RGB(0, 1, 0),
+		pixel.RGB(0, 0, 1),
+		pixel.RGB(1/math.Sqrt2, 1/math.Sqrt2, 0),
+	}
+
+	points := []pixel.Vec{
+		{X: win.Bounds().Min.X, Y: win.Bounds().Min.Y},
+		{X: win.Bounds().Max.X, Y: win.Bounds().Min.Y},
+		{X: win.Bounds().Max.X, Y: win.Bounds().Max.Y},
+		{X: win.Bounds().Min.X, Y: win.Bounds().Max.Y},
+	}
+
+	angles := []float64{
+		math.Pi / 4,
+		math.Pi/4 + math.Pi/2,
+		math.Pi/4 + 2*math.Pi/2,
+		math.Pi/4 + 3*math.Pi/2,
+	}
+
+	lights := make([]colorlight, 4)
+	for i := range lights {
+		lights[i] = colorlight{
+			color:  colors[i],
+			point:  points[i],
+			angle:  angles[i],
+			radius: 800,
+			dust:   0.3,
+			spread: math.Pi / math.E,
+		}
+	}
+
+	speed := []float64{11.0 / 23, 13.0 / 23, 17.0 / 23, 19.0 / 23}
+
+	oneLight := pixelgl.NewCanvas(win.Bounds())
+	allLight := pixelgl.NewCanvas(win.Bounds())
+
+	fps30 := time.Tick(time.Second / 30)
+
+	start := time.Now()
+	for !win.Closed() {
+		if win.Pressed(pixelgl.KeyW) {
+			for i := range lights {
+				lights[i].dust += 0.05
+				if lights[i].dust > 1 {
+					lights[i].dust = 1
+				}
+			}
+		}
+		if win.Pressed(pixelgl.KeyS) {
+			for i := range lights {
+				lights[i].dust -= 0.05
+				if lights[i].dust < 0 {
+					lights[i].dust = 0
+				}
+			}
+		}
+
+		since := time.Since(start).Seconds()
+		for i := range lights {
+			lights[i].angle = angles[i] + math.Sin(since*speed[i])*math.Pi/8
+		}
+
+		win.Clear(pixel.RGB(0, 0, 0))
+
+		// draw the panda visible outside the light
+		win.SetColorMask(pixel.Alpha(0.4))
+		win.SetComposeMethod(pixel.ComposePlus)
+		panda.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
+
+		allLight.Clear(pixel.Alpha(0))
+		allLight.SetComposeMethod(pixel.ComposePlus)
+
+		// accumulate all the lights
+		for i := range lights {
+			oneLight.Clear(pixel.Alpha(0))
+			lights[i].apply(oneLight, oneLight.Bounds().Center(), panda, noise)
+			oneLight.Draw(allLight, pixel.IM.Moved(allLight.Bounds().Center()))
+		}
+
+		// compose the final result
+		win.SetColorMask(pixel.Alpha(1))
+		allLight.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
+
+		win.Update()
+
+		<-fps30 // maintain 30 fps, because my computer couldn't handle 60 here
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/platformer/README.md

@@ -0,0 +1,14 @@
+# Platformer
+
+This example demostrates a way to put things together and create a simple platformer game with a
+Gopher!
+
+Use **arrow keys** to run and jump around. Press **ENTER** to restart. (And hush, hush, secret.
+Press TAB for slo-mo!)
+
+The retro feel is, other than from the pixel art spritesheet, achieved by using a 160x120px large
+off-screen canvas, drawing everything to it and then stretching it to fit the window.
+
+The Gopher spritesheet comes from excellent [Egon Elbre](https://github.com/egonelbre/gophers).
+
+![Screenshot](screenshot.png)

examples/platformer/main.go

@@ -0,0 +1,394 @@
+package main
+
+import (
+	"encoding/csv"
+	"image"
+	"image/color"
+	"io"
+	"math"
+	"math/rand"
+	"os"
+	"strconv"
+	"time"
+
+	_ "image/png"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/imdraw"
+	"github.com/faiface/pixel/pixelgl"
+	"github.com/pkg/errors"
+	"golang.org/x/image/colornames"
+)
+
+func loadAnimationSheet(sheetPath, descPath string, frameWidth float64) (sheet pixel.Picture, anims map[string][]pixel.Rect, err error) {
+	// total hack, nicely format the error at the end, so I don't have to type it every time
+	defer func() {
+		if err != nil {
+			err = errors.Wrap(err, "error loading animation sheet")
+		}
+	}()
+
+	// open and load the spritesheet
+	sheetFile, err := os.Open(sheetPath)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer sheetFile.Close()
+	sheetImg, _, err := image.Decode(sheetFile)
+	if err != nil {
+		return nil, nil, err
+	}
+	sheet = pixel.PictureDataFromImage(sheetImg)
+
+	// create a slice of frames inside the spritesheet
+	var frames []pixel.Rect
+	for x := 0.0; x+frameWidth <= sheet.Bounds().Max.X; x += frameWidth {
+		frames = append(frames, pixel.R(
+			x,
+			0,
+			x+frameWidth,
+			sheet.Bounds().H(),
+		))
+	}
+
+	descFile, err := os.Open(descPath)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer descFile.Close()
+
+	anims = make(map[string][]pixel.Rect)
+
+	// load the animation information, name and interval inside the spritesheet
+	desc := csv.NewReader(descFile)
+	for {
+		anim, err := desc.Read()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, nil, err
+		}
+
+		name := anim[0]
+		start, _ := strconv.Atoi(anim[1])
+		end, _ := strconv.Atoi(anim[2])
+
+		anims[name] = frames[start : end+1]
+	}
+
+	return sheet, anims, nil
+}
+
+type platform struct {
+	rect  pixel.Rect
+	color color.Color
+}
+
+func (p *platform) draw(imd *imdraw.IMDraw) {
+	imd.Color = p.color
+	imd.Push(p.rect.Min, p.rect.Max)
+	imd.Rectangle(0)
+}
+
+type gopherPhys struct {
+	gravity   float64
+	runSpeed  float64
+	jumpSpeed float64
+
+	rect   pixel.Rect
+	vel    pixel.Vec
+	ground bool
+}
+
+func (gp *gopherPhys) update(dt float64, ctrl pixel.Vec, platforms []platform) {
+	// apply controls
+	switch {
+	case ctrl.X < 0:
+		gp.vel.X = -gp.runSpeed
+	case ctrl.X > 0:
+		gp.vel.X = +gp.runSpeed
+	default:
+		gp.vel.X = 0
+	}
+
+	// apply gravity and velocity
+	gp.vel.Y += gp.gravity * dt
+	gp.rect = gp.rect.Moved(gp.vel.Scaled(dt))
+
+	// check collisions against each platform
+	gp.ground = false
+	if gp.vel.Y <= 0 {
+		for _, p := range platforms {
+			if gp.rect.Max.X <= p.rect.Min.X || gp.rect.Min.X >= p.rect.Max.X {
+				continue
+			}
+			if gp.rect.Min.Y > p.rect.Max.Y || gp.rect.Min.Y < p.rect.Max.Y+gp.vel.Y*dt {
+				continue
+			}
+			gp.vel.Y = 0
+			gp.rect = gp.rect.Moved(pixel.V(0, p.rect.Max.Y-gp.rect.Min.Y))
+			gp.ground = true
+		}
+	}
+
+	// jump if on the ground and the player wants to jump
+	if gp.ground && ctrl.Y > 0 {
+		gp.vel.Y = gp.jumpSpeed
+	}
+}
+
+type animState int
+
+const (
+	idle animState = iota
+	running
+	jumping
+)
+
+type gopherAnim struct {
+	sheet pixel.Picture
+	anims map[string][]pixel.Rect
+	rate  float64
+
+	state   animState
+	counter float64
+	dir     float64
+
+	frame pixel.Rect
+
+	sprite *pixel.Sprite
+}
+
+func (ga *gopherAnim) update(dt float64, phys *gopherPhys) {
+	ga.counter += dt
+
+	// determine the new animation state
+	var newState animState
+	switch {
+	case !phys.ground:
+		newState = jumping
+	case phys.vel.Len() == 0:
+		newState = idle
+	case phys.vel.Len() > 0:
+		newState = running
+	}
+
+	// reset the time counter if the state changed
+	if ga.state != newState {
+		ga.state = newState
+		ga.counter = 0
+	}
+
+	// determine the correct animation frame
+	switch ga.state {
+	case idle:
+		ga.frame = ga.anims["Front"][0]
+	case running:
+		i := int(math.Floor(ga.counter / ga.rate))
+		ga.frame = ga.anims["Run"][i%len(ga.anims["Run"])]
+	case jumping:
+		speed := phys.vel.Y
+		i := int((-speed/phys.jumpSpeed + 1) / 2 * float64(len(ga.anims["Jump"])))
+		if i < 0 {
+			i = 0
+		}
+		if i >= len(ga.anims["Jump"]) {
+			i = len(ga.anims["Jump"]) - 1
+		}
+		ga.frame = ga.anims["Jump"][i]
+	}
+
+	// set the facing direction of the gopher
+	if phys.vel.X != 0 {
+		if phys.vel.X > 0 {
+			ga.dir = +1
+		} else {
+			ga.dir = -1
+		}
+	}
+}
+
+func (ga *gopherAnim) draw(t pixel.Target, phys *gopherPhys) {
+	if ga.sprite == nil {
+		ga.sprite = pixel.NewSprite(nil, pixel.Rect{})
+	}
+	// draw the correct frame with the correct position and direction
+	ga.sprite.Set(ga.sheet, ga.frame)
+	ga.sprite.Draw(t, pixel.IM.
+		ScaledXY(pixel.ZV, pixel.V(
+			phys.rect.W()/ga.sprite.Frame().W(),
+			phys.rect.H()/ga.sprite.Frame().H(),
+		)).
+		ScaledXY(pixel.ZV, pixel.V(-ga.dir, 1)).
+		Moved(phys.rect.Center()),
+	)
+}
+
+type goal struct {
+	pos    pixel.Vec
+	radius float64
+	step   float64
+
+	counter float64
+	cols    [5]pixel.RGBA
+}
+
+func (g *goal) update(dt float64) {
+	g.counter += dt
+	for g.counter > g.step {
+		g.counter -= g.step
+		for i := len(g.cols) - 2; i >= 0; i-- {
+			g.cols[i+1] = g.cols[i]
+		}
+		g.cols[0] = randomNiceColor()
+	}
+}
+
+func (g *goal) draw(imd *imdraw.IMDraw) {
+	for i := len(g.cols) - 1; i >= 0; i-- {
+		imd.Color = g.cols[i]
+		imd.Push(g.pos)
+		imd.Circle(float64(i+1)*g.radius/float64(len(g.cols)), 0)
+	}
+}
+
+func randomNiceColor() pixel.RGBA {
+again:
+	r := rand.Float64()
+	g := rand.Float64()
+	b := rand.Float64()
+	len := math.Sqrt(r*r + g*g + b*b)
+	if len == 0 {
+		goto again
+	}
+	return pixel.RGB(r/len, g/len, b/len)
+}
+
+func run() {
+	rand.Seed(time.Now().UnixNano())
+
+	sheet, anims, err := loadAnimationSheet("sheet.png", "sheet.csv", 12)
+	if err != nil {
+		panic(err)
+	}
+
+	cfg := pixelgl.WindowConfig{
+		Title:  "Platformer",
+		Bounds: pixel.R(0, 0, 1024, 768),
+		VSync:  true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	phys := &gopherPhys{
+		gravity:   -512,
+		runSpeed:  64,
+		jumpSpeed: 192,
+		rect:      pixel.R(-6, -7, 6, 7),
+	}
+
+	anim := &gopherAnim{
+		sheet: sheet,
+		anims: anims,
+		rate:  1.0 / 10,
+		dir:   +1,
+	}
+
+	// hardcoded level
+	platforms := []platform{
+		{rect: pixel.R(-50, -34, 50, -32)},
+		{rect: pixel.R(20, 0, 70, 2)},
+		{rect: pixel.R(-100, 10, -50, 12)},
+		{rect: pixel.R(120, -22, 140, -20)},
+		{rect: pixel.R(120, -72, 140, -70)},
+		{rect: pixel.R(120, -122, 140, -120)},
+		{rect: pixel.R(-100, -152, 100, -150)},
+		{rect: pixel.R(-150, -127, -140, -125)},
+		{rect: pixel.R(-180, -97, -170, -95)},
+		{rect: pixel.R(-150, -67, -140, -65)},
+		{rect: pixel.R(-180, -37, -170, -35)},
+		{rect: pixel.R(-150, -7, -140, -5)},
+	}
+	for i := range platforms {
+		platforms[i].color = randomNiceColor()
+	}
+
+	gol := &goal{
+		pos:    pixel.V(-75, 40),
+		radius: 18,
+		step:   1.0 / 7,
+	}
+
+	canvas := pixelgl.NewCanvas(pixel.R(-160/2, -120/2, 160/2, 120/2))
+	imd := imdraw.New(sheet)
+	imd.Precision = 32
+
+	camPos := pixel.ZV
+
+	last := time.Now()
+	for !win.Closed() {
+		dt := time.Since(last).Seconds()
+		last = time.Now()
+
+		// lerp the camera position towards the gopher
+		camPos = pixel.Lerp(camPos, phys.rect.Center(), 1-math.Pow(1.0/128, dt))
+		cam := pixel.IM.Moved(camPos.Scaled(-1))
+		canvas.SetMatrix(cam)
+
+		// slow motion with tab
+		if win.Pressed(pixelgl.KeyTab) {
+			dt /= 8
+		}
+
+		// restart the level on pressing enter
+		if win.JustPressed(pixelgl.KeyEnter) {
+			phys.rect = phys.rect.Moved(phys.rect.Center().Scaled(-1))
+			phys.vel = pixel.ZV
+		}
+
+		// control the gopher with keys
+		ctrl := pixel.ZV
+		if win.Pressed(pixelgl.KeyLeft) {
+			ctrl.X--
+		}
+		if win.Pressed(pixelgl.KeyRight) {
+			ctrl.X++
+		}
+		if win.JustPressed(pixelgl.KeyUp) {
+			ctrl.Y = 1
+		}
+
+		// update the physics and animation
+		phys.update(dt, ctrl, platforms)
+		gol.update(dt)
+		anim.update(dt, phys)
+
+		// draw the scene to the canvas using IMDraw
+		canvas.Clear(colornames.Black)
+		imd.Clear()
+		for _, p := range platforms {
+			p.draw(imd)
+		}
+		gol.draw(imd)
+		anim.draw(imd, phys)
+		imd.Draw(canvas)
+
+		// stretch the canvas to the window
+		win.Clear(colornames.White)
+		win.SetMatrix(pixel.IM.Scaled(pixel.ZV,
+			math.Min(
+				win.Bounds().W()/canvas.Bounds().W(),
+				win.Bounds().H()/canvas.Bounds().H(),
+			),
+		).Moved(win.Bounds().Center()))
+		canvas.Draw(win, pixel.IM.Moved(canvas.Bounds().Center()))
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/platformer/sheet.csv

@@ -0,0 +1,9 @@
+Front,0,0
+FrontBlink,1,1
+LookUp,2,2
+Left,3,7
+LeftRight,4,6
+LeftBlink,7,7
+Walk,8,15
+Run,16,23
+Jump,24,26

examples/smoke/README.md

@@ -0,0 +1,8 @@
+# Smoke
+
+This example implements a smoke particle effect using sprites. It uses a spritesheet with a CSV
+description.
+
+The art in the spritesheet comes from [Kenney](https://kenney.nl/).
+
+![Screenshot](screenshot.png)

examples/smoke/blackSmoke.csv

@@ -0,0 +1,25 @@
+1543,1146,362,336
+396,0,398,364
+761,1535,386,342
+795,794,351,367
+394,1163,386,364
+1120,1163,377,348
+795,0,368,407
+0,0,395,397
+1164,0,378,415
+781,1163,338,360
+1543,0,372,370
+1148,1535,393,327
+387,1535,373,364
+396,365,371,388
+0,758,378,404
+379,758,378,371
+1543,774,360,371
+1543,1483,350,398
+0,398,382,359
+1164,416,356,382
+1164,799,369,350
+0,1535,386,394
+795,408,366,385
+1543,371,367,402
+0,1163,393,371

examples/smoke/main.go

@@ -0,0 +1,230 @@
+package main
+
+import (
+	"container/list"
+	"encoding/csv"
+	"image"
+	"io"
+	"math"
+	"math/rand"
+	"os"
+	"strconv"
+	"time"
+
+	_ "image/png"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+type particle struct {
+	Sprite     *pixel.Sprite
+	Pos        pixel.Vec
+	Rot, Scale float64
+	Mask       pixel.RGBA
+	Data       interface{}
+}
+
+type particles struct {
+	Generate            func() *particle
+	Update              func(dt float64, p *particle) bool
+	SpawnAvg, SpawnDist float64
+
+	parts     list.List
+	spawnTime float64
+}
+
+func (p *particles) UpdateAll(dt float64) {
+	p.spawnTime -= dt
+	for p.spawnTime <= 0 {
+		p.parts.PushFront(p.Generate())
+		p.spawnTime += math.Max(0, p.SpawnAvg+rand.NormFloat64()*p.SpawnDist)
+	}
+
+	for e := p.parts.Front(); e != nil; e = e.Next() {
+		part := e.Value.(*particle)
+		if !p.Update(dt, part) {
+			defer p.parts.Remove(e)
+		}
+	}
+}
+
+func (p *particles) DrawAll(t pixel.Target) {
+	for e := p.parts.Front(); e != nil; e = e.Next() {
+		part := e.Value.(*particle)
+
+		part.Sprite.DrawColorMask(
+			t,
+			pixel.IM.
+				Scaled(pixel.ZV, part.Scale).
+				Rotated(pixel.ZV, part.Rot).
+				Moved(part.Pos),
+			part.Mask,
+		)
+	}
+}
+
+type smokeData struct {
+	Vel  pixel.Vec
+	Time float64
+	Life float64
+}
+
+type smokeSystem struct {
+	Sheet pixel.Picture
+	Rects []pixel.Rect
+	Orig  pixel.Vec
+
+	VelBasis []pixel.Vec
+	VelDist  float64
+
+	LifeAvg, LifeDist float64
+}
+
+func (ss *smokeSystem) Generate() *particle {
+	sd := new(smokeData)
+	for _, base := range ss.VelBasis {
+		c := math.Max(0, 1+rand.NormFloat64()*ss.VelDist)
+		sd.Vel = sd.Vel.Add(base.Scaled(c))
+	}
+	sd.Vel = sd.Vel.Scaled(1 / float64(len(ss.VelBasis)))
+	sd.Life = math.Max(0, ss.LifeAvg+rand.NormFloat64()*ss.LifeDist)
+
+	p := new(particle)
+	p.Data = sd
+
+	p.Pos = ss.Orig
+	p.Scale = 1
+	p.Mask = pixel.Alpha(1)
+	p.Sprite = pixel.NewSprite(ss.Sheet, ss.Rects[rand.Intn(len(ss.Rects))])
+
+	return p
+}
+
+func (ss *smokeSystem) Update(dt float64, p *particle) bool {
+	sd := p.Data.(*smokeData)
+	sd.Time += dt
+
+	frac := sd.Time / sd.Life
+
+	p.Pos = p.Pos.Add(sd.Vel.Scaled(dt))
+	p.Scale = 0.5 + frac*1.5
+
+	const (
+		fadeIn  = 0.2
+		fadeOut = 0.4
+	)
+	if frac < fadeIn {
+		p.Mask = pixel.Alpha(math.Pow(frac/fadeIn, 0.75))
+	} else if frac >= fadeOut {
+		p.Mask = pixel.Alpha(math.Pow(1-(frac-fadeOut)/(1-fadeOut), 1.5))
+	} else {
+		p.Mask = pixel.Alpha(1)
+	}
+
+	return sd.Time < sd.Life
+}
+
+func loadSpriteSheet(sheetPath, descriptionPath string) (sheet pixel.Picture, rects []pixel.Rect, err error) {
+	sheetFile, err := os.Open(sheetPath)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer sheetFile.Close()
+
+	sheetImg, _, err := image.Decode(sheetFile)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	sheet = pixel.PictureDataFromImage(sheetImg)
+
+	descriptionFile, err := os.Open(descriptionPath)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer descriptionFile.Close()
+
+	description := csv.NewReader(descriptionFile)
+	for {
+		record, err := description.Read()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, nil, err
+		}
+
+		x, _ := strconv.ParseFloat(record[0], 64)
+		y, _ := strconv.ParseFloat(record[1], 64)
+		w, _ := strconv.ParseFloat(record[2], 64)
+		h, _ := strconv.ParseFloat(record[3], 64)
+
+		y = sheet.Bounds().H() - y - h
+
+		rects = append(rects, pixel.R(x, y, x+w, y+h))
+	}
+
+	return sheet, rects, nil
+}
+
+func run() {
+	sheet, rects, err := loadSpriteSheet("blackSmoke.png", "blackSmoke.csv")
+	if err != nil {
+		panic(err)
+	}
+
+	cfg := pixelgl.WindowConfig{
+		Title:     "Smoke",
+		Bounds:    pixel.R(0, 0, 1024, 768),
+		Resizable: true,
+		VSync:     true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	ss := &smokeSystem{
+		Rects:    rects,
+		Orig:     pixel.ZV,
+		VelBasis: []pixel.Vec{pixel.V(-100, 100), pixel.V(100, 100), pixel.V(0, 100)},
+		VelDist:  0.1,
+		LifeAvg:  7,
+		LifeDist: 0.5,
+	}
+
+	p := &particles{
+		Generate:  ss.Generate,
+		Update:    ss.Update,
+		SpawnAvg:  0.3,
+		SpawnDist: 0.1,
+	}
+
+	batch := pixel.NewBatch(&pixel.TrianglesData{}, sheet)
+
+	last := time.Now()
+	for !win.Closed() {
+		dt := time.Since(last).Seconds()
+		last = time.Now()
+
+		p.UpdateAll(dt)
+
+		win.Clear(colornames.Aliceblue)
+
+		orig := win.Bounds().Center()
+		orig.Y -= win.Bounds().H() / 2
+		win.SetMatrix(pixel.IM.Moved(orig))
+
+		batch.Clear()
+		p.DrawAll(batch)
+		batch.Draw(win)
+
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/typewriter/README.md

@@ -0,0 +1,13 @@
+# Typewriter
+
+This example demonstrates text drawing and text input facilities by implementing a fancy typewriter
+with a red laser cursor. Screen shakes a bit when typing and some letters turn bold or italic
+randomly.
+
+ASCII and Latin characters are supported here. Feel free to add support for more characters in the
+code (it's easy, but increases load time).
+
+The seemingly buggy letters (one over another) in the screenshot are not bugs, but a result of using
+the typewriter backspace functionality.
+
+![Screenshot](screenshot.png)

examples/typewriter/main.go

@@ -0,0 +1,317 @@
+package main
+
+import (
+	"image/color"
+	"math"
+	"math/rand"
+	"sync"
+	"time"
+	"unicode"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/imdraw"
+	"github.com/faiface/pixel/pixelgl"
+	"github.com/faiface/pixel/text"
+	"github.com/golang/freetype/truetype"
+	"golang.org/x/image/colornames"
+	"golang.org/x/image/font"
+	"golang.org/x/image/font/gofont/gobold"
+	"golang.org/x/image/font/gofont/goitalic"
+	"golang.org/x/image/font/gofont/goregular"
+)
+
+func ttfFromBytesMust(b []byte, size float64) font.Face {
+	ttf, err := truetype.Parse(b)
+	if err != nil {
+		panic(err)
+	}
+	return truetype.NewFace(ttf, &truetype.Options{
+		Size:              size,
+		GlyphCacheEntries: 1,
+	})
+}
+
+type typewriter struct {
+	mu sync.Mutex
+
+	regular *text.Text
+	bold    *text.Text
+	italic  *text.Text
+
+	offset   pixel.Vec
+	position pixel.Vec
+	move     pixel.Vec
+}
+
+func newTypewriter(c color.Color, regular, bold, italic *text.Atlas) *typewriter {
+	tw := &typewriter{
+		regular: text.New(pixel.ZV, regular),
+		bold:    text.New(pixel.ZV, bold),
+		italic:  text.New(pixel.ZV, italic),
+	}
+	tw.regular.Color = c
+	tw.bold.Color = c
+	tw.italic.Color = c
+	return tw
+}
+
+func (tw *typewriter) Ribbon(r rune) {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+
+	dice := rand.Intn(21)
+	switch {
+	case 0 <= dice && dice <= 18:
+		tw.regular.WriteRune(r)
+	case dice == 19:
+		tw.bold.Dot = tw.regular.Dot
+		tw.bold.WriteRune(r)
+		tw.regular.Dot = tw.bold.Dot
+	case dice == 20:
+		tw.italic.Dot = tw.regular.Dot
+		tw.italic.WriteRune(r)
+		tw.regular.Dot = tw.italic.Dot
+	}
+}
+
+func (tw *typewriter) Back() {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+	tw.regular.Dot = tw.regular.Dot.Sub(pixel.V(tw.regular.Atlas().Glyph(' ').Advance, 0))
+}
+
+func (tw *typewriter) Offset(off pixel.Vec) {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+	tw.offset = tw.offset.Add(off)
+}
+
+func (tw *typewriter) Position() pixel.Vec {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+	return tw.position
+}
+
+func (tw *typewriter) Move(vel pixel.Vec) {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+	tw.move = vel
+}
+
+func (tw *typewriter) Dot() pixel.Vec {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+	return tw.regular.Dot
+}
+
+func (tw *typewriter) Update(dt float64) {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+	tw.position = tw.position.Add(tw.move.Scaled(dt))
+}
+
+func (tw *typewriter) Draw(t pixel.Target, m pixel.Matrix) {
+	tw.mu.Lock()
+	defer tw.mu.Unlock()
+
+	m = pixel.IM.Moved(tw.position.Add(tw.offset)).Chained(m)
+	tw.regular.Draw(t, m)
+	tw.bold.Draw(t, m)
+	tw.italic.Draw(t, m)
+}
+
+func typeRune(tw *typewriter, r rune) {
+	tw.Ribbon(r)
+	if !unicode.IsSpace(r) {
+		go shake(tw, 3, 17)
+	}
+}
+
+func back(tw *typewriter) {
+	tw.Back()
+}
+
+func shake(tw *typewriter, intensity, friction float64) {
+	const (
+		freq = 24
+		dt   = 1.0 / freq
+	)
+	ticker := time.NewTicker(time.Second / freq)
+	defer ticker.Stop()
+
+	off := pixel.ZV
+
+	for range ticker.C {
+		tw.Offset(off.Scaled(-1))
+
+		if intensity < 0.01*dt {
+			break
+		}
+
+		off = pixel.V((rand.Float64()-0.5)*intensity*2, (rand.Float64()-0.5)*intensity*2)
+		intensity -= friction * dt
+
+		tw.Offset(off)
+	}
+}
+
+func scroll(tw *typewriter, intensity, speedUp float64) {
+	const (
+		freq = 120
+		dt   = 1.0 / freq
+	)
+	ticker := time.NewTicker(time.Second / freq)
+	defer ticker.Stop()
+
+	speed := 0.0
+
+	for range ticker.C {
+		if math.Abs(tw.Dot().Y+tw.Position().Y) < 0.01 {
+			break
+		}
+
+		targetSpeed := -(tw.Dot().Y + tw.Position().Y) * intensity
+		if speed < targetSpeed {
+			speed += speedUp * dt
+		} else {
+			speed = targetSpeed
+		}
+
+		tw.Move(pixel.V(0, speed))
+	}
+}
+
+type dotlight struct {
+	tw           *typewriter
+	color        color.Color
+	radius       float64
+	intensity    float64
+	acceleration float64
+	maxSpeed     float64
+
+	pos pixel.Vec
+	vel pixel.Vec
+
+	imd *imdraw.IMDraw
+}
+
+func newDotlight(tw *typewriter, c color.Color, radius, intensity, acceleration, maxSpeed float64) *dotlight {
+	return &dotlight{
+		tw:           tw,
+		color:        c,
+		radius:       radius,
+		intensity:    intensity,
+		acceleration: acceleration,
+		maxSpeed:     maxSpeed,
+		pos:          tw.Dot(),
+		vel:          pixel.ZV,
+		imd:          imdraw.New(nil),
+	}
+}
+
+func (dl *dotlight) Update(dt float64) {
+	targetVel := dl.tw.Dot().Add(dl.tw.Position()).Sub(dl.pos).Scaled(dl.intensity)
+	acc := targetVel.Sub(dl.vel).Scaled(dl.acceleration)
+	dl.vel = dl.vel.Add(acc.Scaled(dt))
+	if dl.vel.Len() > dl.maxSpeed {
+		dl.vel = dl.vel.Unit().Scaled(dl.maxSpeed)
+	}
+	dl.pos = dl.pos.Add(dl.vel.Scaled(dt))
+}
+
+func (dl *dotlight) Draw(t pixel.Target, m pixel.Matrix) {
+	dl.imd.Clear()
+	dl.imd.SetMatrix(m)
+	dl.imd.Color = dl.color
+	dl.imd.Push(dl.pos)
+	dl.imd.Color = pixel.Alpha(0)
+	for i := 0.0; i <= 32; i++ {
+		angle := i * 2 * math.Pi / 32
+		dl.imd.Push(dl.pos.Add(pixel.V(dl.radius, 0).Rotated(angle)))
+	}
+	dl.imd.Polygon(0)
+	dl.imd.Draw(t)
+}
+
+func run() {
+	rand.Seed(time.Now().UnixNano())
+
+	cfg := pixelgl.WindowConfig{
+		Title:     "Typewriter",
+		Bounds:    pixel.R(0, 0, 1024, 768),
+		Resizable: true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+	win.SetSmooth(true)
+
+	var (
+		regular = text.NewAtlas(
+			ttfFromBytesMust(goregular.TTF, 42),
+			text.ASCII, text.RangeTable(unicode.Latin),
+		)
+		bold = text.NewAtlas(
+			ttfFromBytesMust(gobold.TTF, 42),
+			text.ASCII, text.RangeTable(unicode.Latin),
+		)
+		italic = text.NewAtlas(
+			ttfFromBytesMust(goitalic.TTF, 42),
+			text.ASCII, text.RangeTable(unicode.Latin),
+		)
+
+		bgColor = color.RGBA{
+			R: 241,
+			G: 241,
+			B: 212,
+			A: 255,
+		}
+		fgColor = color.RGBA{
+			R: 0,
+			G: 15,
+			B: 85,
+			A: 255,
+		}
+
+		tw = newTypewriter(pixel.ToRGBA(fgColor).Scaled(0.9), regular, bold, italic)
+		dl = newDotlight(tw, colornames.Red, 6, 30, 20, 1600)
+	)
+
+	fps := time.Tick(time.Second / 120)
+	last := time.Now()
+	for !win.Closed() {
+		for _, r := range win.Typed() {
+			go typeRune(tw, r)
+		}
+		if win.JustPressed(pixelgl.KeyTab) || win.Repeated(pixelgl.KeyTab) {
+			go typeRune(tw, '\t')
+		}
+		if win.JustPressed(pixelgl.KeyEnter) || win.Repeated(pixelgl.KeyEnter) {
+			go typeRune(tw, '\n')
+			go scroll(tw, 20, 6400)
+		}
+		if win.JustPressed(pixelgl.KeyBackspace) || win.Repeated(pixelgl.KeyBackspace) {
+			go back(tw)
+		}
+
+		dt := time.Since(last).Seconds()
+		last = time.Now()
+
+		tw.Update(dt)
+		dl.Update(dt)
+
+		win.Clear(bgColor)
+
+		m := pixel.IM.Moved(pixel.V(32, 32))
+		tw.Draw(win, m)
+		dl.Draw(win, m)
+
+		win.Update()
+		<-fps
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

examples/xor/README.md

@@ -0,0 +1,8 @@
+# Xor
+
+This example demonstrates an unusual Porter-Duff composition method: Xor. (And the capability of
+drawing circles.)
+
+Just thought it was cool.
+
+![Screenshot](screenshot.png)

examples/xor/main.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"math"
+	"time"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/imdraw"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+func run() {
+	cfg := pixelgl.WindowConfig{
+		Title:     "Xor",
+		Bounds:    pixel.R(0, 0, 1024, 768),
+		Resizable: true,
+		VSync:     true,
+	}
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	imd := imdraw.New(nil)
+
+	canvas := pixelgl.NewCanvas(win.Bounds())
+
+	start := time.Now()
+	for !win.Closed() {
+		// in case window got resized, we also need to resize our canvas
+		canvas.SetBounds(win.Bounds())
+
+		offset := math.Sin(time.Since(start).Seconds()) * 300
+
+		// clear the canvas to be totally transparent and set the xor compose method
+		canvas.Clear(pixel.Alpha(0))
+		canvas.SetComposeMethod(pixel.ComposeXor)
+
+		// red circle
+		imd.Clear()
+		imd.Color = pixel.RGB(1, 0, 0)
+		imd.Push(win.Bounds().Center().Add(pixel.V(-offset, 0)))
+		imd.Circle(200, 0)
+		imd.Draw(canvas)
+
+		// blue circle
+		imd.Clear()
+		imd.Color = pixel.RGB(0, 0, 1)
+		imd.Push(win.Bounds().Center().Add(pixel.V(offset, 0)))
+		imd.Circle(150, 0)
+		imd.Draw(canvas)
+
+		// yellow circle
+		imd.Clear()
+		imd.Color = pixel.RGB(1, 1, 0)
+		imd.Push(win.Bounds().Center().Add(pixel.V(0, -offset)))
+		imd.Circle(100, 0)
+		imd.Draw(canvas)
+
+		// magenta circle
+		imd.Clear()
+		imd.Color = pixel.RGB(1, 0, 1)
+		imd.Push(win.Bounds().Center().Add(pixel.V(0, offset)))
+		imd.Circle(50, 0)
+		imd.Draw(canvas)
+
+		win.Clear(colornames.Green)
+		canvas.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
+		win.Update()
+	}
+}
+
+func main() {
+	pixelgl.Run(run)
+}

geometry.go

@@ -0,0 +1,337 @@
+package pixel
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/go-gl/mathgl/mgl64"
+)
+
+// Vec is a 2D vector type with X and Y coordinates.
+//
+// Create vectors with the V constructor:
+//
+//   u := pixel.V(1, 2)
+//   v := pixel.V(8, -3)
+//
+// Use various methods to manipulate them:
+//
+//   w := u.Add(v)
+//   fmt.Println(w)        // Vec(9, -1)
+//   fmt.Println(u.Sub(v)) // Vec(-7, 5)
+//   u = pixel.V(2, 3)
+//   v = pixel.V(8, 1)
+//   if u.X < 0 {
+//	     fmt.Println("this won't happen")
+//   }
+//   x := u.Unit().Dot(v.Unit())
+type Vec struct {
+	X, Y float64
+}
+
+// ZV is a zero vector.
+var ZV = Vec{0, 0}
+
+// V returns a new 2D vector with the given coordinates.
+func V(x, y float64) Vec {
+	return Vec{x, y}
+}
+
+// String returns the string representation of the vector u.
+//
+//   u := pixel.V(4.5, -1.3)
+//   u.String()     // returns "Vec(4.5, -1.3)"
+//   fmt.Println(u) // Vec(4.5, -1.3)
+func (u Vec) String() string {
+	return fmt.Sprintf("Vec(%v, %v)", u.X, u.Y)
+}
+
+// XY returns the components of the vector in two return values.
+func (u Vec) XY() (x, y float64) {
+	return u.X, u.Y
+}
+
+// Add returns the sum of vectors u and v.
+func (u Vec) Add(v Vec) Vec {
+	return Vec{
+		u.X + v.X,
+		u.Y + v.Y,
+	}
+}
+
+// Sub returns the difference betweeen vectors u and v.
+func (u Vec) Sub(v Vec) Vec {
+	return Vec{
+		u.X - v.X,
+		u.Y - v.Y,
+	}
+}
+
+// Scaled returns the vector u multiplied by c.
+func (u Vec) Scaled(c float64) Vec {
+	return Vec{u.X * c, u.Y * c}
+}
+
+// ScaledXY returns the vector u multiplied by the vector v component-wise.
+func (u Vec) ScaledXY(v Vec) Vec {
+	return Vec{u.X * v.X, u.Y * v.Y}
+}
+
+// Len returns the length of the vector u.
+func (u Vec) Len() float64 {
+	return math.Hypot(u.X, u.Y)
+}
+
+// Angle returns the angle between the vector u and the x-axis. The result is in range [-Pi, Pi].
+func (u Vec) Angle() float64 {
+	return math.Atan2(u.Y, u.X)
+}
+
+// Unit returns a vector of length 1 facing the direction of u (has the same angle).
+func (u Vec) Unit() Vec {
+	if u.X == 0 && u.Y == 0 {
+		return Vec{1, 0}
+	}
+	return u.Scaled(1 / u.Len())
+}
+
+// Rotated returns the vector u rotated by the given angle in radians.
+func (u Vec) Rotated(angle float64) Vec {
+	sin, cos := math.Sincos(angle)
+	return Vec{
+		u.X*cos - u.Y*sin,
+		u.X*sin + u.Y*cos,
+	}
+}
+
+// Dot returns the dot product of vectors u and v.
+func (u Vec) Dot(v Vec) float64 {
+	return u.X*v.X + u.Y*v.Y
+}
+
+// Cross return the cross product of vectors u and v.
+func (u Vec) Cross(v Vec) float64 {
+	return u.X*v.Y - v.X*u.Y
+}
+
+// Map applies the function f to both x and y components of the vector u and returns the modified
+// vector.
+//
+//   u := pixel.V(10.5, -1.5)
+//   v := u.Map(math.Floor)   // v is Vec(10, -2), both components of u floored
+func (u Vec) Map(f func(float64) float64) Vec {
+	return Vec{
+		f(u.X),
+		f(u.Y),
+	}
+}
+
+// Lerp returns a linear interpolation between vectors a and b.
+//
+// This function basically returns a point along the line between a and b and t chooses which one.
+// If t is 0, then a will be returned, if t is 1, b will be returned. Anything between 0 and 1 will
+// return the appropriate point between a and b and so on.
+func Lerp(a, b Vec, t float64) Vec {
+	return a.Scaled(1 - t).Add(b.Scaled(t))
+}
+
+// Rect is a 2D rectangle aligned with the axes of the coordinate system. It is defined by two
+// points, Min and Max.
+//
+// The invariant should hold, that Max's components are greater or equal than Min's components
+// respectively.
+type Rect struct {
+	Min, Max Vec
+}
+
+// R returns a new Rect with given the Min and Max coordinates.
+//
+// Note that the returned rectangle is not automatically normalized.
+func R(minX, minY, maxX, maxY float64) Rect {
+	return Rect{
+		Min: V(minX, minY),
+		Max: V(maxX, maxY),
+	}
+}
+
+// String returns the string representation of the Rect.
+//
+//   r := pixel.R(100, 50, 200, 300)
+//   r.String()     // returns "Rect(100, 50, 200, 300)"
+//   fmt.Println(r) // Rect(100, 50, 200, 300)
+func (r Rect) String() string {
+	return fmt.Sprintf("Rect(%v, %v, %v, %v)", r.Min.X, r.Min.Y, r.Max.X, r.Max.Y)
+}
+
+// Norm returns the Rect in normal form, such that Max is component-wise greater or equal than Min.
+func (r Rect) Norm() Rect {
+	return Rect{
+		Min: Vec{
+			math.Min(r.Min.X, r.Max.X),
+			math.Min(r.Min.Y, r.Max.Y),
+		},
+		Max: Vec{
+			math.Max(r.Min.X, r.Max.X),
+			math.Max(r.Min.Y, r.Max.Y),
+		},
+	}
+}
+
+// W returns the width of the Rect.
+func (r Rect) W() float64 {
+	return r.Max.X - r.Min.X
+}
+
+// H returns the height of the Rect.
+func (r Rect) H() float64 {
+	return r.Max.Y - r.Min.Y
+}
+
+// Size returns the vector of width and height of the Rect.
+func (r Rect) Size() Vec {
+	return V(r.W(), r.H())
+}
+
+// Center returns the position of the center of the Rect.
+func (r Rect) Center() Vec {
+	return Lerp(r.Min, r.Max, 0.5)
+}
+
+// Moved returns the Rect moved (both Min and Max) by the given vector delta.
+func (r Rect) Moved(delta Vec) Rect {
+	return Rect{
+		Min: r.Min.Add(delta),
+		Max: r.Max.Add(delta),
+	}
+}
+
+// Resized returns the Rect resized to the given size while keeping the position of the given
+// anchor.
+//
+//   r.Resized(r.Min, size)      // resizes while keeping the position of the lower-left corner
+//   r.Resized(r.Max, size)      // same with the top-right corner
+//   r.Resized(r.Center(), size) // resizes around the center
+//
+// This function does not make sense for resizing a rectangle of zero area and will panic. Use
+// ResizedMin in the case of zero area.
+func (r Rect) Resized(anchor, size Vec) Rect {
+	if r.W()*r.H() == 0 {
+		panic(fmt.Errorf("(%T).Resize: zero area", r))
+	}
+	fraction := Vec{size.X / r.W(), size.Y / r.H()}
+	return Rect{
+		Min: anchor.Add(r.Min.Sub(anchor)).ScaledXY(fraction),
+		Max: anchor.Add(r.Max.Sub(anchor)).ScaledXY(fraction),
+	}
+}
+
+// ResizedMin returns the Rect resized to the given size while keeping the position of the Rect's
+// Min.
+//
+// Sizes of zero area are safe here.
+func (r Rect) ResizedMin(size Vec) Rect {
+	return Rect{
+		Min: r.Min,
+		Max: r.Min.Add(size),
+	}
+}
+
+// Contains checks whether a vector u is contained within this Rect (including it's borders).
+func (r Rect) Contains(u Vec) bool {
+	return r.Min.X <= u.X && u.X <= r.Max.X && r.Min.Y <= u.Y && u.Y <= r.Max.Y
+}
+
+// Union returns a minimal Rect which covers both r and s. Rects r and s should be normalized.
+func (r Rect) Union(s Rect) Rect {
+	return R(
+		math.Min(r.Min.X, s.Min.X),
+		math.Min(r.Min.Y, s.Min.Y),
+		math.Max(r.Max.X, s.Max.X),
+		math.Max(r.Max.Y, s.Max.Y),
+	)
+}
+
+// Matrix is a 3x3 transformation matrix that can be used for all kinds of spacial transforms, such
+// as movement, scaling and rotations.
+//
+// Matrix has a handful of useful methods, each of which adds a transformation to the matrix. For
+// example:
+//
+//   pixel.IM.Moved(pixel.V(100, 200)).Rotated(pixel.ZV, math.Pi/2)
+//
+// This code creates a Matrix that first moves everything by 100 units horizontally and 200 units
+// vertically and then rotates everything by 90 degrees around the origin.
+type Matrix [9]float64
+
+// IM stands for identity matrix. Does nothing, no transformation.
+var IM = Matrix(mgl64.Ident3())
+
+// String returns a string representation of the Matrix.
+//
+//   m := pixel.IM
+//   fmt.Println(m) // Matrix(1 0 0 | 0 1 0 | 0 0 1)
+func (m Matrix) String() string {
+	return fmt.Sprintf(
+		"Matrix(%v %v %v | %v %v %v | %v %v %v)",
+		m[0], m[3], m[6],
+		m[1], m[4], m[7],
+		m[2], m[5], m[8],
+	)
+}
+
+// Moved moves everything by the delta vector.
+func (m Matrix) Moved(delta Vec) Matrix {
+	m3 := mgl64.Mat3(m)
+	m3 = mgl64.Translate2D(delta.XY()).Mul3(m3)
+	return Matrix(m3)
+}
+
+// ScaledXY scales everything around a given point by the scale factor in each axis respectively.
+func (m Matrix) ScaledXY(around Vec, scale Vec) Matrix {
+	m3 := mgl64.Mat3(m)
+	m3 = mgl64.Translate2D(around.Scaled(-1).XY()).Mul3(m3)
+	m3 = mgl64.Scale2D(scale.XY()).Mul3(m3)
+	m3 = mgl64.Translate2D(around.XY()).Mul3(m3)
+	return Matrix(m3)
+}
+
+// Scaled scales everything around a given point by the scale factor.
+func (m Matrix) Scaled(around Vec, scale float64) Matrix {
+	return m.ScaledXY(around, V(scale, scale))
+}
+
+// Rotated rotates everything around a given point by the given angle in radians.
+func (m Matrix) Rotated(around Vec, angle float64) Matrix {
+	m3 := mgl64.Mat3(m)
+	m3 = mgl64.Translate2D(around.Scaled(-1).XY()).Mul3(m3)
+	m3 = mgl64.Rotate3DZ(angle).Mul3(m3)
+	m3 = mgl64.Translate2D(around.XY()).Mul3(m3)
+	return Matrix(m3)
+}
+
+// Chained adds another Matrix to this one. All tranformations by the next Matrix will be applied
+// after the transformations of this Matrix.
+func (m Matrix) Chained(next Matrix) Matrix {
+	m3 := mgl64.Mat3(m)
+	m3 = mgl64.Mat3(next).Mul3(m3)
+	return Matrix(m3)
+}
+
+// Project applies all transformations added to the Matrix to a vector u and returns the result.
+//
+// Time complexity is O(1).
+func (m Matrix) Project(u Vec) Vec {
+	m3 := mgl64.Mat3(m)
+	proj := m3.Mul3x1(mgl64.Vec3{u.X, u.Y, 1})
+	return V(proj.X(), proj.Y())
+}
+
+// Unproject does the inverse operation to Project.
+//
+// Time complexity is O(1).
+func (m Matrix) Unproject(u Vec) Vec {
+	m3 := mgl64.Mat3(m)
+	inv := m3.Inv()
+	unproj := inv.Mul3x1(mgl64.Vec3{u.X, u.Y, 1})
+	return V(unproj.X(), unproj.Y())
+}

go.mod

@@ -1,15 +0,0 @@
-module github.com/faiface/pixel
-
-go 1.12
-
-require (
-	github.com/faiface/glhf v0.0.0-20211013000516-57b20770c369
-	github.com/faiface/mainthread v0.0.0-20171120011319-8b78f0a41ae3
-	github.com/go-gl/gl v0.0.0-20210905235341-f7a045908259
-	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20210727001814-0db043d8d5be
-	github.com/go-gl/mathgl v1.0.0
-	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
-	github.com/pkg/errors v0.9.1
-	github.com/stretchr/testify v1.7.0
-	golang.org/x/image v0.5.0
-)

go.sum

@@ -1,54 +0,0 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/faiface/glhf v0.0.0-20211013000516-57b20770c369 h1:gv4BgP50atccdK/1tZHDyP6rMwiiutR2HPreR/OyLzI=
-github.com/faiface/glhf v0.0.0-20211013000516-57b20770c369/go.mod h1:dDdUO+G9ZnJ9sc8nIUvhLkE45k8PEKW6+A3TdWsfpV0=
-github.com/faiface/mainthread v0.0.0-20171120011319-8b78f0a41ae3 h1:baVdMKlASEHrj19iqjARrPbaRisD7EuZEVJj6ZMLl1Q=
-github.com/faiface/mainthread v0.0.0-20171120011319-8b78f0a41ae3/go.mod h1:VEPNJUlxl5KdWjDvz6Q1l+rJlxF2i6xqDeGuGAxa87M=
-github.com/go-gl/gl v0.0.0-20210905235341-f7a045908259 h1:8q7+xl2D2qHPLTII1t4vSMNP2VKwDcn+Avf2WXvdB1A=
-github.com/go-gl/gl v0.0.0-20210905235341-f7a045908259/go.mod h1:wjpnOv6ONl2SuJSxqCPVaPZibGFdSci9HFocT9qtVYM=
-github.com/go-gl/glfw v0.0.0-20210727001814-0db043d8d5be h1:UVW91pfMB1GRQfVwC7//RGVbqX6Ea8jURmJhlANak1M=
-github.com/go-gl/glfw v0.0.0-20210727001814-0db043d8d5be/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
-github.com/go-gl/glfw/v3.3/glfw v0.0.0-20210727001814-0db043d8d5be h1:vEIVIuBApEBQTEJt19GfhoU+zFSV+sNTa9E9FdnRYfk=
-github.com/go-gl/glfw/v3.3/glfw v0.0.0-20210727001814-0db043d8d5be/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
-github.com/go-gl/mathgl v1.0.0 h1:t9DznWJlXxxjeeKLIdovCOVJQk/GzDEL7h/h+Ro2B68=
-github.com/go-gl/mathgl v1.0.0/go.mod h1:yhpkQzEiH9yPyxDUGzkmgScbaBVlhC06qodikEM0ZwQ=
-github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
-github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
-github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
-github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
-github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/image v0.0.0-20190321063152-3fc05d484e9f/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
-golang.org/x/image v0.5.0 h1:5JMiNunQeQw++mMOz48/ISeNu3Iweh/JaZU8ZLqHRrI=
-golang.org/x/image v0.5.0/go.mod h1:FVC7BI/5Ym8R25iw5OLsgshdUBbT1h5jZTpA+mvAdZ4=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
-golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

imdraw/imdraw.go

@@ -52,7 +52,6 @@ type IMDraw struct {
 	EndShape  EndShape
 
 	points []point
-	pool   [][]point
 	matrix pixel.Matrix
 	mask   pixel.RGBA
 
@@ -110,7 +109,7 @@ func (imd *IMDraw) Clear() {
 //
 // This does not affect matrix and color mask set by SetMatrix and SetColorMask.
 func (imd *IMDraw) Reset() {
-	imd.points = imd.points[:0]
+	imd.points = nil
 	imd.Color = pixel.Alpha(1)
 	imd.Picture = pixel.ZV
 	imd.Intensity = 0
@@ -128,11 +127,7 @@ func (imd *IMDraw) Draw(t pixel.Target) {
 // Push adds some points to the IM queue. All Pushed points will have the same properties except for
 // the position.
 func (imd *IMDraw) Push(pts ...pixel.Vec) {
-	// Assert that Color is of type pixel.RGBA,
-	if _, ok := imd.Color.(pixel.RGBA); !ok {
-		// otherwise cast it
-		imd.Color = pixel.ToRGBA(imd.Color)
-	}
+	imd.Color = pixel.ToRGBA(imd.Color)
 	opts := point{
 		col:       imd.Color.(pixel.RGBA),
 		pic:       imd.Picture,
@@ -261,22 +256,10 @@ func (imd *IMDraw) EllipseArc(radius pixel.Vec, low, high, thickness float64) {
 
 func (imd *IMDraw) getAndClearPoints() []point {
 	points := imd.points
-	// use one of the existing pools so we don't reallocate as often
-	if len(imd.pool) > 0 {
-		pos := len(imd.pool) - 1
-		imd.points = imd.pool[pos][:0]
-		imd.pool = imd.pool[:pos]
-	} else {
-		imd.points = nil
-	}
+	imd.points = nil
 	return points
 }
 
-func (imd *IMDraw) restorePoints(points []point) {
-	imd.pool = append(imd.pool, imd.points)
-	imd.points = points[:0]
-}
-
 func (imd *IMDraw) applyMatrixAndMask(off int) {
 	for i := range (*imd.tri)[off:] {
 		(*imd.tri)[off+i].Position = imd.matrix.Project((*imd.tri)[off+i].Position)
@@ -288,7 +271,6 @@ func (imd *IMDraw) fillRectangle() {
 	points := imd.getAndClearPoints()
 
 	if len(points) < 2 {
-		imd.restorePoints(points)
 		return
 	}
 
@@ -310,7 +292,7 @@ func (imd *IMDraw) fillRectangle() {
 			in:  (a.in + b.in) / 2,
 		}
 
-		for k, p := range [...]point{a, b, c, a, b, d} {
+		for k, p := range []point{a, b, c, a, b, d} {
 			(*imd.tri)[j+k].Position = p.pos
 			(*imd.tri)[j+k].Color = p.col
 			(*imd.tri)[j+k].Picture = p.pic
@@ -320,15 +302,12 @@ func (imd *IMDraw) fillRectangle() {
 
 	imd.applyMatrixAndMask(off)
 	imd.batch.Dirty()
-
-	imd.restorePoints(points)
 }
 
 func (imd *IMDraw) outlineRectangle(thickness float64) {
 	points := imd.getAndClearPoints()
 
 	if len(points) < 2 {
-		imd.restorePoints(points)
 		return
 	}
 
@@ -344,15 +323,12 @@ func (imd *IMDraw) outlineRectangle(thickness float64) {
 		imd.pushPt(pixel.V(b.pos.X, a.pos.Y), mid)
 		imd.polyline(thickness, true)
 	}
-
-	imd.restorePoints(points)
 }
 
 func (imd *IMDraw) fillPolygon() {
 	points := imd.getAndClearPoints()
 
 	if len(points) < 3 {
-		imd.restorePoints(points)
 		return
 	}
 
@@ -360,19 +336,16 @@ func (imd *IMDraw) fillPolygon() {
 	imd.tri.SetLen(imd.tri.Len() + 3*(len(points)-2))
 
 	for i, j := 1, off; i+1 < len(points); i, j = i+1, j+3 {
-		for k, p := range [...]int{0, i, i + 1} {
-			tri := &(*imd.tri)[j+k]
-			tri.Position = points[p].pos
-			tri.Color = points[p].col
-			tri.Picture = points[p].pic
-			tri.Intensity = points[p].in
+		for k, p := range []point{points[0], points[i], points[i+1]} {
+			(*imd.tri)[j+k].Position = p.pos
+			(*imd.tri)[j+k].Color = p.col
+			(*imd.tri)[j+k].Picture = p.pic
+			(*imd.tri)[j+k].Intensity = p.in
 		}
 	}
 
 	imd.applyMatrixAndMask(off)
 	imd.batch.Dirty()
-
-	imd.restorePoints(points)
 }
 
 func (imd *IMDraw) fillEllipseArc(radius pixel.Vec, low, high float64) {
@@ -414,8 +387,6 @@ func (imd *IMDraw) fillEllipseArc(radius pixel.Vec, low, high float64) {
 		imd.applyMatrixAndMask(off)
 		imd.batch.Dirty()
 	}
-
-	imd.restorePoints(points)
 }
 
 func (imd *IMDraw) outlineEllipseArc(radius pixel.Vec, low, high, thickness float64, doEndShape bool) {
@@ -499,12 +470,12 @@ func (imd *IMDraw) outlineEllipseArc(radius pixel.Vec, low, high, thickness floa
 				thick := pixel.V(thickness/2, 0).Rotated(normalLow)
 				imd.pushPt(lowCenter.Add(thick), pt)
 				imd.pushPt(lowCenter.Sub(thick), pt)
-				imd.pushPt(lowCenter.Sub(thick.Normal().Scaled(orientation)), pt)
+				imd.pushPt(lowCenter.Sub(thick.Rotated(math.Pi/2*orientation)), pt)
 				imd.fillPolygon()
 				thick = pixel.V(thickness/2, 0).Rotated(normalHigh)
 				imd.pushPt(highCenter.Add(thick), pt)
 				imd.pushPt(highCenter.Sub(thick), pt)
-				imd.pushPt(highCenter.Add(thick.Normal().Scaled(orientation)), pt)
+				imd.pushPt(highCenter.Add(thick.Rotated(math.Pi/2*orientation)), pt)
 				imd.fillPolygon()
 			case RoundEndShape:
 				imd.pushPt(lowCenter, pt)
@@ -514,15 +485,12 @@ func (imd *IMDraw) outlineEllipseArc(radius pixel.Vec, low, high, thickness floa
 			}
 		}
 	}
-
-	imd.restorePoints(points)
 }
 
 func (imd *IMDraw) polyline(thickness float64, closed bool) {
 	points := imd.getAndClearPoints()
 
 	if len(points) == 0 {
-		imd.restorePoints(points)
 		return
 	}
 	if len(points) == 1 {
@@ -532,25 +500,25 @@ func (imd *IMDraw) polyline(thickness float64, closed bool) {
 
 	// first point
 	j, i := 0, 1
-	ijNormal := points[0].pos.To(points[1].pos).Normal().Unit().Scaled(thickness / 2)
+	normal := points[i].pos.Sub(points[j].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
 
 	if !closed {
 		switch points[j].endshape {
 		case NoEndShape:
 			// nothing
 		case SharpEndShape:
-			imd.pushPt(points[j].pos.Add(ijNormal), points[j])
-			imd.pushPt(points[j].pos.Sub(ijNormal), points[j])
-			imd.pushPt(points[j].pos.Add(ijNormal.Normal()), points[j])
+			imd.pushPt(points[j].pos.Add(normal), points[j])
+			imd.pushPt(points[j].pos.Sub(normal), points[j])
+			imd.pushPt(points[j].pos.Add(normal.Rotated(math.Pi/2)), points[j])
 			imd.fillPolygon()
 		case RoundEndShape:
 			imd.pushPt(points[j].pos, points[j])
-			imd.fillEllipseArc(pixel.V(thickness/2, thickness/2), ijNormal.Angle(), ijNormal.Angle()+math.Pi)
+			imd.fillEllipseArc(pixel.V(thickness/2, thickness/2), normal.Angle(), normal.Angle()+math.Pi)
 		}
 	}
 
-	imd.pushPt(points[j].pos.Add(ijNormal), points[j])
-	imd.pushPt(points[j].pos.Sub(ijNormal), points[j])
+	imd.pushPt(points[j].pos.Add(normal), points[j])
+	imd.pushPt(points[j].pos.Sub(normal), points[j])
 
 	// middle points
 	for i := 0; i < len(points); i++ {
@@ -568,7 +536,8 @@ func (imd *IMDraw) polyline(thickness float64, closed bool) {
 			k %= len(points)
 		}
 
-		jkNormal := points[j].pos.To(points[k].pos).Normal().Unit().Scaled(thickness / 2)
+		ijNormal := points[j].pos.Sub(points[i].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
+		jkNormal := points[k].pos.Sub(points[j].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
 
 		orientation := 1.0
 		if ijNormal.Cross(jkNormal) > 0 {
@@ -598,16 +567,14 @@ func (imd *IMDraw) polyline(thickness float64, closed bool) {
 			imd.pushPt(points[j].pos.Add(jkNormal), points[j])
 			imd.pushPt(points[j].pos.Sub(jkNormal), points[j])
 		}
-		// "next" normal becomes previous normal
-		ijNormal = jkNormal
 	}
 
 	// last point
 	i, j = len(points)-2, len(points)-1
-	ijNormal = points[i].pos.To(points[j].pos).Normal().Unit().Scaled(thickness / 2)
+	normal = points[j].pos.Sub(points[i].pos).Rotated(math.Pi / 2).Unit().Scaled(thickness / 2)
 
-	imd.pushPt(points[j].pos.Sub(ijNormal), points[j])
-	imd.pushPt(points[j].pos.Add(ijNormal), points[j])
+	imd.pushPt(points[j].pos.Sub(normal), points[j])
+	imd.pushPt(points[j].pos.Add(normal), points[j])
 	imd.fillPolygon()
 
 	if !closed {
@@ -615,15 +582,13 @@ func (imd *IMDraw) polyline(thickness float64, closed bool) {
 		case NoEndShape:
 			// nothing
 		case SharpEndShape:
-			imd.pushPt(points[j].pos.Add(ijNormal), points[j])
-			imd.pushPt(points[j].pos.Sub(ijNormal), points[j])
-			imd.pushPt(points[j].pos.Add(ijNormal.Normal().Scaled(-1)), points[j])
+			imd.pushPt(points[j].pos.Add(normal), points[j])
+			imd.pushPt(points[j].pos.Sub(normal), points[j])
+			imd.pushPt(points[j].pos.Add(normal.Rotated(-math.Pi/2)), points[j])
 			imd.fillPolygon()
 		case RoundEndShape:
 			imd.pushPt(points[j].pos, points[j])
-			imd.fillEllipseArc(pixel.V(thickness/2, thickness/2), ijNormal.Angle(), ijNormal.Angle()-math.Pi)
+			imd.fillEllipseArc(pixel.V(thickness/2, thickness/2), normal.Angle(), normal.Angle()-math.Pi)
 		}
 	}
-
-	imd.restorePoints(points)
 }

imdraw/imdraw_test.go

@@ -1,96 +0,0 @@
-package imdraw_test
-
-import (
-	"fmt"
-	"math/rand"
-	"testing"
-
-	"github.com/faiface/pixel"
-	"github.com/faiface/pixel/imdraw"
-)
-
-func BenchmarkPush(b *testing.B) {
-	imd := imdraw.New(nil)
-	for i := 0; i < b.N; i++ {
-		imd.Push(pixel.V(123.1, 99.4))
-	}
-}
-
-func pointLists(counts ...int) [][]pixel.Vec {
-	lists := make([][]pixel.Vec, len(counts))
-	for i := range lists {
-		lists[i] = make([]pixel.Vec, counts[i])
-		for j := range lists[i] {
-			lists[i][j] = pixel.V(
-				rand.Float64()*5000-2500,
-				rand.Float64()*5000-2500,
-			)
-		}
-	}
-	return lists
-}
-
-func BenchmarkLine(b *testing.B) {
-	lists := pointLists(2, 5, 10, 100, 1000)
-	for _, pts := range lists {
-		b.Run(fmt.Sprintf("%d", len(pts)), func(b *testing.B) {
-			imd := imdraw.New(nil)
-			for i := 0; i < b.N; i++ {
-				imd.Push(pts...)
-				imd.Line(1)
-			}
-		})
-	}
-}
-
-func BenchmarkRectangle(b *testing.B) {
-	lists := pointLists(2, 10, 100, 1000)
-	for _, pts := range lists {
-		b.Run(fmt.Sprintf("%d", len(pts)), func(b *testing.B) {
-			imd := imdraw.New(nil)
-			for i := 0; i < b.N; i++ {
-				imd.Push(pts...)
-				imd.Rectangle(0)
-			}
-		})
-	}
-}
-
-func BenchmarkPolygon(b *testing.B) {
-	lists := pointLists(3, 10, 100, 1000)
-	for _, pts := range lists {
-		b.Run(fmt.Sprintf("%d", len(pts)), func(b *testing.B) {
-			imd := imdraw.New(nil)
-			for i := 0; i < b.N; i++ {
-				imd.Push(pts...)
-				imd.Polygon(0)
-			}
-		})
-	}
-}
-
-func BenchmarkEllipseFill(b *testing.B) {
-	lists := pointLists(1, 10, 100, 1000)
-	for _, pts := range lists {
-		b.Run(fmt.Sprintf("%d", len(pts)), func(b *testing.B) {
-			imd := imdraw.New(nil)
-			for i := 0; i < b.N; i++ {
-				imd.Push(pts...)
-				imd.Ellipse(pixel.V(50, 100), 0)
-			}
-		})
-	}
-}
-
-func BenchmarkEllipseOutline(b *testing.B) {
-	lists := pointLists(1, 10, 100, 1000)
-	for _, pts := range lists {
-		b.Run(fmt.Sprintf("%d", len(pts)), func(b *testing.B) {
-			imd := imdraw.New(nil)
-			for i := 0; i < b.N; i++ {
-				imd.Push(pts...)
-				imd.Ellipse(pixel.V(50, 100), 1)
-			}
-		})
-	}
-}

interface.go

@@ -92,7 +92,7 @@ type TrianglesColor interface {
 	Color(i int) RGBA
 }
 
-// TrianglesPicture specifies Triangles with Picture property.
+// TrianglesPicture specifies Triangles with Picture propery.
 //
 // The first value returned from Picture method is Picture coordinates. The second one specifies the
 // weight of the Picture. Value of 0 means, that Picture should be completely ignored, 1 means that
@@ -102,19 +102,10 @@ type TrianglesPicture interface {
 	Picture(i int) (pic Vec, intensity float64)
 }
 
-// TrianglesClipped specifies Triangles with Clipping Rectangle property.
-//
-// The first value returned from ClipRect method is the clipping rectangle. The second one specifies
-// if the triangle is clipped.
-type TrianglesClipped interface {
-	Triangles
-	ClipRect(i int) (rect Rect, is bool)
-}
-
 // Picture represents a rectangular area of raster data, such as a color. It has Bounds which
 // specify the rectangle where data is located.
 type Picture interface {
-	// Bounds returns the rectangle of the Picture. All data is located within this rectangle.
+	// Bounds returns the rectangle of the Picture. All data is located witih this rectangle.
 	// Querying properties outside the rectangle should return default value of that property.
 	Bounds() Rect
 }

line_test.go

@@ -1,699 +0,0 @@
-package pixel_test
-
-import (
-	"math"
-	"reflect"
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-func TestLine_Bounds(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   pixel.Rect
-	}{
-		{
-			name:   "Positive slope",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			want:   pixel.R(0, 0, 10, 10),
-		},
-		{
-			name:   "Negative slope",
-			fields: fields{A: pixel.V(10, 10), B: pixel.V(0, 0)},
-			want:   pixel.R(0, 0, 10, 10),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.Bounds(); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.Bounds() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_Center(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   pixel.Vec
-	}{
-		{
-			name:   "Positive slope",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			want:   pixel.V(5, 5),
-		},
-		{
-			name:   "Negative slope",
-			fields: fields{A: pixel.V(10, 10), B: pixel.V(0, 0)},
-			want:   pixel.V(5, 5),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.Center(); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.Center() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_Closest(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		v pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Vec
-	}{
-		{
-			name:   "Point on line",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{v: pixel.V(5, 5)},
-			want:   pixel.V(5, 5),
-		},
-		{
-			name:   "Point on next to line",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{v: pixel.V(0, 10)},
-			want:   pixel.V(5, 5),
-		},
-		{
-			name:   "Point on next to vertical line",
-			fields: fields{A: pixel.V(5, 0), B: pixel.V(5, 10)},
-			args:   args{v: pixel.V(6, 5)},
-			want:   pixel.V(5, 5),
-		},
-		{
-			name:   "Point on next to horizontal line",
-			fields: fields{A: pixel.V(0, 5), B: pixel.V(10, 5)},
-			args:   args{v: pixel.V(5, 6)},
-			want:   pixel.V(5, 5),
-		},
-		{
-			name:   "Point far from line",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{v: pixel.V(80, -70)},
-			want:   pixel.V(5, 5),
-		},
-		{
-			name:   "Point on inline with line",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{v: pixel.V(20, 20)},
-			want:   pixel.V(10, 10),
-		},
-		{
-			name:   "Vertical line",
-			fields: fields{A: pixel.V(0, -10), B: pixel.V(0, 10)},
-			args:   args{v: pixel.V(-1, 0)},
-			want:   pixel.V(0, 0),
-		},
-		{
-			name:   "Horizontal line",
-			fields: fields{A: pixel.V(-10, 0), B: pixel.V(10, 0)},
-			args:   args{v: pixel.V(0, -1)},
-			want:   pixel.V(0, 0),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.Closest(tt.args.v); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.Closest() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_Contains(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		v pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   bool
-	}{
-		{
-			name:   "Point on line",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{v: pixel.V(5, 5)},
-			want:   true,
-		},
-		{
-			name:   "Point on negative sloped line",
-			fields: fields{A: pixel.V(0, 10), B: pixel.V(10, 0)},
-			args:   args{v: pixel.V(5, 5)},
-			want:   true,
-		},
-		{
-			name:   "Point not on line",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{v: pixel.V(0, 10)},
-			want:   false,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.Contains(tt.args.v); got != tt.want {
-				t.Errorf("Line.Contains() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_Formula(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		wantM  float64
-		wantB  float64
-	}{
-		{
-			name:   "Getting formula - 45 degs",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			wantM:  1,
-			wantB:  0,
-		},
-		{
-			name:   "Getting formula - 90 degs",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(0, 10)},
-			wantM:  math.Inf(1),
-			wantB:  math.NaN(),
-		},
-		{
-			name:   "Getting formula - 0 degs",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 0)},
-			wantM:  0,
-			wantB:  0,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			gotM, gotB := l.Formula()
-			if gotM != tt.wantM {
-				t.Errorf("Line.Formula() gotM = %v, want %v", gotM, tt.wantM)
-			}
-			if gotB != tt.wantB {
-				if math.IsNaN(tt.wantB) && !math.IsNaN(gotB) {
-					t.Errorf("Line.Formula() gotB = %v, want %v", gotB, tt.wantB)
-				}
-			}
-		})
-	}
-}
-
-func TestLine_Intersect(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		k pixel.Line
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Vec
-		want1  bool
-	}{
-		{
-			name:   "Lines intersect",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{k: pixel.L(pixel.V(0, 10), pixel.V(10, 0))},
-			want:   pixel.V(5, 5),
-			want1:  true,
-		},
-		{
-			name:   "Lines intersect 2",
-			fields: fields{A: pixel.V(5, 1), B: pixel.V(1, 1)},
-			args:   args{k: pixel.L(pixel.V(2, 0), pixel.V(2, 3))},
-			want:   pixel.V(2, 1),
-			want1:  true,
-		},
-		{
-			name:   "Line intersect with vertical",
-			fields: fields{A: pixel.V(5, 0), B: pixel.V(5, 10)},
-			args:   args{k: pixel.L(pixel.V(0, 0), pixel.V(10, 10))},
-			want:   pixel.V(5, 5),
-			want1:  true,
-		},
-		{
-			name:   "Line intersect with horizontal",
-			fields: fields{A: pixel.V(0, 5), B: pixel.V(10, 5)},
-			args:   args{k: pixel.L(pixel.V(0, 0), pixel.V(10, 10))},
-			want:   pixel.V(5, 5),
-			want1:  true,
-		},
-		{
-			name:   "Lines don't intersect",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{k: pixel.L(pixel.V(0, 10), pixel.V(1, 20))},
-			want:   pixel.ZV,
-			want1:  false,
-		},
-		{
-			name:   "Lines don't intersect 2",
-			fields: fields{A: pixel.V(1, 1), B: pixel.V(1, 5)},
-			args:   args{k: pixel.L(pixel.V(-5, 0), pixel.V(-2, 2))},
-			want:   pixel.ZV,
-			want1:  false,
-		},
-		{
-			name:   "Lines don't intersect 3",
-			fields: fields{A: pixel.V(2, 0), B: pixel.V(2, 3)},
-			args:   args{k: pixel.L(pixel.V(1, 5), pixel.V(5, 5))},
-			want:   pixel.ZV,
-			want1:  false,
-		},
-		{
-			name:   "Lines parallel",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{k: pixel.L(pixel.V(0, 1), pixel.V(10, 11))},
-			want:   pixel.ZV,
-			want1:  false,
-		}, {
-			name:   "Lines intersect",
-			fields: fields{A: pixel.V(600, 600), B: pixel.V(925, 150)},
-			args:   args{k: pixel.L(pixel.V(740, 255), pixel.V(925, 255))},
-			want:   pixel.V(849.1666666666666, 255),
-			want1:  true,
-		},
-		{
-			name:   "Lines intersect",
-			fields: fields{A: pixel.V(600, 600), B: pixel.V(925, 150)},
-			args:   args{k: pixel.L(pixel.V(740, 255), pixel.V(925, 255.0001))},
-			want:   pixel.V(849.1666240490657, 255.000059008986),
-			want1:  true,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			got, got1 := l.Intersect(tt.args.k)
-			if !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.Intersect() got = %v, want %v", got, tt.want)
-			}
-			if got1 != tt.want1 {
-				t.Errorf("Line.Intersect() got1 = %v, want %v", got1, tt.want1)
-			}
-		})
-	}
-}
-
-func TestLine_IntersectCircle(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		c pixel.Circle
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Vec
-	}{
-		{
-			name:   "Cirle intersects",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(6, 4), 2)},
-			want:   pixel.V(0.5857864376269049, -0.5857864376269049),
-		},
-		{
-			name:   "Cirle doesn't intersects",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(0, 5), 1)},
-			want:   pixel.ZV,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.IntersectCircle(tt.args.c); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.IntersectCircle() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_IntersectRect(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		r pixel.Rect
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Vec
-	}{
-		{
-			name:   "Line through rect vertically",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(0, 10)},
-			args:   args{r: pixel.R(-1, 1, 5, 5)},
-			want:   pixel.V(-1, 0),
-		},
-		{
-			name:   "Line through rect horizontally",
-			fields: fields{A: pixel.V(0, 1), B: pixel.V(10, 1)},
-			args:   args{r: pixel.R(1, 0, 5, 5)},
-			want:   pixel.V(0, -1),
-		},
-		{
-			name:   "Line through rect diagonally bottom and left edges",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{r: pixel.R(0, 2, 3, 3)},
-			want:   pixel.V(-1, 1),
-		},
-		{
-			name:   "Line through rect diagonally top and right edges",
-			fields: fields{A: pixel.V(10, 0), B: pixel.V(0, 10)},
-			args:   args{r: pixel.R(5, 0, 8, 3)},
-			want:   pixel.V(-2.5, -2.5),
-		},
-		{
-			name:   "Line with not rect intersect",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{r: pixel.R(20, 20, 21, 21)},
-			want:   pixel.ZV,
-		},
-		{
-			name:   "Line intersects at 0,0",
-			fields: fields{A: pixel.V(0, -10), B: pixel.V(0, 10)},
-			args:   args{r: pixel.R(-1, 0, 2, 2)},
-			want:   pixel.V(-1, 0),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.IntersectRect(tt.args.r); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.IntersectRect() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_Len(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   float64
-	}{
-		{
-			name:   "End right-up of start",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(3, 4)},
-			want:   5,
-		},
-		{
-			name:   "End left-up of start",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(-3, 4)},
-			want:   5,
-		},
-		{
-			name:   "End right-down of start",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(3, -4)},
-			want:   5,
-		},
-		{
-			name:   "End left-down of start",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(-3, -4)},
-			want:   5,
-		},
-		{
-			name:   "End same as start",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(0, 0)},
-			want:   0,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.Len(); got != tt.want {
-				t.Errorf("Line.Len() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_Rotated(t *testing.T) {
-	// round returns the nearest integer, rounding ties away from zero.
-	// This is required because `math.Round` wasn't introduced until Go1.10
-	round := func(x float64) float64 {
-		t := math.Trunc(x)
-		if math.Abs(x-t) >= 0.5 {
-			return t + math.Copysign(1, x)
-		}
-		return t
-	}
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		around pixel.Vec
-		angle  float64
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Line
-	}{
-		{
-			name:   "Rotating around line center",
-			fields: fields{A: pixel.V(1, 1), B: pixel.V(3, 3)},
-			args:   args{around: pixel.V(2, 2), angle: math.Pi},
-			want:   pixel.L(pixel.V(3, 3), pixel.V(1, 1)),
-		},
-		{
-			name:   "Rotating around x-y origin",
-			fields: fields{A: pixel.V(1, 1), B: pixel.V(3, 3)},
-			args:   args{around: pixel.V(0, 0), angle: math.Pi},
-			want:   pixel.L(pixel.V(-1, -1), pixel.V(-3, -3)),
-		},
-		{
-			name:   "Rotating around line end",
-			fields: fields{A: pixel.V(1, 1), B: pixel.V(3, 3)},
-			args:   args{around: pixel.V(1, 1), angle: math.Pi},
-			want:   pixel.L(pixel.V(1, 1), pixel.V(-1, -1)),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			// Have to round the results, due to floating-point in accuracies.  Results are correct to approximately
-			// 10 decimal places.
-			got := l.Rotated(tt.args.around, tt.args.angle)
-			if round(got.A.X) != tt.want.A.X ||
-				round(got.B.X) != tt.want.B.X ||
-				round(got.A.Y) != tt.want.A.Y ||
-				round(got.B.Y) != tt.want.B.Y {
-				t.Errorf("Line.Rotated() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_Scaled(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		scale float64
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Line
-	}{
-		{
-			name:   "Scaling by 1",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{scale: 1},
-			want:   pixel.L(pixel.V(0, 0), pixel.V(10, 10)),
-		},
-		{
-			name:   "Scaling by >1",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{scale: 2},
-			want:   pixel.L(pixel.V(-5, -5), pixel.V(15, 15)),
-		},
-		{
-			name:   "Scaling by <1",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{scale: 0.5},
-			want:   pixel.L(pixel.V(2.5, 2.5), pixel.V(7.5, 7.5)),
-		},
-		{
-			name:   "Scaling by -1",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{scale: -1},
-			want:   pixel.L(pixel.V(10, 10), pixel.V(0, 0)),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.Scaled(tt.args.scale); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.Scaled() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_ScaledXY(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	type args struct {
-		around pixel.Vec
-		scale  float64
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Line
-	}{
-		{
-			name:   "Scaling by 1 around origin",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{around: pixel.ZV, scale: 1},
-			want:   pixel.L(pixel.V(0, 0), pixel.V(10, 10)),
-		},
-		{
-			name:   "Scaling by >1 around origin",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{around: pixel.ZV, scale: 2},
-			want:   pixel.L(pixel.V(0, 0), pixel.V(20, 20)),
-		},
-		{
-			name:   "Scaling by <1 around origin",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{around: pixel.ZV, scale: 0.5},
-			want:   pixel.L(pixel.V(0, 0), pixel.V(5, 5)),
-		},
-		{
-			name:   "Scaling by -1 around origin",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(10, 10)},
-			args:   args{around: pixel.ZV, scale: -1},
-			want:   pixel.L(pixel.V(0, 0), pixel.V(-10, -10)),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.ScaledXY(tt.args.around, tt.args.scale); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Line.ScaledXY() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestLine_String(t *testing.T) {
-	type fields struct {
-		A pixel.Vec
-		B pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   string
-	}{
-		{
-			name:   "Getting string",
-			fields: fields{A: pixel.V(0, 0), B: pixel.V(1, 1)},
-			want:   "Line(Vec(0, 0), Vec(1, 1))",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			l := pixel.Line{
-				A: tt.fields.A,
-				B: tt.fields.B,
-			}
-			if got := l.String(); got != tt.want {
-				t.Errorf("Line.String() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}

math.go

@@ -1,15 +0,0 @@
-package pixel
-
-// Clamp returns x clamped to the interval [min, max].
-//
-// If x is less than min, min is returned. If x is more than max, max is returned. Otherwise, x is
-// returned.
-func Clamp(x, min, max float64) float64 {
-	if x < min {
-		return min
-	}
-	if x > max {
-		return max
-	}
-	return x
-}

math_test.go

@@ -1,46 +0,0 @@
-package pixel_test
-
-import (
-	"fmt"
-	"math"
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-// closeEnough will shift the decimal point by the accuracy required, truncates the results and compares them.
-// Effectively this compares two floats to a given decimal point.
-//  Example:
-//  closeEnough(100.125342432, 100.125, 2) == true
-//  closeEnough(math.Pi, 3.14, 2) == true
-//  closeEnough(0.1234, 0.1245, 3) == false
-func closeEnough(got, expected float64, decimalAccuracy int) bool {
-	gotShifted := got * math.Pow10(decimalAccuracy)
-	expectedShifted := expected * math.Pow10(decimalAccuracy)
-
-	return math.Trunc(gotShifted) == math.Trunc(expectedShifted)
-}
-
-type clampTest struct {
-	number   float64
-	min      float64
-	max      float64
-	expected float64
-}
-
-func TestClamp(t *testing.T) {
-	tests := []clampTest{
-		{number: 1, min: 0, max: 5, expected: 1},
-		{number: 2, min: 0, max: 5, expected: 2},
-		{number: 8, min: 0, max: 5, expected: 5},
-		{number: -5, min: 0, max: 5, expected: 0},
-		{number: -5, min: -4, max: 5, expected: -4},
-	}
-
-	for _, tc := range tests {
-		result := pixel.Clamp(tc.number, tc.min, tc.max)
-		if result != tc.expected {
-			t.Error(fmt.Sprintf("Clamping %v with min %v and max %v should have given %v, but gave %v", tc.number, tc.min, tc.max, tc.expected, result))
-		}
-	}
-}

matrix.go

@@ -1,98 +0,0 @@
-package pixel
-
-import (
-	"fmt"
-	"math"
-)
-
-// Matrix is a 2x3 affine matrix that can be used for all kinds of spatial transforms, such
-// as movement, scaling and rotations.
-//
-// Matrix has a handful of useful methods, each of which adds a transformation to the matrix. For
-// example:
-//
-//   pixel.IM.Moved(pixel.V(100, 200)).Rotated(pixel.ZV, math.Pi/2)
-//
-// This code creates a Matrix that first moves everything by 100 units horizontally and 200 units
-// vertically and then rotates everything by 90 degrees around the origin.
-//
-// Layout is:
-// [0] [2] [4]
-// [1] [3] [5]
-//  0   0   1  (implicit row)
-type Matrix [6]float64
-
-// IM stands for identity matrix. Does nothing, no transformation.
-var IM = Matrix{1, 0, 0, 1, 0, 0}
-
-// String returns a string representation of the Matrix.
-//
-//   m := pixel.IM
-//   fmt.Println(m) // Matrix(1 0 0 | 0 1 0)
-func (m Matrix) String() string {
-	return fmt.Sprintf(
-		"Matrix(%v %v %v | %v %v %v)",
-		m[0], m[2], m[4],
-		m[1], m[3], m[5],
-	)
-}
-
-// Moved moves everything by the delta vector.
-func (m Matrix) Moved(delta Vec) Matrix {
-	m[4], m[5] = m[4]+delta.X, m[5]+delta.Y
-	return m
-}
-
-// ScaledXY scales everything around a given point by the scale factor in each axis respectively.
-func (m Matrix) ScaledXY(around Vec, scale Vec) Matrix {
-	m[4], m[5] = m[4]-around.X, m[5]-around.Y
-	m[0], m[2], m[4] = m[0]*scale.X, m[2]*scale.X, m[4]*scale.X
-	m[1], m[3], m[5] = m[1]*scale.Y, m[3]*scale.Y, m[5]*scale.Y
-	m[4], m[5] = m[4]+around.X, m[5]+around.Y
-	return m
-}
-
-// Scaled scales everything around a given point by the scale factor.
-func (m Matrix) Scaled(around Vec, scale float64) Matrix {
-	return m.ScaledXY(around, V(scale, scale))
-}
-
-// Rotated rotates everything around a given point by the given angle in radians.
-func (m Matrix) Rotated(around Vec, angle float64) Matrix {
-	sint, cost := math.Sincos(angle)
-	m[4], m[5] = m[4]-around.X, m[5]-around.Y
-	m = m.Chained(Matrix{cost, sint, -sint, cost, 0, 0})
-	m[4], m[5] = m[4]+around.X, m[5]+around.Y
-	return m
-}
-
-// Chained adds another Matrix to this one. All tranformations by the next Matrix will be applied
-// after the transformations of this Matrix.
-func (m Matrix) Chained(next Matrix) Matrix {
-	return Matrix{
-		next[0]*m[0] + next[2]*m[1],
-		next[1]*m[0] + next[3]*m[1],
-		next[0]*m[2] + next[2]*m[3],
-		next[1]*m[2] + next[3]*m[3],
-		next[0]*m[4] + next[2]*m[5] + next[4],
-		next[1]*m[4] + next[3]*m[5] + next[5],
-	}
-}
-
-// Project applies all transformations added to the Matrix to a vector u and returns the result.
-//
-// Time complexity is O(1).
-func (m Matrix) Project(u Vec) Vec {
-	return Vec{m[0]*u.X + m[2]*u.Y + m[4], m[1]*u.X + m[3]*u.Y + m[5]}
-}
-
-// Unproject does the inverse operation to Project.
-//
-// Time complexity is O(1).
-func (m Matrix) Unproject(u Vec) Vec {
-	det := m[0]*m[3] - m[2]*m[1]
-	return Vec{
-		(m[3]*(u.X-m[4]) - m[2]*(u.Y-m[5])) / det,
-		(-m[1]*(u.X-m[4]) + m[0]*(u.Y-m[5])) / det,
-	}
-}

matrix_test.go

@@ -1,149 +0,0 @@
-package pixel_test
-
-import (
-	"fmt"
-	"math"
-	"math/rand"
-	"testing"
-
-	"github.com/faiface/pixel"
-	"github.com/stretchr/testify/assert"
-)
-
-func BenchmarkMatrix(b *testing.B) {
-	b.Run("Moved", func(b *testing.B) {
-		m := pixel.IM
-		for i := 0; i < b.N; i++ {
-			m = m.Moved(pixel.V(4.217, -132.99))
-		}
-	})
-	b.Run("ScaledXY", func(b *testing.B) {
-		m := pixel.IM
-		for i := 0; i < b.N; i++ {
-			m = m.ScaledXY(pixel.V(-5.1, 9.3), pixel.V(2.1, 0.98))
-		}
-	})
-	b.Run("Rotated", func(b *testing.B) {
-		m := pixel.IM
-		for i := 0; i < b.N; i++ {
-			m = m.Rotated(pixel.V(-5.1, 9.3), 1.4)
-		}
-	})
-	b.Run("Chained", func(b *testing.B) {
-		var m1, m2 pixel.Matrix
-		for i := range m1 {
-			m1[i] = rand.Float64()
-			m2[i] = rand.Float64()
-		}
-		for i := 0; i < b.N; i++ {
-			m1 = m1.Chained(m2)
-		}
-	})
-	b.Run("Project", func(b *testing.B) {
-		var m pixel.Matrix
-		for i := range m {
-			m[i] = rand.Float64()
-		}
-		u := pixel.V(1, 1)
-		for i := 0; i < b.N; i++ {
-			u = m.Project(u)
-		}
-	})
-	b.Run("Unproject", func(b *testing.B) {
-	again:
-		var m pixel.Matrix
-		for i := range m {
-			m[i] = rand.Float64()
-		}
-		if (m[0]*m[3])-(m[1]*m[2]) == 0 { // zero determinant, not invertible
-			goto again
-		}
-		u := pixel.V(1, 1)
-		for i := 0; i < b.N; i++ {
-			u = m.Unproject(u)
-		}
-	})
-}
-
-func TestMatrix_Unproject(t *testing.T) {
-	const delta = 1e-15
-	t.Run("for rotated matrix", func(t *testing.T) {
-		matrix := pixel.IM.
-			Rotated(pixel.ZV, math.Pi/2)
-		unprojected := matrix.Unproject(pixel.V(0, 1))
-		assert.InDelta(t, unprojected.X, 1, delta)
-		assert.InDelta(t, unprojected.Y, 0, delta)
-	})
-	t.Run("for moved matrix", func(t *testing.T) {
-		matrix := pixel.IM.
-			Moved(pixel.V(1, 2))
-		unprojected := matrix.Unproject(pixel.V(2, 5))
-		assert.InDelta(t, unprojected.X, 1, delta)
-		assert.InDelta(t, unprojected.Y, 3, delta)
-	})
-	t.Run("for scaled matrix", func(t *testing.T) {
-		matrix := pixel.IM.
-			Scaled(pixel.ZV, 2)
-		unprojected := matrix.Unproject(pixel.V(2, 4))
-		assert.InDelta(t, unprojected.X, 1, delta)
-		assert.InDelta(t, unprojected.Y, 2, delta)
-	})
-	t.Run("for scaled, rotated and moved matrix", func(t *testing.T) {
-		matrix := pixel.IM.
-			Scaled(pixel.ZV, 2).
-			Rotated(pixel.ZV, math.Pi/2).
-			Moved(pixel.V(2, 2))
-		unprojected := matrix.Unproject(pixel.V(-2, 6))
-		assert.InDelta(t, unprojected.X, 2, delta)
-		assert.InDelta(t, unprojected.Y, 2, delta)
-	})
-	t.Run("for rotated and moved matrix", func(t *testing.T) {
-		matrix := pixel.IM.
-			Rotated(pixel.ZV, math.Pi/2).
-			Moved(pixel.V(1, 1))
-		unprojected := matrix.Unproject(pixel.V(1, 2))
-		assert.InDelta(t, unprojected.X, 1, delta)
-		assert.InDelta(t, unprojected.Y, 0, delta)
-	})
-	t.Run("for projected vertices using all kinds of matrices", func(t *testing.T) {
-		namedMatrices := map[string]pixel.Matrix{
-			"IM":                        pixel.IM,
-			"Scaled":                    pixel.IM.Scaled(pixel.ZV, 0.5),
-			"Scaled x 2":                pixel.IM.Scaled(pixel.ZV, 2),
-			"Rotated":                   pixel.IM.Rotated(pixel.ZV, math.Pi/4),
-			"Moved":                     pixel.IM.Moved(pixel.V(0.5, 1)),
-			"Moved 2":                   pixel.IM.Moved(pixel.V(-1, -0.5)),
-			"Scaled and Rotated":        pixel.IM.Scaled(pixel.ZV, 0.5).Rotated(pixel.ZV, math.Pi/4),
-			"Scaled, Rotated and Moved": pixel.IM.Scaled(pixel.ZV, 0.5).Rotated(pixel.ZV, math.Pi/4).Moved(pixel.V(1, 2)),
-			"Rotated and Moved":         pixel.IM.Rotated(pixel.ZV, math.Pi/4).Moved(pixel.V(1, 2)),
-		}
-		vertices := [...]pixel.Vec{
-			pixel.V(0, 0),
-			pixel.V(5, 0),
-			pixel.V(5, 10),
-			pixel.V(0, 10),
-			pixel.V(-5, 10),
-			pixel.V(-5, 0),
-			pixel.V(-5, -10),
-			pixel.V(0, -10),
-			pixel.V(5, -10),
-		}
-		for matrixName, matrix := range namedMatrices {
-			for _, vertex := range vertices {
-				testCase := fmt.Sprintf("for matrix %s and vertex %v", matrixName, vertex)
-				t.Run(testCase, func(t *testing.T) {
-					projected := matrix.Project(vertex)
-					unprojected := matrix.Unproject(projected)
-					assert.InDelta(t, vertex.X, unprojected.X, delta)
-					assert.InDelta(t, vertex.Y, unprojected.Y, delta)
-				})
-			}
-		}
-	})
-	t.Run("for singular matrix", func(t *testing.T) {
-		matrix := pixel.Matrix{0, 0, 0, 0, 0, 0}
-		unprojected := matrix.Unproject(pixel.ZV)
-		assert.True(t, math.IsNaN(unprojected.X))
-		assert.True(t, math.IsNaN(unprojected.Y))
-	})
-}

pixel_test.go

@@ -1,68 +0,0 @@
-package pixel_test
-
-import (
-	"bytes"
-	"image"
-	"os"
-	"testing"
-
-	_ "image/png"
-
-	"github.com/faiface/pixel"
-	"github.com/faiface/pixel/pixelgl"
-)
-
-// onePixelImage is the byte representation of a 1x1 solid white png file
-var onePixelImage = []byte{
-	137, 80, 78, 71, 13, 10, 26, 10, 0, 0, 0, 13, 73, 72, 68, 82, 0, 0, 0, 1, 0, 0, 0, 1, 8, 2,
-	0, 0, 0, 144, 119, 83, 222, 0, 0, 1, 130, 105, 67, 67, 80, 73, 67, 67, 32, 112, 114, 111, 102, 105, 108, 101, 0,
-	0, 40, 145, 125, 145, 59, 72, 3, 65, 20, 69, 143, 73, 68, 17, 37, 133, 41, 68, 44, 182, 80, 43, 5, 81, 17, 75,
-	141, 66, 16, 34, 132, 168, 96, 212, 194, 221, 141, 137, 66, 118, 13, 187, 9, 54, 150, 130, 109, 192, 194, 79,
-	227, 175, 176, 177, 214, 214, 194, 86, 16, 4, 63, 32, 54, 182, 86, 138, 54, 18, 214, 55, 73, 32, 65, 140, 3,
-	195, 28, 238, 188, 123, 121, 243, 6, 124, 71, 25, 211, 114, 3, 3, 96, 217, 57, 39, 30, 9, 107, 243, 137, 5, 173,
-	233, 149, 0, 65, 90, 104, 0, 221, 116, 179, 227, 177, 88, 148, 186, 235, 235, 94, 213, 193, 93, 191, 202, 170,
-	95, 247, 231, 106, 75, 174, 184, 38, 52, 104, 194, 99, 102, 214, 201, 9, 47, 11, 143, 108, 228, 178, 138, 247,
-	132, 67, 230, 170, 158, 20, 62, 23, 238, 115, 164, 65, 225, 71, 165, 27, 101, 126, 83, 156, 46, 177, 79, 101,
-	134, 156, 217, 248, 132, 112, 72, 88, 75, 215, 176, 81, 195, 230, 170, 99, 9, 15, 11, 119, 39, 45, 91, 242, 125,
-	243, 101, 78, 42, 222, 84, 108, 101, 242, 102, 165, 79, 245, 194, 214, 21, 123, 110, 70, 233, 178, 187, 136, 48,
-	197, 52, 49, 52, 12, 242, 172, 145, 33, 71, 191, 156, 182, 40, 46, 113, 185, 15, 215, 241, 119, 150, 252, 49,
-	113, 25, 226, 90, 195, 20, 199, 36, 235, 88, 232, 37, 63, 234, 15, 126, 207, 214, 77, 13, 13, 150, 147, 90, 195,
-	208, 248, 226, 121, 31, 61, 208, 180, 3, 197, 130, 231, 125, 31, 123, 94, 241, 4, 252, 207, 112, 101, 87, 253,
-	235, 71, 48, 250, 41, 122, 161, 170, 117, 31, 66, 112, 11, 46, 174, 171, 154, 177, 11, 151, 219, 208, 241, 148,
-	213, 29, 189, 36, 249, 101, 251, 82, 41, 120, 63, 147, 111, 74, 64, 251, 45, 180, 44, 150, 231, 86, 185, 231,
-	244, 1, 102, 101, 86, 209, 27, 216, 63, 128, 222, 180, 100, 47, 213, 121, 119, 115, 237, 220, 254, 173, 169,
-	204, 239, 7, 178, 211, 114, 90, 10, 150, 157, 65, 0, 0, 0, 9, 112, 72, 89, 115, 0, 0, 46, 35, 0, 0, 46, 35, 1,
-	120, 165, 63, 118, 0, 0, 0, 7, 116, 73, 77, 69, 7, 227, 4, 15, 10, 5, 36, 189, 4, 224, 88, 0, 0, 0, 25, 116, 69,
-	88, 116, 67, 111, 109, 109, 101, 110, 116, 0, 67, 114, 101, 97, 116, 101, 100, 32, 119, 105, 116, 104, 32, 71,
-	73, 77, 80, 87, 129, 14, 23, 0, 0, 0, 12, 73, 68, 65, 84, 8, 215, 99, 120, 241, 226, 61, 0, 5, 123, 2, 192, 194,
-	77, 211, 95, 0, 0, 0, 0, 73, 69, 78, 68, 174, 66, 96, 130,
-}
-
-func TestMain(m *testing.M) {
-	pixelgl.Run(func() {
-		os.Exit(m.Run())
-	})
-}
-
-func TestSprite_Draw(t *testing.T) {
-	img, _, err := image.Decode(bytes.NewReader(onePixelImage))
-	if err != nil {
-		t.Fatalf("Could not decode image: %v", err)
-	}
-	pic := pixel.PictureDataFromImage(img)
-
-	sprite := pixel.NewSprite(pic, pic.Bounds())
-
-	cfg := pixelgl.WindowConfig{
-		Title:     "testing",
-		Bounds:    pixel.R(0, 0, 150, 150),
-		Invisible: true,
-	}
-
-	win, err := pixelgl.NewWindow(cfg)
-	if err != nil {
-		t.Fatalf("Could not create window: %v", err)
-	}
-
-	sprite.Draw(win, pixel.IM)
-}

pixelgl/canvas.go

@@ -17,7 +17,7 @@ import (
 // It supports TrianglesPosition, TrianglesColor, TrianglesPicture and PictureColor.
 type Canvas struct {
 	gf     *GLFrame
-	shader *GLShader
+	shader *glhf.Shader
 
 	cmp    pixel.ComposeMethod
 	mat    mgl32.Mat3
@@ -37,35 +37,30 @@ func NewCanvas(bounds pixel.Rect) *Canvas {
 		col: mgl32.Vec4{1, 1, 1, 1},
 	}
 
-	c.shader = NewGLShader(baseCanvasFragmentShader)
 	c.SetBounds(bounds)
+
+	var shader *glhf.Shader
+	mainthread.Call(func() {
+		var err error
+		shader, err = glhf.NewShader(
+			canvasVertexFormat,
+			canvasUniformFormat,
+			canvasVertexShader,
+			canvasFragmentShader,
+		)
+		if err != nil {
+			panic(errors.Wrap(err, "failed to create Canvas, there's a bug in the shader"))
+		}
+	})
+	c.shader = shader
+
 	return c
 }
 
-// SetUniform will update the named uniform with the value of any supported underlying
-// attribute variable. If the uniform already exists, including defaults, they will be reassigned
-// to the new value. The value can be a pointer.
-func (c *Canvas) SetUniform(name string, value interface{}) {
-	c.shader.SetUniform(name, value)
-}
-
-// SetFragmentShader allows you to set a new fragment shader on the underlying
-// framebuffer. Argument "src" is the GLSL source, not a filename.
-func (c *Canvas) SetFragmentShader(src string) {
-	c.shader.fs = src
-	c.shader.Update()
-}
-
 // MakeTriangles creates a specialized copy of the supplied Triangles that draws onto this Canvas.
 //
 // TrianglesPosition, TrianglesColor and TrianglesPicture are supported.
 func (c *Canvas) MakeTriangles(t pixel.Triangles) pixel.TargetTriangles {
-	if gt, ok := t.(*GLTriangles); ok {
-		return &canvasTriangles{
-			GLTriangles: gt,
-			dst:         c,
-		}
-	}
 	return &canvasTriangles{
 		GLTriangles: NewGLTriangles(c.shader, t),
 		dst:         c,
@@ -96,13 +91,8 @@ func (c *Canvas) MakePicture(p pixel.Picture) pixel.TargetPicture {
 
 // SetMatrix sets a Matrix that every point will be projected by.
 func (c *Canvas) SetMatrix(m pixel.Matrix) {
-	// pixel.Matrix is 3x2 with an implicit 0, 0, 1 row after it. So
-	// [0] [2] [4]    [0] [3] [6]
-	// [1] [3] [5] => [1] [4] [7]
-	//  0   0   1      0   0   1
-	// since all matrix ops are affine, the last row never changes, and we don't need to copy it
-	for i, j := range [...]int{0, 1, 3, 4, 6, 7} {
-		c.mat[j] = float32(m[i])
+	for i := range m {
+		c.mat[i] = float32(m[i])
 	}
 }
 
@@ -133,7 +123,7 @@ func (c *Canvas) SetBounds(bounds pixel.Rect) {
 		c.sprite = pixel.NewSprite(nil, pixel.Rect{})
 	}
 	c.sprite.Set(c, c.Bounds())
-	// c.sprite.SetMatrix(pixel.IM.Moved(c.Bounds().Center()))
+	//c.sprite.SetMatrix(pixel.IM.Moved(c.Bounds().Center()))
 }
 
 // Bounds returns the rectangular bounds of the Canvas.
@@ -284,41 +274,29 @@ func (ct *canvasTriangles) draw(tex *glhf.Texture, bounds pixel.Rect) {
 
 	// save the current state vars to avoid race condition
 	cmp := ct.dst.cmp
-	smt := ct.dst.smooth
 	mat := ct.dst.mat
 	col := ct.dst.col
+	smt := ct.dst.smooth
 
 	mainthread.CallNonBlock(func() {
 		ct.dst.setGlhfBounds()
 		setBlendFunc(cmp)
 
 		frame := ct.dst.gf.Frame()
-		shader := ct.shader.s
+		shader := ct.dst.shader
 
 		frame.Begin()
 		shader.Begin()
 
-		ct.shader.uniformDefaults.transform = mat
-		ct.shader.uniformDefaults.colormask = col
 		dstBounds := ct.dst.Bounds()
-		ct.shader.uniformDefaults.bounds = mgl32.Vec4{
+		shader.SetUniformAttr(canvasBounds, mgl32.Vec4{
 			float32(dstBounds.Min.X),
 			float32(dstBounds.Min.Y),
 			float32(dstBounds.W()),
 			float32(dstBounds.H()),
-		}
-
-		bx, by, bw, bh := intBounds(bounds)
-		ct.shader.uniformDefaults.texbounds = mgl32.Vec4{
-			float32(bx),
-			float32(by),
-			float32(bw),
-			float32(bh),
-		}
-
-		for loc, u := range ct.shader.uniforms {
-			ct.shader.s.SetUniformAttr(loc, u.Value())
-		}
+		})
+		shader.SetUniformAttr(canvasTransform, mat)
+		shader.SetUniformAttr(canvasColorMask, col)
 
 		if tex == nil {
 			ct.vs.Begin()
@@ -327,6 +305,14 @@ func (ct *canvasTriangles) draw(tex *glhf.Texture, bounds pixel.Rect) {
 		} else {
 			tex.Begin()
 
+			bx, by, bw, bh := intBounds(bounds)
+			shader.SetUniformAttr(canvasTexBounds, mgl32.Vec4{
+				float32(bx),
+				float32(by),
+				float32(bw),
+				float32(bh),
+			})
+
 			if tex.Smooth() != smt {
 				tex.SetSmooth(smt)
 			}
@@ -359,3 +345,82 @@ func (cp *canvasPicture) Draw(t pixel.TargetTriangles) {
 	}
 	ct.draw(cp.GLPicture.Texture(), cp.GLPicture.Bounds())
 }
+
+const (
+	canvasPosition int = iota
+	canvasColor
+	canvasTexCoords
+	canvasIntensity
+)
+
+var canvasVertexFormat = glhf.AttrFormat{
+	canvasPosition:  {Name: "position", Type: glhf.Vec2},
+	canvasColor:     {Name: "color", Type: glhf.Vec4},
+	canvasTexCoords: {Name: "texCoords", Type: glhf.Vec2},
+	canvasIntensity: {Name: "intensity", Type: glhf.Float},
+}
+
+const (
+	canvasTransform int = iota
+	canvasColorMask
+	canvasBounds
+	canvasTexBounds
+)
+
+var canvasUniformFormat = glhf.AttrFormat{
+	canvasTransform: {Name: "transform", Type: glhf.Mat3},
+	canvasColorMask: {Name: "colorMask", Type: glhf.Vec4},
+	canvasBounds:    {Name: "bounds", Type: glhf.Vec4},
+	canvasTexBounds: {Name: "texBounds", Type: glhf.Vec4},
+}
+
+var canvasVertexShader = `
+#version 330 core
+
+in vec2 position;
+in vec4 color;
+in vec2 texCoords;
+in float intensity;
+
+out vec4 Color;
+out vec2 TexCoords;
+out float Intensity;
+
+uniform mat3 transform;
+uniform vec4 bounds;
+
+void main() {
+	vec2 transPos = (transform * vec3(position, 1.0)).xy;
+	vec2 normPos = (transPos - bounds.xy) / bounds.zw * 2 - vec2(1, 1);
+	gl_Position = vec4(normPos, 0.0, 1.0);
+	Color = color;
+	TexCoords = texCoords;
+	Intensity = intensity;
+}
+`
+
+var canvasFragmentShader = `
+#version 330 core
+
+in vec4 Color;
+in vec2 TexCoords;
+in float Intensity;
+
+out vec4 color;
+
+uniform vec4 colorMask;
+uniform vec4 texBounds;
+uniform sampler2D tex;
+
+void main() {
+	if (Intensity == 0) {
+		color = colorMask * Color;
+	} else {
+		color = vec4(0, 0, 0, 0);
+		color += (1 - Intensity) * Color;
+		vec2 t = (TexCoords - texBounds.xy) / texBounds.zw;
+		color += Intensity * Color * texture(tex, t);
+		color *= colorMask;
+	}
+}
+`

pixelgl/glframe.go

@@ -32,12 +32,6 @@ func (gf *GLFrame) SetBounds(bounds pixel.Rect) {
 		oldF := gf.frame
 
 		_, _, w, h := intBounds(bounds)
-		if w <= 0 {
-			w = 1
-		}
-		if h <= 0 {
-			h = 1
-		}
 		gf.frame = glhf.NewFrame(w, h, false)
 
 		// preserve old content

pixelgl/glshader.go

@@ -1,298 +0,0 @@
-package pixelgl
-
-import (
-	"github.com/faiface/glhf"
-	"github.com/faiface/mainthread"
-	"github.com/go-gl/mathgl/mgl32"
-	"github.com/pkg/errors"
-)
-
-// GLShader is a type to assist with managing a canvas's underlying
-// shader configuration. This allows for customization of shaders on
-// a per canvas basis.
-type GLShader struct {
-	s      *glhf.Shader
-	vf, uf glhf.AttrFormat
-	vs, fs string
-
-	uniforms []gsUniformAttr
-
-	uniformDefaults struct {
-		transform mgl32.Mat3
-		colormask mgl32.Vec4
-		bounds    mgl32.Vec4
-		texbounds mgl32.Vec4
-		cliprect  mgl32.Vec4
-	}
-}
-
-type gsUniformAttr struct {
-	Name      string
-	Type      glhf.AttrType
-	value     interface{}
-	ispointer bool
-}
-
-const (
-	canvasPosition int = iota
-	canvasColor
-	canvasTexCoords
-	canvasIntensity
-	canvasClip
-)
-
-var defaultCanvasVertexFormat = glhf.AttrFormat{
-	canvasPosition:  glhf.Attr{Name: "aPosition", Type: glhf.Vec2},
-	canvasColor:     glhf.Attr{Name: "aColor", Type: glhf.Vec4},
-	canvasTexCoords: glhf.Attr{Name: "aTexCoords", Type: glhf.Vec2},
-	canvasIntensity: glhf.Attr{Name: "aIntensity", Type: glhf.Float},
-  canvasClip:      glhf.Attr{Name: "aClipRect", Type: glhf.Vec4},
-}
-
-// Sets up a base shader with everything needed for a Pixel
-// canvas to render correctly. The defaults can be overridden
-// by simply using the SetUniform function.
-func NewGLShader(fragmentShader string) *GLShader {
-	gs := &GLShader{
-		vf: defaultCanvasVertexFormat,
-		vs: baseCanvasVertexShader,
-		fs: fragmentShader,
-	}
-
-	gs.SetUniform("uTransform", &gs.uniformDefaults.transform)
-	gs.SetUniform("uColorMask", &gs.uniformDefaults.colormask)
-	gs.SetUniform("uBounds", &gs.uniformDefaults.bounds)
-	gs.SetUniform("uTexBounds", &gs.uniformDefaults.texbounds)
-
-	gs.Update()
-
-	return gs
-}
-
-// Update reinitialize GLShader data and recompile the underlying gl shader object
-func (gs *GLShader) Update() {
-	gs.uf = make([]glhf.Attr, len(gs.uniforms))
-	for idx := range gs.uniforms {
-		gs.uf[idx] = glhf.Attr{
-			Name: gs.uniforms[idx].Name,
-			Type: gs.uniforms[idx].Type,
-		}
-	}
-
-	var shader *glhf.Shader
-	mainthread.Call(func() {
-		var err error
-		shader, err = glhf.NewShader(
-			gs.vf,
-			gs.uf,
-			gs.vs,
-			gs.fs,
-		)
-		if err != nil {
-			panic(errors.Wrap(err, "failed to create Canvas, there's a bug in the shader"))
-		}
-	})
-
-	gs.s = shader
-}
-
-// gets the uniform index from GLShader
-func (gs *GLShader) getUniform(Name string) int {
-	for i, u := range gs.uniforms {
-		if u.Name == Name {
-			return i
-		}
-	}
-	return -1
-}
-
-// SetUniform appends a custom uniform name and value to the shader.
-// if the uniform already exists, it will simply be overwritten.
-//
-// example:
-//
-//   utime := float32(time.Since(starttime)).Seconds())
-//   mycanvas.shader.AddUniform("u_time", &utime)
-func (gs *GLShader) SetUniform(name string, value interface{}) {
-	t, p := getAttrType(value)
-	if loc := gs.getUniform(name); loc > -1 {
-		gs.uniforms[loc].Name = name
-		gs.uniforms[loc].Type = t
-		gs.uniforms[loc].ispointer = p
-		gs.uniforms[loc].value = value
-		return
-	}
-	gs.uniforms = append(gs.uniforms, gsUniformAttr{
-		Name:      name,
-		Type:      t,
-		ispointer: p,
-		value:     value,
-	})
-}
-
-// Value returns the attribute's concrete value. If the stored value
-// is a pointer, we return the dereferenced value.
-func (gu *gsUniformAttr) Value() interface{} {
-	if !gu.ispointer {
-		return gu.value
-	}
-	switch gu.Type {
-	case glhf.Vec2:
-		return *gu.value.(*mgl32.Vec2)
-	case glhf.Vec3:
-		return *gu.value.(*mgl32.Vec3)
-	case glhf.Vec4:
-		return *gu.value.(*mgl32.Vec4)
-	case glhf.Mat2:
-		return *gu.value.(*mgl32.Mat2)
-	case glhf.Mat23:
-		return *gu.value.(*mgl32.Mat2x3)
-	case glhf.Mat24:
-		return *gu.value.(*mgl32.Mat2x4)
-	case glhf.Mat3:
-		return *gu.value.(*mgl32.Mat3)
-	case glhf.Mat32:
-		return *gu.value.(*mgl32.Mat3x2)
-	case glhf.Mat34:
-		return *gu.value.(*mgl32.Mat3x4)
-	case glhf.Mat4:
-		return *gu.value.(*mgl32.Mat4)
-	case glhf.Mat42:
-		return *gu.value.(*mgl32.Mat4x2)
-	case glhf.Mat43:
-		return *gu.value.(*mgl32.Mat4x3)
-	case glhf.Int:
-		return *gu.value.(*int32)
-	case glhf.Float:
-		return *gu.value.(*float32)
-	default:
-		panic("invalid attrtype")
-	}
-}
-
-// Returns the type identifier for any (supported) attribute variable type
-// and whether or not it is a pointer of that type.
-func getAttrType(v interface{}) (glhf.AttrType, bool) {
-	switch v.(type) {
-	case int32:
-		return glhf.Int, false
-	case float32:
-		return glhf.Float, false
-	case mgl32.Vec2:
-		return glhf.Vec2, false
-	case mgl32.Vec3:
-		return glhf.Vec3, false
-	case mgl32.Vec4:
-		return glhf.Vec4, false
-	case mgl32.Mat2:
-		return glhf.Mat2, false
-	case mgl32.Mat2x3:
-		return glhf.Mat23, false
-	case mgl32.Mat2x4:
-		return glhf.Mat24, false
-	case mgl32.Mat3:
-		return glhf.Mat3, false
-	case mgl32.Mat3x2:
-		return glhf.Mat32, false
-	case mgl32.Mat3x4:
-		return glhf.Mat34, false
-	case mgl32.Mat4:
-		return glhf.Mat4, false
-	case mgl32.Mat4x2:
-		return glhf.Mat42, false
-	case mgl32.Mat4x3:
-		return glhf.Mat43, false
-	case *mgl32.Vec2:
-		return glhf.Vec2, true
-	case *mgl32.Vec3:
-		return glhf.Vec3, true
-	case *mgl32.Vec4:
-		return glhf.Vec4, true
-	case *mgl32.Mat2:
-		return glhf.Mat2, true
-	case *mgl32.Mat2x3:
-		return glhf.Mat23, true
-	case *mgl32.Mat2x4:
-		return glhf.Mat24, true
-	case *mgl32.Mat3:
-		return glhf.Mat3, true
-	case *mgl32.Mat3x2:
-		return glhf.Mat32, true
-	case *mgl32.Mat3x4:
-		return glhf.Mat34, true
-	case *mgl32.Mat4:
-		return glhf.Mat4, true
-	case *mgl32.Mat4x2:
-		return glhf.Mat42, true
-	case *mgl32.Mat4x3:
-		return glhf.Mat43, true
-	case *int32:
-		return glhf.Int, true
-	case *float32:
-		return glhf.Float, true
-	default:
-		panic("invalid AttrType")
-	}
-}
-
-var baseCanvasVertexShader = `
-#version 330 core
-
-in vec2  aPosition;
-in vec4  aColor;
-in vec2  aTexCoords;
-in float aIntensity;
-in vec4  aClipRect;
-in float aIsClipped;
-
-out vec4  vColor;
-out vec2  vTexCoords;
-out float vIntensity;
-out vec2  vPosition;
-out vec4  vClipRect;
-
-uniform mat3 uTransform;
-uniform vec4 uBounds;
-
-void main() {
-	vec2 transPos = (uTransform * vec3(aPosition, 1.0)).xy;
-	vec2 normPos = (transPos - uBounds.xy) / uBounds.zw * 2 - vec2(1, 1);
-	gl_Position = vec4(normPos, 0.0, 1.0);
-
-	vColor = aColor;
-	vPosition = aPosition;
-	vTexCoords = aTexCoords;
-	vIntensity = aIntensity;
-	vClipRect = aClipRect;
-}
-`
-
-var baseCanvasFragmentShader = `
-#version 330 core
-
-in vec4  vColor;
-in vec2  vTexCoords;
-in float vIntensity;
-in vec4  vClipRect;
-
-out vec4 fragColor;
-
-uniform vec4 uColorMask;
-uniform vec4 uTexBounds;
-uniform sampler2D uTexture;
-
-void main() {
-	if ((vClipRect != vec4(0,0,0,0)) && (gl_FragCoord.x < vClipRect.x || gl_FragCoord.y < vClipRect.y || gl_FragCoord.x > vClipRect.z || gl_FragCoord.y > vClipRect.w))
-		discard;
-
-	if (vIntensity == 0) {
-		fragColor = uColorMask * vColor;
-	} else {
-		fragColor = vec4(0, 0, 0, 0);
-		fragColor += (1 - vIntensity) * vColor;
-		vec2 t = (vTexCoords - uTexBounds.xy) / uTexBounds.zw;
-		fragColor += vIntensity * vColor * texture(uTexture, t);
-		fragColor *= uColorMask;
-	}
-}
-`

pixelgl/gltriangles.go

@@ -15,43 +15,23 @@ import (
 type GLTriangles struct {
 	vs     *glhf.VertexSlice
 	data   []float32
-	shader *GLShader
+	shader *glhf.Shader
 }
 
 var (
 	_ pixel.TrianglesPosition = (*GLTriangles)(nil)
 	_ pixel.TrianglesColor    = (*GLTriangles)(nil)
 	_ pixel.TrianglesPicture  = (*GLTriangles)(nil)
-	_ pixel.TrianglesClipped  = (*GLTriangles)(nil)
-)
-
-// The following is a helper so that the indices of
-// 	each of these items is easier to see/debug.
-const (
-	triPosX = iota
-	triPosY
-	triColorR
-	triColorG
-	triColorB
-	triColorA
-	triPicX
-	triPicY
-	triIntensity
-	triClipMinX
-	triClipMinY
-	triClipMaxX
-	triClipMaxY
-	trisAttrLen
 )
 
 // NewGLTriangles returns GLTriangles initialized with the data from the supplied Triangles.
 //
 // Only draw the Triangles using the provided Shader.
-func NewGLTriangles(shader *GLShader, t pixel.Triangles) *GLTriangles {
+func NewGLTriangles(shader *glhf.Shader, t pixel.Triangles) *GLTriangles {
 	var gt *GLTriangles
 	mainthread.Call(func() {
 		gt = &GLTriangles{
-			vs:     glhf.MakeVertexSlice(shader.s, 0, t.Len()),
+			vs:     glhf.MakeVertexSlice(shader, 0, t.Len()),
 			shader: shader,
 		}
 	})
@@ -68,7 +48,7 @@ func (gt *GLTriangles) VertexSlice() *glhf.VertexSlice {
 }
 
 // Shader returns the GLTriangles's associated shader.
-func (gt *GLTriangles) Shader() *GLShader {
+func (gt *GLTriangles) Shader() *glhf.Shader {
 	return gt.shader
 }
 
@@ -80,29 +60,22 @@ func (gt *GLTriangles) Len() int {
 // SetLen efficiently resizes GLTriangles to len.
 //
 // Time complexity is amortized O(1).
-func (gt *GLTriangles) SetLen(length int) {
-	switch {
-	case length > gt.Len():
-		needAppend := length - gt.Len()
+func (gt *GLTriangles) SetLen(len int) {
+	if len > gt.Len() {
+		needAppend := len - gt.Len()
 		for i := 0; i < needAppend; i++ {
 			gt.data = append(gt.data,
 				0, 0,
 				1, 1, 1, 1,
 				0, 0,
 				0,
-				0, 0, 0, 0,
 			)
 		}
-	case length < gt.Len():
-		gt.data = gt.data[:length*gt.vs.Stride()]
-	default:
-		return
 	}
-	mainthread.Call(func() {
-		gt.vs.Begin()
-		gt.vs.SetLen(length)
-		gt.vs.End()
-	})
+	if len < gt.Len() {
+		gt.data = gt.data[:len*gt.vs.Stride()]
+	}
+	gt.submitData()
 }
 
 // Slice returns a sub-Triangles of this GLTriangles in range [i, j).
@@ -122,67 +95,73 @@ func (gt *GLTriangles) updateData(t pixel.Triangles) {
 	}
 
 	// TrianglesData short path
-	stride := gt.vs.Stride()
-	length := gt.Len()
 	if t, ok := t.(*pixel.TrianglesData); ok {
-		for i := 0; i < length; i++ {
+		for i := 0; i < gt.Len(); i++ {
 			var (
 				px, py = (*t)[i].Position.XY()
 				col    = (*t)[i].Color
 				tx, ty = (*t)[i].Picture.XY()
 				in     = (*t)[i].Intensity
-				rec    = (*t)[i].ClipRect
 			)
-			d := gt.data[i*stride : i*stride+trisAttrLen]
-			d[triPosX] = float32(px)
-			d[triPosY] = float32(py)
-			d[triColorR] = float32(col.R)
-			d[triColorG] = float32(col.G)
-			d[triColorB] = float32(col.B)
-			d[triColorA] = float32(col.A)
-			d[triPicX] = float32(tx)
-			d[triPicY] = float32(ty)
-			d[triIntensity] = float32(in)
-			d[triClipMinX] = float32(rec.Min.X)
-			d[triClipMinY] = float32(rec.Min.Y)
-			d[triClipMaxX] = float32(rec.Max.X)
-			d[triClipMaxY] = float32(rec.Max.Y)
+			gt.data[i*gt.vs.Stride()+0] = float32(px)
+			gt.data[i*gt.vs.Stride()+1] = float32(py)
+			gt.data[i*gt.vs.Stride()+2] = float32(col.R)
+			gt.data[i*gt.vs.Stride()+3] = float32(col.G)
+			gt.data[i*gt.vs.Stride()+4] = float32(col.B)
+			gt.data[i*gt.vs.Stride()+5] = float32(col.A)
+			gt.data[i*gt.vs.Stride()+6] = float32(tx)
+			gt.data[i*gt.vs.Stride()+7] = float32(ty)
+			gt.data[i*gt.vs.Stride()+8] = float32(in)
 		}
 		return
 	}
 
 	if t, ok := t.(pixel.TrianglesPosition); ok {
-		for i := 0; i < length; i++ {
+		for i := 0; i < gt.Len(); i++ {
 			px, py := t.Position(i).XY()
-			gt.data[i*stride+triPosX] = float32(px)
-			gt.data[i*stride+triPosY] = float32(py)
+			gt.data[i*gt.vs.Stride()+0] = float32(px)
+			gt.data[i*gt.vs.Stride()+1] = float32(py)
 		}
 	}
 	if t, ok := t.(pixel.TrianglesColor); ok {
-		for i := 0; i < length; i++ {
+		for i := 0; i < gt.Len(); i++ {
 			col := t.Color(i)
-			gt.data[i*stride+triColorR] = float32(col.R)
-			gt.data[i*stride+triColorG] = float32(col.G)
-			gt.data[i*stride+triColorB] = float32(col.B)
-			gt.data[i*stride+triColorA] = float32(col.A)
+			gt.data[i*gt.vs.Stride()+2] = float32(col.R)
+			gt.data[i*gt.vs.Stride()+3] = float32(col.G)
+			gt.data[i*gt.vs.Stride()+4] = float32(col.B)
+			gt.data[i*gt.vs.Stride()+5] = float32(col.A)
 		}
 	}
 	if t, ok := t.(pixel.TrianglesPicture); ok {
-		for i := 0; i < length; i++ {
+		for i := 0; i < gt.Len(); i++ {
 			pic, intensity := t.Picture(i)
-			gt.data[i*stride+triPicX] = float32(pic.X)
-			gt.data[i*stride+triPicY] = float32(pic.Y)
-			gt.data[i*stride+triIntensity] = float32(intensity)
+			gt.data[i*gt.vs.Stride()+6] = float32(pic.X)
+			gt.data[i*gt.vs.Stride()+7] = float32(pic.Y)
+			gt.data[i*gt.vs.Stride()+8] = float32(intensity)
 		}
 	}
-	if t, ok := t.(pixel.TrianglesClipped); ok {
-		for i := 0; i < length; i++ {
-			rect, _ := t.ClipRect(i)
-			gt.data[i*stride+triClipMinX] = float32(rect.Min.X)
-			gt.data[i*stride+triClipMinY] = float32(rect.Min.Y)
-			gt.data[i*stride+triClipMaxX] = float32(rect.Max.X)
-			gt.data[i*stride+triClipMaxY] = float32(rect.Max.Y)
-		}
+}
+
+func (gt *GLTriangles) submitData() {
+	// this code is supposed to copy the vertex data and CallNonBlock the update if
+	// the data is small enough, otherwise it'll block and not copy the data
+	if len(gt.data) < 256 { // arbitrary heurestic constant
+		data := append([]float32{}, gt.data...)
+		mainthread.CallNonBlock(func() {
+			gt.vs.Begin()
+			dataLen := len(data) / gt.vs.Stride()
+			gt.vs.SetLen(dataLen)
+			gt.vs.SetVertexData(data)
+			gt.vs.End()
+		})
+	} else {
+		mainthread.Call(func() {
+			gt.vs.Begin()
+			dataLen := len(gt.data) / gt.vs.Stride()
+			gt.vs.SetLen(dataLen)
+			gt.vs.SetVertexData(gt.data)
+			gt.vs.End()
+		})
 	}
 }
 
@@ -194,29 +173,7 @@ func (gt *GLTriangles) Update(t pixel.Triangles) {
 		panic(fmt.Errorf("(%T).Update: invalid triangles len", gt))
 	}
 	gt.updateData(t)
-
-	// Copy the verteces down to the glhf.VertexData
-	gt.CopyVertices()
-}
-
-// CopyVertices copies the GLTriangle data down to the vertex data.
-func (gt *GLTriangles) CopyVertices() {
-	// this code is supposed to copy the vertex data and CallNonBlock the update if
-	// the data is small enough, otherwise it'll block and not copy the data
-	if len(gt.data) < 256 { // arbitrary heurestic constant
-		data := append([]float32{}, gt.data...)
-		mainthread.CallNonBlock(func() {
-			gt.vs.Begin()
-			gt.vs.SetVertexData(data)
-			gt.vs.End()
-		})
-	} else {
-		mainthread.Call(func() {
-			gt.vs.Begin()
-			gt.vs.SetVertexData(gt.data)
-			gt.vs.End()
-		})
-	}
+	gt.submitData()
 }
 
 // Copy returns an independent copy of this GLTriangles.
@@ -226,31 +183,19 @@ func (gt *GLTriangles) Copy() pixel.Triangles {
 	return NewGLTriangles(gt.shader, gt)
 }
 
-// index is a helper function that returns the index in the data
-//	slice given the i-th vertex and the item index.
-func (gt *GLTriangles) index(i, idx int) int {
-	return i*gt.vs.Stride() + idx
-}
-
 // Position returns the Position property of the i-th vertex.
 func (gt *GLTriangles) Position(i int) pixel.Vec {
-	px := gt.data[gt.index(i, triPosX)]
-	py := gt.data[gt.index(i, triPosY)]
+	px := gt.data[i*gt.vs.Stride()+0]
+	py := gt.data[i*gt.vs.Stride()+1]
 	return pixel.V(float64(px), float64(py))
 }
 
-// SetPosition sets the position property of the i-th vertex.
-func (gt *GLTriangles) SetPosition(i int, p pixel.Vec) {
-	gt.data[gt.index(i, triPosX)] = float32(p.X)
-	gt.data[gt.index(i, triPosY)] = float32(p.Y)
-}
-
 // Color returns the Color property of the i-th vertex.
 func (gt *GLTriangles) Color(i int) pixel.RGBA {
-	r := gt.data[gt.index(i, triColorR)]
-	g := gt.data[gt.index(i, triColorG)]
-	b := gt.data[gt.index(i, triColorB)]
-	a := gt.data[gt.index(i, triColorA)]
+	r := gt.data[i*gt.vs.Stride()+2]
+	g := gt.data[i*gt.vs.Stride()+3]
+	b := gt.data[i*gt.vs.Stride()+4]
+	a := gt.data[i*gt.vs.Stride()+5]
 	return pixel.RGBA{
 		R: float64(r),
 		G: float64(g),
@@ -259,44 +204,10 @@ func (gt *GLTriangles) Color(i int) pixel.RGBA {
 	}
 }
 
-// SetColor sets the color property of the i-th vertex.
-func (gt *GLTriangles) SetColor(i int, c pixel.RGBA) {
-	gt.data[gt.index(i, triColorR)] = float32(c.R)
-	gt.data[gt.index(i, triColorG)] = float32(c.G)
-	gt.data[gt.index(i, triColorB)] = float32(c.B)
-	gt.data[gt.index(i, triColorA)] = float32(c.A)
-}
-
 // Picture returns the Picture property of the i-th vertex.
 func (gt *GLTriangles) Picture(i int) (pic pixel.Vec, intensity float64) {
-	tx := gt.data[gt.index(i, triPicX)]
-	ty := gt.data[gt.index(i, triPicY)]
-	intensity = float64(gt.data[gt.index(i, triIntensity)])
+	tx := gt.data[i*gt.vs.Stride()+6]
+	ty := gt.data[i*gt.vs.Stride()+7]
+	intensity = float64(gt.data[i*gt.vs.Stride()+8])
 	return pixel.V(float64(tx), float64(ty)), intensity
 }
-
-// SetPicture sets the picture property of the i-th vertex.
-func (gt *GLTriangles) SetPicture(i int, pic pixel.Vec, intensity float64) {
-	gt.data[gt.index(i, triPicX)] = float32(pic.X)
-	gt.data[gt.index(i, triPicY)] = float32(pic.Y)
-	gt.data[gt.index(i, triIntensity)] = float32(intensity)
-}
-
-// ClipRect returns the Clipping rectangle property of the i-th vertex.
-func (gt *GLTriangles) ClipRect(i int) (rect pixel.Rect, is bool) {
-	mx := gt.data[gt.index(i, triClipMinX)]
-	my := gt.data[gt.index(i, triClipMinY)]
-	ax := gt.data[gt.index(i, triClipMaxX)]
-	ay := gt.data[gt.index(i, triClipMaxY)]
-	rect = pixel.R(float64(mx), float64(my), float64(ax), float64(ay))
-	is = rect.Area() != 0.0
-	return
-}
-
-// SetClipRect sets the Clipping rectangle property of the i-th vertex.
-func (gt *GLTriangles) SetClipRect(i int, rect pixel.Rect) {
-	gt.data[gt.index(i, triClipMinX)] = float32(rect.Min.X)
-	gt.data[gt.index(i, triClipMinY)] = float32(rect.Min.Y)
-	gt.data[gt.index(i, triClipMaxX)] = float32(rect.Max.X)
-	gt.data[gt.index(i, triClipMaxY)] = float32(rect.Max.Y)
-}

pixelgl/input.go

@@ -1,11 +1,9 @@
 package pixelgl
 
 import (
-	"time"
-
 	"github.com/faiface/mainthread"
 	"github.com/faiface/pixel"
-	"github.com/go-gl/glfw/v3.3/glfw"
+	"github.com/go-gl/glfw/v3.2/glfw"
 )
 
 // Pressed returns whether the Button is currently pressed down.
@@ -13,14 +11,14 @@ func (w *Window) Pressed(button Button) bool {
 	return w.currInp.buttons[button]
 }
 
-// JustPressed returns whether the Button has been pressed in the last frame.
+// JustPressed returns whether the Button has just been pressed down.
 func (w *Window) JustPressed(button Button) bool {
-	return w.pressEvents[button]
+	return w.currInp.buttons[button] && !w.prevInp.buttons[button]
 }
 
-// JustReleased returns whether the Button has been released in the last frame.
+// JustReleased returns whether the Button has just been released up.
 func (w *Window) JustReleased(button Button) bool {
-	return w.releaseEvents[button]
+	return !w.currInp.buttons[button] && w.prevInp.buttons[button]
 }
 
 // Repeated returns whether a repeat event has been triggered on button.
@@ -35,32 +33,6 @@ func (w *Window) MousePosition() pixel.Vec {
 	return w.currInp.mouse
 }
 
-// MousePreviousPosition returns the previous mouse position in the Window's Bounds.
-func (w *Window) MousePreviousPosition() pixel.Vec {
-	return w.prevInp.mouse
-}
-
-// SetMousePosition positions the mouse cursor anywhere within the Window's Bounds.
-func (w *Window) SetMousePosition(v pixel.Vec) {
-	mainthread.Call(func() {
-		if (v.X >= 0 && v.X <= w.bounds.W()) &&
-			(v.Y >= 0 && v.Y <= w.bounds.H()) {
-			w.window.SetCursorPos(
-				v.X+w.bounds.Min.X,
-				(w.bounds.H()-v.Y)+w.bounds.Min.Y,
-			)
-			w.prevInp.mouse = v
-			w.currInp.mouse = v
-			w.tempInp.mouse = v
-		}
-	})
-}
-
-// MouseInsideWindow returns true if the mouse position is within the Window's Bounds.
-func (w *Window) MouseInsideWindow() bool {
-	return w.cursorInsideWindow
-}
-
 // MouseScroll returns the mouse scroll amount (in both axes) since the last call to Window.Update.
 func (w *Window) MouseScroll() pixel.Vec {
 	return w.currInp.scroll
@@ -362,10 +334,8 @@ func (w *Window) initInput() {
 		w.window.SetMouseButtonCallback(func(_ *glfw.Window, button glfw.MouseButton, action glfw.Action, mod glfw.ModifierKey) {
 			switch action {
 			case glfw.Press:
-				w.tempPressEvents[Button(button)] = true
 				w.tempInp.buttons[Button(button)] = true
 			case glfw.Release:
-				w.tempReleaseEvents[Button(button)] = true
 				w.tempInp.buttons[Button(button)] = false
 			}
 		})
@@ -376,20 +346,14 @@ func (w *Window) initInput() {
 			}
 			switch action {
 			case glfw.Press:
-				w.tempPressEvents[Button(key)] = true
 				w.tempInp.buttons[Button(key)] = true
 			case glfw.Release:
-				w.tempReleaseEvents[Button(key)] = true
 				w.tempInp.buttons[Button(key)] = false
 			case glfw.Repeat:
 				w.tempInp.repeat[Button(key)] = true
 			}
 		})
 
-		w.window.SetCursorEnterCallback(func(_ *glfw.Window, entered bool) {
-			w.cursorInsideWindow = entered
-		})
-
 		w.window.SetCursorPosCallback(func(_ *glfw.Window, x, y float64) {
 			w.tempInp.mouse = pixel.V(
 				x+w.bounds.Min.X,
@@ -408,42 +372,15 @@ func (w *Window) initInput() {
 	})
 }
 
-// UpdateInput polls window events. Call this function to poll window events
-// without swapping buffers. Note that the Update method invokes UpdateInput.
-func (w *Window) UpdateInput() {
+func (w *Window) updateInput() {
 	mainthread.Call(func() {
 		glfw.PollEvents()
 	})
-	w.doUpdateInput()
-}
 
-// UpdateInputWait blocks until an event is received or a timeout. If timeout is 0
-// then it will wait indefinitely
-func (w *Window) UpdateInputWait(timeout time.Duration) {
-	mainthread.Call(func() {
-		if timeout <= 0 {
-			glfw.WaitEvents()
-		} else {
-			glfw.WaitEventsTimeout(timeout.Seconds())
-		}
-	})
-	w.doUpdateInput()
-}
-
-// internal input bookkeeping
-func (w *Window) doUpdateInput() {
 	w.prevInp = w.currInp
 	w.currInp = w.tempInp
 
-	w.pressEvents = w.tempPressEvents
-	w.releaseEvents = w.tempReleaseEvents
-
-	// Clear last frame's temporary status
-	w.tempPressEvents = [KeyLast + 1]bool{}
-	w.tempReleaseEvents = [KeyLast + 1]bool{}
 	w.tempInp.repeat = [KeyLast + 1]bool{}
 	w.tempInp.scroll = pixel.ZV
 	w.tempInp.typed = ""
-
-	w.updateJoystickInput()
 }

pixelgl/joystick.go

@@ -1,193 +0,0 @@
-package pixelgl
-
-import (
-	"github.com/go-gl/glfw/v3.3/glfw"
-)
-
-// Joystick is a joystick or controller (gamepad).
-type Joystick int
-
-// List all of the joysticks.
-const (
-	Joystick1  = Joystick(glfw.Joystick1)
-	Joystick2  = Joystick(glfw.Joystick2)
-	Joystick3  = Joystick(glfw.Joystick3)
-	Joystick4  = Joystick(glfw.Joystick4)
-	Joystick5  = Joystick(glfw.Joystick5)
-	Joystick6  = Joystick(glfw.Joystick6)
-	Joystick7  = Joystick(glfw.Joystick7)
-	Joystick8  = Joystick(glfw.Joystick8)
-	Joystick9  = Joystick(glfw.Joystick9)
-	Joystick10 = Joystick(glfw.Joystick10)
-	Joystick11 = Joystick(glfw.Joystick11)
-	Joystick12 = Joystick(glfw.Joystick12)
-	Joystick13 = Joystick(glfw.Joystick13)
-	Joystick14 = Joystick(glfw.Joystick14)
-	Joystick15 = Joystick(glfw.Joystick15)
-	Joystick16 = Joystick(glfw.Joystick16)
-
-	JoystickLast = Joystick(glfw.JoystickLast)
-)
-
-// GamepadAxis corresponds to a gamepad axis.
-type GamepadAxis int
-
-// Gamepad axis IDs.
-const (
-	AxisLeftX        = GamepadAxis(glfw.AxisLeftX)
-	AxisLeftY        = GamepadAxis(glfw.AxisLeftY)
-	AxisRightX       = GamepadAxis(glfw.AxisRightX)
-	AxisRightY       = GamepadAxis(glfw.AxisRightY)
-	AxisLeftTrigger  = GamepadAxis(glfw.AxisLeftTrigger)
-	AxisRightTrigger = GamepadAxis(glfw.AxisRightTrigger)
-	AxisLast         = GamepadAxis(glfw.AxisLast)
-)
-
-// GamepadButton corresponds to a gamepad button.
-type GamepadButton int
-
-// Gamepad button IDs.
-const (
-	ButtonA           = GamepadButton(glfw.ButtonA)
-	ButtonB           = GamepadButton(glfw.ButtonB)
-	ButtonX           = GamepadButton(glfw.ButtonX)
-	ButtonY           = GamepadButton(glfw.ButtonY)
-	ButtonLeftBumper  = GamepadButton(glfw.ButtonLeftBumper)
-	ButtonRightBumper = GamepadButton(glfw.ButtonRightBumper)
-	ButtonBack        = GamepadButton(glfw.ButtonBack)
-	ButtonStart       = GamepadButton(glfw.ButtonStart)
-	ButtonGuide       = GamepadButton(glfw.ButtonGuide)
-	ButtonLeftThumb   = GamepadButton(glfw.ButtonLeftThumb)
-	ButtonRightThumb  = GamepadButton(glfw.ButtonRightThumb)
-	ButtonDpadUp      = GamepadButton(glfw.ButtonDpadUp)
-	ButtonDpadRight   = GamepadButton(glfw.ButtonDpadRight)
-	ButtonDpadDown    = GamepadButton(glfw.ButtonDpadDown)
-	ButtonDpadLeft    = GamepadButton(glfw.ButtonDpadLeft)
-	ButtonLast        = GamepadButton(glfw.ButtonLast)
-	ButtonCross       = GamepadButton(glfw.ButtonCross)
-	ButtonCircle      = GamepadButton(glfw.ButtonCircle)
-	ButtonSquare      = GamepadButton(glfw.ButtonSquare)
-	ButtonTriangle    = GamepadButton(glfw.ButtonTriangle)
-)
-
-// JoystickPresent returns if the joystick is currently connected.
-//
-// This API is experimental.
-func (w *Window) JoystickPresent(js Joystick) bool {
-	return w.currJoy.connected[js]
-}
-
-// JoystickName returns the name of the joystick. A disconnected joystick will return an
-// empty string.
-//
-// This API is experimental.
-func (w *Window) JoystickName(js Joystick) string {
-	return w.currJoy.name[js]
-}
-
-// JoystickButtonCount returns the number of buttons a connected joystick has.
-//
-// This API is experimental.
-func (w *Window) JoystickButtonCount(js Joystick) int {
-	return len(w.currJoy.buttons[js])
-}
-
-// JoystickAxisCount returns the number of axes a connected joystick has.
-//
-// This API is experimental.
-func (w *Window) JoystickAxisCount(js Joystick) int {
-	return len(w.currJoy.axis[js])
-}
-
-// JoystickPressed returns whether the joystick Button is currently pressed down.
-// If the button index is out of range, this will return false.
-//
-// This API is experimental.
-func (w *Window) JoystickPressed(js Joystick, button GamepadButton) bool {
-	return w.currJoy.getButton(js, int(button))
-}
-
-// JoystickJustPressed returns whether the joystick Button has just been pressed down.
-// If the button index is out of range, this will return false.
-//
-// This API is experimental.
-func (w *Window) JoystickJustPressed(js Joystick, button GamepadButton) bool {
-	return w.currJoy.getButton(js, int(button)) && !w.prevJoy.getButton(js, int(button))
-}
-
-// JoystickJustReleased returns whether the joystick Button has just been released up.
-// If the button index is out of range, this will return false.
-//
-// This API is experimental.
-func (w *Window) JoystickJustReleased(js Joystick, button GamepadButton) bool {
-	return !w.currJoy.getButton(js, int(button)) && w.prevJoy.getButton(js, int(button))
-}
-
-// JoystickAxis returns the value of a joystick axis at the last call to Window.Update.
-// If the axis index is out of range, this will return 0.
-//
-// This API is experimental.
-func (w *Window) JoystickAxis(js Joystick, axis GamepadAxis) float64 {
-	return w.currJoy.getAxis(js, int(axis))
-}
-
-// Used internally during Window.UpdateInput to update the state of the joysticks.
-func (w *Window) updateJoystickInput() {
-	for js := Joystick1; js <= JoystickLast; js++ {
-		// Determine and store if the joystick was connected
-		joystickPresent := glfw.Joystick(js).Present()
-		w.tempJoy.connected[js] = joystickPresent
-
-		if joystickPresent {
-			if glfw.Joystick(js).IsGamepad() {
-				gamepadInputs := glfw.Joystick(js).GetGamepadState()
-
-				w.tempJoy.buttons[js] = gamepadInputs.Buttons[:]
-				w.tempJoy.axis[js] = gamepadInputs.Axes[:]
-			} else {
-				w.tempJoy.buttons[js] = glfw.Joystick(js).GetButtons()
-				w.tempJoy.axis[js] = glfw.Joystick(js).GetAxes()
-			}
-
-			if !w.currJoy.connected[js] {
-				// The joystick was recently connected, we get the name
-				w.tempJoy.name[js] = glfw.Joystick(js).GetName()
-			} else {
-				// Use the name from the previous one
-				w.tempJoy.name[js] = w.currJoy.name[js]
-			}
-		} else {
-			w.tempJoy.buttons[js] = []glfw.Action{}
-			w.tempJoy.axis[js] = []float32{}
-			w.tempJoy.name[js] = ""
-		}
-	}
-
-	w.prevJoy = w.currJoy
-	w.currJoy = w.tempJoy
-}
-
-type joystickState struct {
-	connected [JoystickLast + 1]bool
-	name      [JoystickLast + 1]string
-	buttons   [JoystickLast + 1][]glfw.Action
-	axis      [JoystickLast + 1][]float32
-}
-
-// Returns if a button on a joystick is down, returning false if the button or joystick is invalid.
-func (js *joystickState) getButton(joystick Joystick, button int) bool {
-	// Check that the joystick and button is valid, return false by default
-	if js.buttons[joystick] == nil || button >= len(js.buttons[joystick]) || button < 0 {
-		return false
-	}
-	return js.buttons[joystick][byte(button)] == glfw.Press
-}
-
-// Returns the value of a joystick axis, returning 0 if the button or joystick is invalid.
-func (js *joystickState) getAxis(joystick Joystick, axis int) float64 {
-	// Check that the joystick and axis is valid, return 0 by default.
-	if js.axis[joystick] == nil || axis >= len(js.axis[joystick]) || axis < 0 {
-		return 0
-	}
-	return float64(js.axis[joystick][axis])
-}

pixelgl/monitor.go

@@ -2,7 +2,7 @@ package pixelgl
 
 import (
 	"github.com/faiface/mainthread"
-	"github.com/go-gl/glfw/v3.3/glfw"
+	"github.com/go-gl/glfw/v3.2/glfw"
 )
 
 // Monitor represents a physical display attached to your computer.
@@ -10,17 +10,6 @@ type Monitor struct {
 	monitor *glfw.Monitor
 }
 
-// VideoMode represents all properties of a video mode and is
-// associated with a monitor if it is used in fullscreen mode.
-type VideoMode struct {
-	// Width is the width of the vide mode in pixels.
-	Width int
-	// Height is the height of the video mode in pixels.
-	Height int
-	// RefreshRate holds the refresh rate of the associated monitor in Hz.
-	RefreshRate int
-}
-
 // PrimaryMonitor returns the main monitor (usually the one with the taskbar and stuff).
 func PrimaryMonitor() *Monitor {
 	var monitor *glfw.Monitor
@@ -106,19 +95,3 @@ func (m *Monitor) RefreshRate() (rate float64) {
 	rate = float64(mode.RefreshRate)
 	return
 }
-
-// VideoModes returns all available video modes for the monitor.
-func (m *Monitor) VideoModes() (vmodes []VideoMode) {
-	var modes []*glfw.VidMode
-	mainthread.Call(func() {
-		modes = m.monitor.GetVideoModes()
-	})
-	for _, mode := range modes {
-		vmodes = append(vmodes, VideoMode{
-			Width:       mode.Width,
-			Height:      mode.Height,
-			RefreshRate: mode.RefreshRate,
-		})
-	}
-	return
-}

pixelgl/run.go

@@ -2,7 +2,7 @@ package pixelgl
 
 import (
 	"github.com/faiface/mainthread"
-	"github.com/go-gl/glfw/v3.3/glfw"
+	"github.com/go-gl/glfw/v3.2/glfw"
 	"github.com/pkg/errors"
 )
 

pixelgl/window.go

@@ -1,7 +1,6 @@
 package pixelgl
 
 import (
-	"fmt"
 	"image"
 	"image/color"
 	"runtime"
@@ -9,8 +8,7 @@ import (
 	"github.com/faiface/glhf"
 	"github.com/faiface/mainthread"
 	"github.com/faiface/pixel"
-	"github.com/go-gl/gl/v3.3-core/gl"
-	"github.com/go-gl/glfw/v3.3/glfw"
+	"github.com/go-gl/glfw/v3.2/glfw"
 	"github.com/pkg/errors"
 )
 
@@ -38,59 +36,29 @@ type WindowConfig struct {
 	// Bounds specify the bounds of the Window in pixels.
 	Bounds pixel.Rect
 
-	// Initial window position
-	Position pixel.Vec
-
 	// If set to nil, the Window will be windowed. Otherwise it will be fullscreen on the
 	// specified Monitor.
 	Monitor *Monitor
 
-	// Resizable specifies whether the window will be resizable by the user.
+	// Whether the Window is resizable.
 	Resizable bool
 
-	// Undecorated Window omits the borders and decorations (close button, etc.).
+	// Undecorated Window ommits the borders and decorations (close button, etc.).
 	Undecorated bool
 
-	// NoIconify specifies whether fullscreen windows should not automatically
-	// iconify (and restore the previous video mode) on focus loss.
-	NoIconify bool
-
-	// AlwaysOnTop specifies whether the windowed mode window will be floating
-	// above other regular windows, also called topmost or always-on-top.
-	// This is intended primarily for debugging purposes and cannot be used to
-	// implement proper full screen windows.
-	AlwaysOnTop bool
-
-	// TransparentFramebuffer specifies whether the window framebuffer will be
-	// transparent. If enabled and supported by the system, the window
-	// framebuffer alpha channel will be used to combine the framebuffer with
-	// the background. This does not affect window decorations.
-	TransparentFramebuffer bool
-
 	// VSync (vertical synchronization) synchronizes Window's framerate with the framerate of
 	// the monitor.
 	VSync bool
-
-	// Maximized specifies whether the window is maximized.
-	Maximized bool
-
-	// Invisible specifies whether the window will be initially hidden.
-	// You can make the window visible later using Window.Show().
-	Invisible bool
-
-	//SamplesMSAA specifies the level of MSAA to be used. Must be one of 0, 2, 4, 8, 16. 0 to disable.
-	SamplesMSAA int
 }
 
 // Window is a window handler. Use this type to manipulate a window (input, drawing, etc.).
 type Window struct {
 	window *glfw.Window
 
-	bounds             pixel.Rect
-	canvas             *Canvas
-	vsync              bool
-	cursorVisible      bool
-	cursorInsideWindow bool
+	bounds        pixel.Rect
+	canvas        *Canvas
+	vsync         bool
+	cursorVisible bool
 
 	// need to save these to correctly restore a fullscreen window
 	restore struct {
@@ -104,11 +72,6 @@ type Window struct {
 		scroll  pixel.Vec
 		typed   string
 	}
-
-	pressEvents, tempPressEvents     [KeyLast + 1]bool
-	releaseEvents, tempReleaseEvents [KeyLast + 1]bool
-
-	prevJoy, currJoy, tempJoy joystickState
 }
 
 var currWin *Window
@@ -124,17 +87,6 @@ func NewWindow(cfg WindowConfig) (*Window, error) {
 
 	w := &Window{bounds: cfg.Bounds, cursorVisible: true}
 
-	flag := false
-	for _, v := range []int{0, 2, 4, 8, 16} {
-		if cfg.SamplesMSAA == v {
-			flag = true
-			break
-		}
-	}
-	if !flag {
-		return nil, fmt.Errorf("invalid value '%v' for msaaSamples", cfg.SamplesMSAA)
-	}
-
 	err := mainthread.CallErr(func() error {
 		var err error
 
@@ -145,16 +97,6 @@ func NewWindow(cfg WindowConfig) (*Window, error) {
 
 		glfw.WindowHint(glfw.Resizable, bool2int[cfg.Resizable])
 		glfw.WindowHint(glfw.Decorated, bool2int[!cfg.Undecorated])
-		glfw.WindowHint(glfw.Floating, bool2int[cfg.AlwaysOnTop])
-		glfw.WindowHint(glfw.AutoIconify, bool2int[!cfg.NoIconify])
-		glfw.WindowHint(glfw.TransparentFramebuffer, bool2int[cfg.TransparentFramebuffer])
-		glfw.WindowHint(glfw.Maximized, bool2int[cfg.Maximized])
-		glfw.WindowHint(glfw.Visible, bool2int[!cfg.Invisible])
-		glfw.WindowHint(glfw.Samples, cfg.SamplesMSAA)
-
-		if cfg.Position.X != 0 || cfg.Position.Y != 0 {
-			glfw.WindowHint(glfw.Visible, glfw.False)
-		}
 
 		var share *glfw.Window
 		if currWin != nil {
@@ -172,15 +114,8 @@ func NewWindow(cfg WindowConfig) (*Window, error) {
 			return err
 		}
 
-		if cfg.Position.X != 0 || cfg.Position.Y != 0 {
-			w.window.SetPos(int(cfg.Position.X), int(cfg.Position.Y))
-			w.window.Show()
-		}
-
 		// enter the OpenGL context
 		w.begin()
-		glhf.Init()
-		gl.Enable(gl.MULTISAMPLE)
 		w.end()
 
 		return nil
@@ -222,24 +157,6 @@ func (w *Window) Destroy() {
 
 // Update swaps buffers and polls events. Call this method at the end of each frame.
 func (w *Window) Update() {
-	w.SwapBuffers()
-	w.UpdateInput()
-}
-
-// ClipboardText returns the current value of the systems clipboard.
-func (w *Window) ClipboardText() string {
-	return w.window.GetClipboardString()
-}
-
-// SetClipboardText passes the given string to the underlying glfw window to set the
-//	systems clipboard.
-func (w *Window) SetClipboardText(text string) {
-	w.window.SetClipboardString(text)
-}
-
-// SwapBuffers swaps buffers. Call this to swap buffers without polling window events.
-// Note that Update invokes SwapBuffers.
-func (w *Window) SwapBuffers() {
 	mainthread.Call(func() {
 		_, _, oldW, oldH := intBounds(w.bounds)
 		newW, newH := w.window.GetSize()
@@ -274,6 +191,8 @@ func (w *Window) SwapBuffers() {
 		w.window.SwapBuffers()
 		w.end()
 	})
+
+	w.updateInput()
 }
 
 // SetClosed sets the closed flag of the Window.
@@ -314,29 +233,6 @@ func (w *Window) SetBounds(bounds pixel.Rect) {
 	})
 }
 
-// SetPos sets the position, in screen coordinates, of the upper-left corner
-// of the client area of the window. Position can be fractional, but the actual position
-// of the window will be rounded to integers.
-//
-// If it is a full screen window, this function does nothing.
-func (w *Window) SetPos(pos pixel.Vec) {
-	mainthread.Call(func() {
-		left, top := int(pos.X), int(pos.Y)
-		w.window.SetPos(left, top)
-	})
-}
-
-// GetPos gets the position, in screen coordinates, of the upper-left corner
-// of the client area of the window. The position is rounded to integers.
-func (w *Window) GetPos() pixel.Vec {
-	var v pixel.Vec
-	mainthread.Call(func() {
-		x, y := w.window.GetPos()
-		v = pixel.V(float64(x), float64(y))
-	})
-	return v
-}
-
 // Bounds returns the current bounds of the Window.
 func (w *Window) Bounds() pixel.Rect {
 	return w.bounds
@@ -434,15 +330,6 @@ func (w *Window) SetCursorVisible(visible bool) {
 	})
 }
 
-// SetCursorDisabled hides the cursor and provides unlimited virtual cursor movement
-// make cursor visible using SetCursorVisible
-func (w *Window) SetCursorDisabled() {
-	w.cursorVisible = false
-	mainthread.Call(func() {
-		w.window.SetInputMode(glfw.CursorMode, glfw.CursorDisabled)
-	})
-}
-
 // CursorVisible returns the visibility status of the mouse cursor.
 func (w *Window) CursorVisible() bool {
 	return w.cursorVisible
@@ -452,6 +339,7 @@ func (w *Window) CursorVisible() bool {
 func (w *Window) begin() {
 	if currWin != w {
 		w.window.MakeContextCurrent()
+		glhf.Init()
 		currWin = w
 	}
 }
@@ -513,32 +401,3 @@ func (w *Window) Clear(c color.Color) {
 func (w *Window) Color(at pixel.Vec) pixel.RGBA {
 	return w.canvas.Color(at)
 }
-
-// Canvas returns the window's underlying Canvas
-func (w *Window) Canvas() *Canvas {
-	return w.canvas
-}
-
-// Show makes the window visible, if it was previously hidden. If the window is
-// already visible or is in full screen mode, this function does nothing.
-func (w *Window) Show() {
-	mainthread.Call(func() {
-		w.window.Show()
-	})
-}
-
-// Clipboard returns the contents of the system clipboard.
-func (w *Window) Clipboard() string {
-	var clipboard string
-	mainthread.Call(func() {
-		clipboard = w.window.GetClipboardString()
-	})
-	return clipboard
-}
-
-// SetClipboardString sets the system clipboard to the specified UTF-8 encoded string.
-func (w *Window) SetClipboard(str string) {
-	mainthread.Call(func() {
-		w.window.SetClipboardString(str)
-	})
-}

rectangle.go

@@ -1,284 +0,0 @@
-package pixel
-
-import (
-	"fmt"
-	"math"
-)
-
-// Rect is a 2D rectangle aligned with the axes of the coordinate system. It is defined by two
-// points, Min and Max.
-//
-// The invariant should hold, that Max's components are greater or equal than Min's components
-// respectively.
-type Rect struct {
-	Min, Max Vec
-}
-
-// ZR is a zero rectangle.
-var ZR = Rect{Min: ZV, Max: ZV}
-
-// R returns a new Rect with given the Min and Max coordinates.
-//
-// Note that the returned rectangle is not automatically normalized.
-func R(minX, minY, maxX, maxY float64) Rect {
-	return Rect{
-		Min: Vec{minX, minY},
-		Max: Vec{maxX, maxY},
-	}
-}
-
-// String returns the string representation of the Rect.
-//
-//   r := pixel.R(100, 50, 200, 300)
-//   r.String()     // returns "Rect(100, 50, 200, 300)"
-//   fmt.Println(r) // Rect(100, 50, 200, 300)
-func (r Rect) String() string {
-	return fmt.Sprintf("Rect(%v, %v, %v, %v)", r.Min.X, r.Min.Y, r.Max.X, r.Max.Y)
-}
-
-// Norm returns the Rect in normal form, such that Max is component-wise greater or equal than Min.
-func (r Rect) Norm() Rect {
-	return Rect{
-		Min: Vec{
-			math.Min(r.Min.X, r.Max.X),
-			math.Min(r.Min.Y, r.Max.Y),
-		},
-		Max: Vec{
-			math.Max(r.Min.X, r.Max.X),
-			math.Max(r.Min.Y, r.Max.Y),
-		},
-	}
-}
-
-// W returns the width of the Rect.
-func (r Rect) W() float64 {
-	return r.Max.X - r.Min.X
-}
-
-// H returns the height of the Rect.
-func (r Rect) H() float64 {
-	return r.Max.Y - r.Min.Y
-}
-
-// Size returns the vector of width and height of the Rect.
-func (r Rect) Size() Vec {
-	return V(r.W(), r.H())
-}
-
-// Area returns the area of r. If r is not normalized, area may be negative.
-func (r Rect) Area() float64 {
-	return r.W() * r.H()
-}
-
-// Edges will return the four lines which make up the edges of the rectangle.
-func (r Rect) Edges() [4]Line {
-	corners := r.Vertices()
-
-	return [4]Line{
-		{A: corners[0], B: corners[1]},
-		{A: corners[1], B: corners[2]},
-		{A: corners[2], B: corners[3]},
-		{A: corners[3], B: corners[0]},
-	}
-}
-
-// Anchor is a vector used to define anchors, such as `Center`, `Top`, `TopRight`, etc.
-type Anchor Vec
-
-var (
-	Center      = Anchor{0.5, 0.5}
-	Top         = Anchor{0.5, 0}
-	TopRight    = Anchor{0, 0}
-	Right       = Anchor{0, 0.5}
-	BottomRight = Anchor{0, 1}
-	Bottom      = Anchor{0.5, 1}
-	BottomLeft  = Anchor{1, 1}
-	Left        = Anchor{1, 0.5}
-	TopLeft     = Anchor{1, 0}
-)
-
-var anchorStrings map[Anchor]string = map[Anchor]string{
-	Center:      "center",
-	Top:         "top",
-	TopRight:    "top-right",
-	Right:       "right",
-	BottomRight: "bottom-right",
-	Bottom:      "bottom",
-	BottomLeft:  "bottom-left",
-	Left:        "left",
-	TopLeft:     "top-left",
-}
-
-// String returns the string representation of an anchor.
-func (anchor Anchor) String() string {
-	return anchorStrings[anchor]
-}
-
-var oppositeAnchors map[Anchor]Anchor = map[Anchor]Anchor{
-	Center:      Center,
-	Top:         Bottom,
-	Bottom:      Top,
-	Right:       Left,
-	Left:        Right,
-	TopRight:    BottomLeft,
-	BottomLeft:  TopRight,
-	BottomRight: TopLeft,
-	TopLeft:     BottomRight,
-}
-
-// Opposite returns the opposite position of the anchor (ie. Top -> Bottom; BottomLeft -> TopRight, etc.).
-func (anchor Anchor) Opposite() Anchor {
-	return oppositeAnchors[anchor]
-}
-
-// AnchorPos returns the relative position of the given anchor.
-func (r Rect) AnchorPos(anchor Anchor) Vec {
-	return r.Size().ScaledXY(V(0, 0).Sub(Vec(anchor)))
-}
-
-// AlignedTo returns the rect moved by the given anchor.
-func (rect Rect) AlignedTo(anchor Anchor) Rect {
-	return rect.Moved(rect.AnchorPos(anchor))
-}
-
-// Center returns the position of the center of the Rect.
-// `rect.Center()` is equivalent to `rect.Anchor(pixel.Anchor.Center)`
-func (r Rect) Center() Vec {
-	return Lerp(r.Min, r.Max, 0.5)
-}
-
-// Moved returns the Rect moved (both Min and Max) by the given vector delta.
-func (r Rect) Moved(delta Vec) Rect {
-	return Rect{
-		Min: r.Min.Add(delta),
-		Max: r.Max.Add(delta),
-	}
-}
-
-// Resized returns the Rect resized to the given size while keeping the position of the given
-// anchor.
-//
-//   r.Resized(r.Min, size)      // resizes while keeping the position of the lower-left corner
-//   r.Resized(r.Max, size)      // same with the top-right corner
-//   r.Resized(r.Center(), size) // resizes around the center
-//
-// This function does not make sense for resizing a rectangle of zero area and will panic. Use
-// ResizedMin in the case of zero area.
-func (r Rect) Resized(anchor, size Vec) Rect {
-	if r.W()*r.H() == 0 {
-		panic(fmt.Errorf("(%T).Resize: zero area", r))
-	}
-	fraction := Vec{size.X / r.W(), size.Y / r.H()}
-	return Rect{
-		Min: anchor.Add(r.Min.Sub(anchor).ScaledXY(fraction)),
-		Max: anchor.Add(r.Max.Sub(anchor).ScaledXY(fraction)),
-	}
-}
-
-// ResizedMin returns the Rect resized to the given size while keeping the position of the Rect's
-// Min.
-//
-// Sizes of zero area are safe here.
-func (r Rect) ResizedMin(size Vec) Rect {
-	return Rect{
-		Min: r.Min,
-		Max: r.Min.Add(size),
-	}
-}
-
-// Contains checks whether a vector u is contained within this Rect (including it's borders).
-func (r Rect) Contains(u Vec) bool {
-	return r.Min.X <= u.X && u.X <= r.Max.X && r.Min.Y <= u.Y && u.Y <= r.Max.Y
-}
-
-// Union returns the minimal Rect which covers both r and s. Rects r and s must be normalized.
-func (r Rect) Union(s Rect) Rect {
-	return R(
-		math.Min(r.Min.X, s.Min.X),
-		math.Min(r.Min.Y, s.Min.Y),
-		math.Max(r.Max.X, s.Max.X),
-		math.Max(r.Max.Y, s.Max.Y),
-	)
-}
-
-// Intersect returns the maximal Rect which is covered by both r and s. Rects r and s must be normalized.
-//
-// If r and s don't overlap, this function returns a zero-rectangle.
-func (r Rect) Intersect(s Rect) Rect {
-	t := R(
-		math.Max(r.Min.X, s.Min.X),
-		math.Max(r.Min.Y, s.Min.Y),
-		math.Min(r.Max.X, s.Max.X),
-		math.Min(r.Max.Y, s.Max.Y),
-	)
-	if t.Min.X >= t.Max.X || t.Min.Y >= t.Max.Y {
-		return ZR
-	}
-	return t
-}
-
-// Intersects returns whether or not the given Rect intersects at any point with this Rect.
-//
-// This function is overall about 5x faster than Intersect, so it is better
-// to use if you have no need for the returned Rect from Intersect.
-func (r Rect) Intersects(s Rect) bool {
-	return !(s.Max.X <= r.Min.X ||
-		s.Min.X >= r.Max.X ||
-		s.Max.Y <= r.Min.Y ||
-		s.Min.Y >= r.Max.Y)
-}
-
-// IntersectCircle returns a minimal required Vector, such that moving the rect by that vector would stop the Circle
-// and the Rect intersecting.  This function returns a zero-vector if the Circle and Rect do not overlap, and if only
-// the perimeters touch.
-//
-// This function will return a non-zero vector if:
-//  - The Rect contains the Circle, partially or fully
-//  - The Circle contains the Rect, partially of fully
-func (r Rect) IntersectCircle(c Circle) Vec {
-	return c.IntersectRect(r).Scaled(-1)
-}
-
-// IntersectLine will return the shortest Vec such that if the Rect is moved by the Vec returned, the Line and Rect no
-// longer intersect.
-func (r Rect) IntersectLine(l Line) Vec {
-	return l.IntersectRect(r).Scaled(-1)
-}
-
-// IntersectionPoints returns all the points where the Rect intersects with the line provided.  This can be zero, one or
-// two points, depending on the location of the shapes.  The points of intersection will be returned in order of
-// closest-to-l.A to closest-to-l.B.
-func (r Rect) IntersectionPoints(l Line) []Vec {
-	// Use map keys to ensure unique points
-	pointMap := make(map[Vec]struct{})
-
-	for _, edge := range r.Edges() {
-		if intersect, ok := l.Intersect(edge); ok {
-			pointMap[intersect] = struct{}{}
-		}
-	}
-
-	points := make([]Vec, 0, len(pointMap))
-	for point := range pointMap {
-		points = append(points, point)
-	}
-
-	// Order the points
-	if len(points) == 2 {
-		if points[1].To(l.A).Len() < points[0].To(l.A).Len() {
-			return []Vec{points[1], points[0]}
-		}
-	}
-
-	return points
-}
-
-// Vertices returns a slice of the four corners which make up the rectangle.
-func (r Rect) Vertices() [4]Vec {
-	return [4]Vec{
-		r.Min,
-		V(r.Min.X, r.Max.Y),
-		r.Max,
-		V(r.Max.X, r.Min.Y),
-	}
-}

rectangle_test.go

@@ -1,384 +0,0 @@
-package pixel_test
-
-import (
-	"fmt"
-	"reflect"
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-func TestRect_Resize(t *testing.T) {
-	type rectTestTransform struct {
-		name string
-		f    func(pixel.Rect) pixel.Rect
-	}
-
-	// rectangles
-	squareAroundOrigin := pixel.R(-10, -10, 10, 10)
-	squareAround2020 := pixel.R(10, 10, 30, 30)
-	rectangleAroundOrigin := pixel.R(-20, -10, 20, 10)
-	rectangleAround2020 := pixel.R(0, 10, 40, 30)
-
-	// resize transformations
-	resizeByHalfAroundCenter := rectTestTransform{"by half around center", func(rect pixel.Rect) pixel.Rect {
-		return rect.Resized(rect.Center(), rect.Size().Scaled(0.5))
-	}}
-	resizeByHalfAroundMin := rectTestTransform{"by half around Min", func(rect pixel.Rect) pixel.Rect {
-		return rect.Resized(rect.Min, rect.Size().Scaled(0.5))
-	}}
-	resizeByHalfAroundMax := rectTestTransform{"by half around Max", func(rect pixel.Rect) pixel.Rect {
-		return rect.Resized(rect.Max, rect.Size().Scaled(0.5))
-	}}
-	resizeByHalfAroundMiddleOfLeftSide := rectTestTransform{"by half around middle of left side", func(rect pixel.Rect) pixel.Rect {
-		return rect.Resized(pixel.V(rect.Min.X, rect.Center().Y), rect.Size().Scaled(0.5))
-	}}
-	resizeByHalfAroundOrigin := rectTestTransform{"by half around the origin", func(rect pixel.Rect) pixel.Rect {
-		return rect.Resized(pixel.ZV, rect.Size().Scaled(0.5))
-	}}
-
-	testCases := []struct {
-		input     pixel.Rect
-		transform rectTestTransform
-		answer    pixel.Rect
-	}{
-		{squareAroundOrigin, resizeByHalfAroundCenter, pixel.R(-5, -5, 5, 5)},
-		{squareAround2020, resizeByHalfAroundCenter, pixel.R(15, 15, 25, 25)},
-		{rectangleAroundOrigin, resizeByHalfAroundCenter, pixel.R(-10, -5, 10, 5)},
-		{rectangleAround2020, resizeByHalfAroundCenter, pixel.R(10, 15, 30, 25)},
-
-		{squareAroundOrigin, resizeByHalfAroundMin, pixel.R(-10, -10, 0, 0)},
-		{squareAround2020, resizeByHalfAroundMin, pixel.R(10, 10, 20, 20)},
-		{rectangleAroundOrigin, resizeByHalfAroundMin, pixel.R(-20, -10, 0, 0)},
-		{rectangleAround2020, resizeByHalfAroundMin, pixel.R(0, 10, 20, 20)},
-
-		{squareAroundOrigin, resizeByHalfAroundMax, pixel.R(0, 0, 10, 10)},
-		{squareAround2020, resizeByHalfAroundMax, pixel.R(20, 20, 30, 30)},
-		{rectangleAroundOrigin, resizeByHalfAroundMax, pixel.R(0, 0, 20, 10)},
-		{rectangleAround2020, resizeByHalfAroundMax, pixel.R(20, 20, 40, 30)},
-
-		{squareAroundOrigin, resizeByHalfAroundMiddleOfLeftSide, pixel.R(-10, -5, 0, 5)},
-		{squareAround2020, resizeByHalfAroundMiddleOfLeftSide, pixel.R(10, 15, 20, 25)},
-		{rectangleAroundOrigin, resizeByHalfAroundMiddleOfLeftSide, pixel.R(-20, -5, 0, 5)},
-		{rectangleAround2020, resizeByHalfAroundMiddleOfLeftSide, pixel.R(0, 15, 20, 25)},
-
-		{squareAroundOrigin, resizeByHalfAroundOrigin, pixel.R(-5, -5, 5, 5)},
-		{squareAround2020, resizeByHalfAroundOrigin, pixel.R(5, 5, 15, 15)},
-		{rectangleAroundOrigin, resizeByHalfAroundOrigin, pixel.R(-10, -5, 10, 5)},
-		{rectangleAround2020, resizeByHalfAroundOrigin, pixel.R(0, 5, 20, 15)},
-	}
-
-	for _, testCase := range testCases {
-		t.Run(fmt.Sprintf("Resize %v %s", testCase.input, testCase.transform.name), func(t *testing.T) {
-			testResult := testCase.transform.f(testCase.input)
-			if testResult != testCase.answer {
-				t.Errorf("Got: %v, wanted: %v\n", testResult, testCase.answer)
-			}
-		})
-	}
-}
-
-func TestRect_Edges(t *testing.T) {
-	type fields struct {
-		Min pixel.Vec
-		Max pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   [4]pixel.Line
-	}{
-		{
-			name:   "Get edges",
-			fields: fields{Min: pixel.V(0, 0), Max: pixel.V(10, 10)},
-			want: [4]pixel.Line{
-				pixel.L(pixel.V(0, 0), pixel.V(0, 10)),
-				pixel.L(pixel.V(0, 10), pixel.V(10, 10)),
-				pixel.L(pixel.V(10, 10), pixel.V(10, 0)),
-				pixel.L(pixel.V(10, 0), pixel.V(0, 0)),
-			},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			r := pixel.Rect{
-				Min: tt.fields.Min,
-				Max: tt.fields.Max,
-			}
-			if got := r.Edges(); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Rect.Edges() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestRect_Vertices(t *testing.T) {
-	type fields struct {
-		Min pixel.Vec
-		Max pixel.Vec
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		want   [4]pixel.Vec
-	}{
-		{
-			name:   "Get corners",
-			fields: fields{Min: pixel.V(0, 0), Max: pixel.V(10, 10)},
-			want: [4]pixel.Vec{
-				pixel.V(0, 0),
-				pixel.V(0, 10),
-				pixel.V(10, 10),
-				pixel.V(10, 0),
-			},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			r := pixel.Rect{
-				Min: tt.fields.Min,
-				Max: tt.fields.Max,
-			}
-			if got := r.Vertices(); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Rect.Vertices() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestRect_IntersectCircle(t *testing.T) {
-	type fields struct {
-		Min pixel.Vec
-		Max pixel.Vec
-	}
-	type args struct {
-		c pixel.Circle
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   pixel.Vec
-	}{
-		{
-			name:   "Rect.IntersectCircle(): no overlap",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(50, 50), 1)},
-			want:   pixel.ZV,
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle contains rect",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(5, 5), 10)},
-			want:   pixel.V(-15, 0),
-		},
-		{
-			name:   "Rect.IntersectCircle(): rect contains circle",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(5, 5), 1)},
-			want:   pixel.V(-6, 0),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps bottom-left corner",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(-0.5, -0.5), 1)},
-			want:   pixel.V(-0.2, -0.2),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps top-left corner",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(-0.5, 10.5), 1)},
-			want:   pixel.V(-0.2, 0.2),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps bottom-right corner",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(10.5, -0.5), 1)},
-			want:   pixel.V(0.2, -0.2),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps top-right corner",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(10.5, 10.5), 1)},
-			want:   pixel.V(0.2, 0.2),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps two corners",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(0, 5), 6)},
-			want:   pixel.V(6, 0),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps left edge",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(0, 5), 1)},
-			want:   pixel.V(1, 0),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps bottom edge",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(5, 0), 1)},
-			want:   pixel.V(0, 1),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps right edge",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(10, 5), 1)},
-			want:   pixel.V(-1, 0),
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle overlaps top edge",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(5, 10), 1)},
-			want:   pixel.V(0, -1),
-		},
-		{
-			name:   "Rect.IntersectCircle(): edge is tangent of left side",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(-1, 5), 1)},
-			want:   pixel.ZV,
-		},
-		{
-			name:   "Rect.IntersectCircle(): edge is tangent of top side",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(5, -1), 1)},
-			want:   pixel.ZV,
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle above rectangle",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(5, 12), 1)},
-			want:   pixel.ZV,
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle below rectangle",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(5, -2), 1)},
-			want:   pixel.ZV,
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle left of rectangle",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(-1, 5), 1)},
-			want:   pixel.ZV,
-		},
-		{
-			name:   "Rect.IntersectCircle(): circle right of rectangle",
-			fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
-			args:   args{c: pixel.C(pixel.V(11, 5), 1)},
-			want:   pixel.ZV,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			r := pixel.Rect{
-				Min: tt.fields.Min,
-				Max: tt.fields.Max,
-			}
-			got := r.IntersectCircle(tt.args.c)
-			if !closeEnough(got.X, tt.want.X, 2) || !closeEnough(got.Y, tt.want.Y, 2) {
-				t.Errorf("Rect.IntersectCircle() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestRect_IntersectionPoints(t *testing.T) {
-	type fields struct {
-		Min pixel.Vec
-		Max pixel.Vec
-	}
-	type args struct {
-		l pixel.Line
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   []pixel.Vec
-	}{
-		{
-			name:   "No intersection points",
-			fields: fields{Min: pixel.V(1, 1), Max: pixel.V(5, 5)},
-			args:   args{l: pixel.L(pixel.V(-5, 0), pixel.V(-2, 2))},
-			want:   []pixel.Vec{},
-		},
-		{
-			name:   "One intersection point",
-			fields: fields{Min: pixel.V(1, 1), Max: pixel.V(5, 5)},
-			args:   args{l: pixel.L(pixel.V(2, 0), pixel.V(2, 3))},
-			want:   []pixel.Vec{pixel.V(2, 1)},
-		},
-		{
-			name:   "Two intersection points",
-			fields: fields{Min: pixel.V(1, 1), Max: pixel.V(5, 5)},
-			args:   args{l: pixel.L(pixel.V(0, 2), pixel.V(6, 2))},
-			want:   []pixel.Vec{pixel.V(1, 2), pixel.V(5, 2)},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			r := pixel.Rect{
-				Min: tt.fields.Min,
-				Max: tt.fields.Max,
-			}
-			if got := r.IntersectionPoints(tt.args.l); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Rect.IntersectPoints() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-var rectIntTests = []struct {
-	name      string
-	r1, r2    pixel.Rect
-	want      pixel.Rect
-	intersect bool
-}{
-	{
-		name: "Nothing touching",
-		r1:   pixel.R(0, 0, 10, 10),
-		r2:   pixel.R(21, 21, 40, 40),
-		want: pixel.ZR,
-	},
-	{
-		name: "Edge touching",
-		r1:   pixel.R(0, 0, 10, 10),
-		r2:   pixel.R(10, 10, 20, 20),
-		want: pixel.ZR,
-	},
-	{
-		name:      "Bit of overlap",
-		r1:        pixel.R(0, 0, 10, 10),
-		r2:        pixel.R(0, 9, 20, 20),
-		want:      pixel.R(0, 9, 10, 10),
-		intersect: true,
-	},
-	{
-		name:      "Fully overlapped",
-		r1:        pixel.R(0, 0, 10, 10),
-		r2:        pixel.R(0, 0, 10, 10),
-		want:      pixel.R(0, 0, 10, 10),
-		intersect: true,
-	},
-}
-
-func TestRect_Intersect(t *testing.T) {
-	for _, tt := range rectIntTests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := tt.r1.Intersect(tt.r2); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("Rect.Intersect() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestRect_Intersects(t *testing.T) {
-	for _, tt := range rectIntTests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := tt.r1.Intersects(tt.r2); got != tt.intersect {
-				t.Errorf("Rect.Intersects() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}

sprite.go

@@ -27,7 +27,7 @@ func NewSprite(pic Picture, frame Rect) *Sprite {
 	tri := MakeTrianglesData(6)
 	s := &Sprite{
 		tri: tri,
-		d:   Drawer{Triangles: tri, Cached: true},
+		d:   Drawer{Triangles: tri},
 	}
 	s.matrix = IM
 	s.mask = Alpha(1)
@@ -44,13 +44,6 @@ func (s *Sprite) Set(pic Picture, frame Rect) {
 	}
 }
 
-// SetCached makes the sprite cache all the
-// incoming pictures if the argument is true, and
-// doesn't make it do that if the argument is false.
-func (s *Sprite) SetCached(cached bool) {
-	s.d.Cached = cached
-}
-
 // Picture returns the current Sprite's Picture.
 func (s *Sprite) Picture() Picture {
 	return s.d.Picture
@@ -112,7 +105,12 @@ func (s *Sprite) calcData() {
 		(*s.tri)[i].Color = s.mask
 		(*s.tri)[i].Picture = center.Add((*s.tri)[i].Position)
 		(*s.tri)[i].Intensity = 1
+	}
+
+	// matrix and mask
+	for i := range *s.tri {
 		(*s.tri)[i].Position = s.matrix.Project((*s.tri)[i].Position)
+		(*s.tri)[i].Color = s.mask
 	}
 
 	s.d.Dirty()

text/atlas.go

@@ -1,6 +1,7 @@
 package text
 
 import (
+	"fmt"
 	"image"
 	"image/draw"
 	"sort"
@@ -11,9 +12,6 @@ import (
 	"golang.org/x/image/math/fixed"
 )
 
-// Atlas7x13 is an Atlas using basicfont.Face7x13 with the ASCII rune set
-var Atlas7x13 *Atlas
-
 // Glyph describes one glyph in an Atlas.
 type Glyph struct {
 	Dot     pixel.Vec
@@ -59,9 +57,8 @@ func NewAtlas(face font.Face, runeSets ...[]rune) *Atlas {
 	))
 
 	for r, fg := range fixedMapping {
-		if dr, mask, maskp, _, ok := face.Glyph(fg.dot, r); ok {
-			draw.Draw(atlasImg, dr, mask, maskp, draw.Src)
-		}
+		dr, mask, maskp, _, _ := face.Glyph(fg.dot, r)
+		draw.Draw(atlasImg, dr, mask, maskp, draw.Src)
 	}
 
 	bounds := pixel.R(
@@ -203,6 +200,7 @@ func makeMapping(face font.Face, runes []rune, padding, width fixed.Int26_6) (ma
 	for _, r := range runes {
 		b, advance, ok := face.GlyphBounds(r)
 		if !ok {
+			fmt.Println(r)
 			continue
 		}
 
@@ -245,3 +243,7 @@ func makeMapping(face font.Face, runes []rune, padding, width fixed.Int26_6) (ma
 func i2f(i fixed.Int26_6) float64 {
 	return float64(i) / (1 << 6)
 }
+
+func f2i(f float64) fixed.Int26_6 {
+	return fixed.Int26_6(f * (1 << 6))
+}

text/atlas_test.go

@@ -1,29 +0,0 @@
-package text_test
-
-import (
-	"testing"
-
-	"github.com/faiface/pixel/text"
-	"golang.org/x/image/font/inconsolata"
-)
-
-func TestAtlas7x13(t *testing.T) {
-	if text.Atlas7x13 == nil {
-		t.Fatalf("Atlas7x13 is nil")
-	}
-
-	for _, tt := range []struct {
-		runes []rune
-		want  bool
-	}{{text.ASCII, true}, {[]rune("ÅÄÖ"), false}} {
-		for _, r := range tt.runes {
-			if got := text.Atlas7x13.Contains(r); got != tt.want {
-				t.Fatalf("Atlas7x13.Contains('%s') = %v, want %v", string(r), got, tt.want)
-			}
-		}
-	}
-}
-
-func TestAtlasInconsolata(t *testing.T) {
-	text.NewAtlas(inconsolata.Regular8x16, text.ASCII)
-}

text/text.go

@@ -7,7 +7,6 @@ import (
 	"unicode/utf8"
 
 	"github.com/faiface/pixel"
-	"golang.org/x/image/font/basicfont"
 )
 
 // ASCII is a set of all ASCII runes. These runes are codepoints from 32 to 127 inclusive.
@@ -18,7 +17,6 @@ func init() {
 	for i := range ASCII {
 		ASCII[i] = rune(32 + i)
 	}
-	Atlas7x13 = NewAtlas(basicfont.Face7x13, ASCII)
 }
 
 // RangeTable takes a *unicode.RangeTable and generates a set of runes contained within that
@@ -62,7 +60,10 @@ func RangeTable(table *unicode.RangeTable) []rune {
 // Text exports two important fields: Orig and Dot. Dot is the position where the next character
 // will be written. Dot is automatically moved when writing to a Text object, but you can also
 // manipulate it manually. Orig specifies the text origin, usually the top-left dot position. Dot is
-// always aligned to Orig when writing newlines. The Clear method resets the Dot to Orig.
+// always aligned to Orig when writing newlines.
+//
+// To reset the Dot to the Orig, just assign it:
+//   txt.Dot = txt.Orig
 type Text struct {
 	// Orig specifies the text origin, usually the top-left dot position. Dot is always aligned
 	// to Orig when writing newlines.
@@ -101,7 +102,6 @@ type Text struct {
 	trans  pixel.TrianglesData
 	transD pixel.Drawer
 	dirty  bool
-	anchor pixel.Anchor
 }
 
 // New creates a new Text capable of drawing runes contained in the provided Atlas. Orig and Dot
@@ -136,7 +136,6 @@ func New(orig pixel.Vec, atlas *Atlas) *Text {
 
 	txt.transD.Picture = txt.atlas.pic
 	txt.transD.Triangles = &txt.trans
-	txt.transD.Cached = true
 
 	txt.Clear()
 
@@ -184,19 +183,12 @@ func (txt *Text) BoundsOf(s string) pixel.Rect {
 	return bounds
 }
 
-// AlignedTo returns the text moved by the given anchor.
-func (txt *Text) AlignedTo(anchor pixel.Anchor) *Text {
-	txt.anchor = anchor
-	return txt
-}
-
-// Clear removes all written text from the Text. The Dot field is reset to Orig.
+// Clear removes all written text from the Text.
 func (txt *Text) Clear() {
 	txt.prevR = -1
 	txt.bounds = pixel.Rect{}
 	txt.tris.SetLen(0)
 	txt.dirty = true
-	txt.Dot = txt.Orig
 }
 
 // Write writes a slice of bytes to the Text. This method never fails, always returns len(p), nil.
@@ -252,10 +244,6 @@ func (txt *Text) DrawColorMask(t pixel.Target, matrix pixel.Matrix, mask color.C
 		txt.mat = matrix
 		txt.dirty = true
 	}
-
-	offset := txt.Orig.Sub(txt.Bounds().Max.Add(txt.Bounds().AnchorPos(txt.anchor.Opposite())))
-	txt.mat = pixel.IM.Moved(offset).Chained(txt.mat)
-
 	if mask == nil {
 		mask = pixel.Alpha(1)
 	}

text/text_test.go

@@ -1,87 +0,0 @@
-package text_test
-
-import (
-	"fmt"
-	"math/rand"
-	"testing"
-	"unicode"
-
-	"golang.org/x/image/font/basicfont"
-	"golang.org/x/image/font/gofont/goregular"
-
-	"github.com/faiface/pixel"
-	"github.com/faiface/pixel/text"
-	"github.com/golang/freetype/truetype"
-)
-
-func TestClear(t *testing.T) {
-	txt := text.New(pixel.ZV, text.Atlas7x13)
-
-	if got, want := txt.Dot, pixel.ZV; !eqVectors(got, want) {
-		t.Fatalf("txt.Dot = %v, want %v", got, want)
-	}
-
-	fmt.Fprint(txt, "Test\nClear")
-
-	if got, want := txt.Dot, pixel.V(35, -13); !eqVectors(got, want) {
-		t.Fatalf("txt.Dot = %v, want %v", got, want)
-	}
-
-	txt.Clear()
-
-	if got, want := txt.Dot, pixel.ZV; !eqVectors(got, want) {
-		t.Fatalf("txt.Dot = %v, want %v", got, want)
-	}
-}
-
-func BenchmarkNewAtlas(b *testing.B) {
-	runeSets := []struct {
-		name string
-		set  []rune
-	}{
-		{"ASCII", text.ASCII},
-		{"Latin", text.RangeTable(unicode.Latin)},
-	}
-
-	ttf, _ := truetype.Parse(goregular.TTF)
-	face := truetype.NewFace(ttf, &truetype.Options{
-		Size:              16,
-		GlyphCacheEntries: 1,
-	})
-
-	for _, runeSet := range runeSets {
-		b.Run(runeSet.name, func(b *testing.B) {
-			for i := 0; i < b.N; i++ {
-				_ = text.NewAtlas(face, runeSet.set)
-			}
-		})
-	}
-}
-
-func BenchmarkTextWrite(b *testing.B) {
-	runeSet := text.ASCII
-	atlas := text.NewAtlas(basicfont.Face7x13, runeSet)
-
-	lengths := []int{1, 10, 100, 1000}
-	chunks := make([][]byte, len(lengths))
-	for i := range chunks {
-		chunk := make([]rune, lengths[i])
-		for j := range chunk {
-			chunk[j] = runeSet[rand.Intn(len(runeSet))]
-		}
-		chunks[i] = []byte(string(chunk))
-	}
-
-	for _, chunk := range chunks {
-		b.Run(fmt.Sprintf("%d", len(chunk)), func(b *testing.B) {
-			txt := text.New(pixel.ZV, atlas)
-			for i := 0; i < b.N; i++ {
-				_, _ = txt.Write(chunk)
-			}
-		})
-	}
-}
-
-func eqVectors(a, b pixel.Vec) bool {
-	return (a.X == b.X && a.Y == b.Y)
-}

vector.go

@@ -1,462 +0,0 @@
-package pixel
-
-import (
-	"fmt"
-	"math"
-)
-
-// Vec is a 2D vector type with X and Y coordinates.
-//
-// Create vectors with the V constructor:
-//
-//   u := pixel.V(1, 2)
-//   v := pixel.V(8, -3)
-//
-// Use various methods to manipulate them:
-//
-//   w := u.Add(v)
-//   fmt.Println(w)        // Vec(9, -1)
-//   fmt.Println(u.Sub(v)) // Vec(-7, 5)
-//   u = pixel.V(2, 3)
-//   v = pixel.V(8, 1)
-//   if u.X < 0 {
-//	     fmt.Println("this won't happen")
-//   }
-//   x := u.Unit().Dot(v.Unit())
-type Vec struct {
-	X, Y float64
-}
-
-// ZV is a zero vector.
-var ZV = Vec{0, 0}
-
-// V returns a new 2D vector with the given coordinates.
-func V(x, y float64) Vec {
-	return Vec{x, y}
-}
-
-// nearlyEqual compares two float64s and returns whether they are equal, accounting for rounding errors.At worst, the
-// result is correct to 7 significant digits.
-func nearlyEqual(a, b float64) bool {
-	epsilon := 0.000001
-
-	if a == b {
-		return true
-	}
-
-	diff := math.Abs(a - b)
-
-	if a == 0.0 || b == 0.0 || diff < math.SmallestNonzeroFloat64 {
-		return diff < (epsilon * math.SmallestNonzeroFloat64)
-	}
-
-	absA := math.Abs(a)
-	absB := math.Abs(b)
-
-	return diff/math.Min(absA+absB, math.MaxFloat64) < epsilon
-}
-
-// Eq will compare two vectors and return whether they are equal accounting for rounding errors.  At worst, the result
-// is correct to 7 significant digits.
-func (u Vec) Eq(v Vec) bool {
-	return nearlyEqual(u.X, v.X) && nearlyEqual(u.Y, v.Y)
-}
-
-// Unit returns a vector of length 1 facing the given angle.
-func Unit(angle float64) Vec {
-	return Vec{1, 0}.Rotated(angle)
-}
-
-// String returns the string representation of the vector u.
-//
-//   u := pixel.V(4.5, -1.3)
-//   u.String()     // returns "Vec(4.5, -1.3)"
-//   fmt.Println(u) // Vec(4.5, -1.3)
-func (u Vec) String() string {
-	return fmt.Sprintf("Vec(%v, %v)", u.X, u.Y)
-}
-
-// XY returns the components of the vector in two return values.
-func (u Vec) XY() (x, y float64) {
-	return u.X, u.Y
-}
-
-// Add returns the sum of vectors u and v.
-func (u Vec) Add(v Vec) Vec {
-	return Vec{
-		u.X + v.X,
-		u.Y + v.Y,
-	}
-}
-
-// Sub returns the difference betweeen vectors u and v.
-func (u Vec) Sub(v Vec) Vec {
-	return Vec{
-		u.X - v.X,
-		u.Y - v.Y,
-	}
-}
-
-// Floor converts x and y to their integer equivalents.
-func (u Vec) Floor() Vec {
-	return Vec{
-		math.Floor(u.X),
-		math.Floor(u.Y),
-	}
-}
-
-// To returns the vector from u to v. Equivalent to v.Sub(u).
-func (u Vec) To(v Vec) Vec {
-	return Vec{
-		v.X - u.X,
-		v.Y - u.Y,
-	}
-}
-
-// Scaled returns the vector u multiplied by c.
-func (u Vec) Scaled(c float64) Vec {
-	return Vec{u.X * c, u.Y * c}
-}
-
-// ScaledXY returns the vector u multiplied by the vector v component-wise.
-func (u Vec) ScaledXY(v Vec) Vec {
-	return Vec{u.X * v.X, u.Y * v.Y}
-}
-
-// Len returns the length of the vector u.
-func (u Vec) Len() float64 {
-	return math.Hypot(u.X, u.Y)
-}
-
-// SqLen returns the squared length of the vector u (faster to compute than Len).
-func (u Vec) SqLen() float64 {
-	return u.X*u.X + u.Y*u.Y
-}
-
-// Angle returns the angle between the vector u and the x-axis. The result is in range [-Pi, Pi].
-func (u Vec) Angle() float64 {
-	return math.Atan2(u.Y, u.X)
-}
-
-// Unit returns a vector of length 1 facing the direction of u (has the same angle).
-func (u Vec) Unit() Vec {
-	if u.X == 0 && u.Y == 0 {
-		return Vec{1, 0}
-	}
-	return u.Scaled(1 / u.Len())
-}
-
-// Rotated returns the vector u rotated by the given angle in radians.
-func (u Vec) Rotated(angle float64) Vec {
-	sin, cos := math.Sincos(angle)
-	return Vec{
-		u.X*cos - u.Y*sin,
-		u.X*sin + u.Y*cos,
-	}
-}
-
-// Normal returns a vector normal to u. Equivalent to u.Rotated(math.Pi / 2), but faster.
-func (u Vec) Normal() Vec {
-	return Vec{-u.Y, u.X}
-}
-
-// Dot returns the dot product of vectors u and v.
-func (u Vec) Dot(v Vec) float64 {
-	return u.X*v.X + u.Y*v.Y
-}
-
-// Cross return the cross product of vectors u and v.
-func (u Vec) Cross(v Vec) float64 {
-	return u.X*v.Y - v.X*u.Y
-}
-
-// Project returns a projection (or component) of vector u in the direction of vector v.
-//
-// Behaviour is undefined if v is a zero vector.
-func (u Vec) Project(v Vec) Vec {
-	len := u.Dot(v) / v.Len()
-	return v.Unit().Scaled(len)
-}
-
-// Map applies the function f to both x and y components of the vector u and returns the modified
-// vector.
-//
-//   u := pixel.V(10.5, -1.5)
-//   v := u.Map(math.Floor)   // v is Vec(10, -2), both components of u floored
-func (u Vec) Map(f func(float64) float64) Vec {
-	return Vec{
-		f(u.X),
-		f(u.Y),
-	}
-}
-
-// Lerp returns a linear interpolation between vectors a and b.
-//
-// This function basically returns a point along the line between a and b and t chooses which one.
-// If t is 0, then a will be returned, if t is 1, b will be returned. Anything between 0 and 1 will
-// return the appropriate point between a and b and so on.
-func Lerp(a, b Vec, t float64) Vec {
-	return a.Scaled(1 - t).Add(b.Scaled(t))
-}
-
-// Line is a 2D line segment, between points A and B.
-type Line struct {
-	A, B Vec
-}
-
-// L creates and returns a new Line.
-func L(from, to Vec) Line {
-	return Line{
-		A: from,
-		B: to,
-	}
-}
-
-// Bounds returns the lines bounding box.  This is in the form of a normalized Rect.
-func (l Line) Bounds() Rect {
-	return R(l.A.X, l.A.Y, l.B.X, l.B.Y).Norm()
-}
-
-// Center will return the point at center of the line; that is, the point equidistant from either end.
-func (l Line) Center() Vec {
-	return l.A.Add(l.A.To(l.B).Scaled(0.5))
-}
-
-// Closest will return the point on the line which is closest to the Vec provided.
-func (l Line) Closest(v Vec) Vec {
-	// between is a helper function which determines whether x is greater than min(a, b) and less than max(a, b)
-	between := func(a, b, x float64) bool {
-		min := math.Min(a, b)
-		max := math.Max(a, b)
-		return min < x && x < max
-	}
-
-	// Closest point will be on a line which perpendicular to this line.
-	// If and only if the infinite perpendicular line intersects the segment.
-	m, b := l.Formula()
-
-	// Account for horizontal lines
-	if m == 0 {
-		x := v.X
-		y := l.A.Y
-
-		// check if the X coordinate of v is on the line
-		if between(l.A.X, l.B.X, v.X) {
-			return V(x, y)
-		}
-
-		// Otherwise get the closest endpoint
-		if l.A.To(v).Len() < l.B.To(v).Len() {
-			return l.A
-		}
-		return l.B
-	}
-
-	// Account for vertical lines
-	if math.IsInf(math.Abs(m), 1) {
-		x := l.A.X
-		y := v.Y
-
-		// check if the Y coordinate of v is on the line
-		if between(l.A.Y, l.B.Y, v.Y) {
-			return V(x, y)
-		}
-
-		// Otherwise get the closest endpoint
-		if l.A.To(v).Len() < l.B.To(v).Len() {
-			return l.A
-		}
-		return l.B
-	}
-
-	perpendicularM := -1 / m
-	perpendicularB := v.Y - (perpendicularM * v.X)
-
-	// Coordinates of intersect (of infinite lines)
-	x := (perpendicularB - b) / (m - perpendicularM)
-	y := m*x + b
-
-	// Check if the point lies between the x and y bounds of the segment
-	if !between(l.A.X, l.B.X, x) && !between(l.A.Y, l.B.Y, y) {
-		// Not within bounding box
-		toStart := v.To(l.A)
-		toEnd := v.To(l.B)
-
-		if toStart.Len() < toEnd.Len() {
-			return l.A
-		}
-		return l.B
-	}
-
-	return V(x, y)
-}
-
-// Contains returns whether the provided Vec lies on the line.
-func (l Line) Contains(v Vec) bool {
-	return l.Closest(v).Eq(v)
-}
-
-// Formula will return the values that represent the line in the formula: y = mx + b
-// This function will return math.Inf+, math.Inf- for a vertical line.
-func (l Line) Formula() (m, b float64) {
-	// Account for horizontal lines
-	if l.B.Y == l.A.Y {
-		return 0, l.A.Y
-	}
-
-	m = (l.B.Y - l.A.Y) / (l.B.X - l.A.X)
-	b = l.A.Y - (m * l.A.X)
-
-	return m, b
-}
-
-// Intersect will return the point of intersection for the two line segments.  If the line segments do not intersect,
-// this function will return the zero-vector and false.
-func (l Line) Intersect(k Line) (Vec, bool) {
-	// Check if the lines are parallel
-	lDir := l.A.To(l.B)
-	kDir := k.A.To(k.B)
-	if lDir.X == kDir.X && lDir.Y == kDir.Y {
-		return ZV, false
-	}
-
-	// The lines intersect - but potentially not within the line segments.
-	// Get the intersection point for the lines if they were infinitely long, check if the point exists on both of the
-	// segments
-	lm, lb := l.Formula()
-	km, kb := k.Formula()
-
-	// Account for vertical lines
-	if math.IsInf(math.Abs(lm), 1) && math.IsInf(math.Abs(km), 1) {
-		// Both vertical, therefore parallel
-		return ZV, false
-	}
-
-	var x, y float64
-
-	if math.IsInf(math.Abs(lm), 1) || math.IsInf(math.Abs(km), 1) {
-		// One line is vertical
-		intersectM := lm
-		intersectB := lb
-		verticalLine := k
-
-		if math.IsInf(math.Abs(lm), 1) {
-			intersectM = km
-			intersectB = kb
-			verticalLine = l
-		}
-
-		y = intersectM*verticalLine.A.X + intersectB
-		x = verticalLine.A.X
-	} else {
-		// Coordinates of intersect
-		x = (kb - lb) / (lm - km)
-		y = lm*x + lb
-	}
-
-	if l.Contains(V(x, y)) && k.Contains(V(x, y)) {
-		// The intersect point is on both line segments, they intersect.
-		return V(x, y), true
-	}
-
-	return ZV, false
-}
-
-// IntersectCircle will return the shortest Vec such that moving the Line by that Vec will cause the Line and Circle
-// to no longer intesect.  If they do not intersect at all, this function will return a zero-vector.
-func (l Line) IntersectCircle(c Circle) Vec {
-	// Get the point on the line closest to the center of the circle.
-	closest := l.Closest(c.Center)
-	cirToClosest := c.Center.To(closest)
-
-	if cirToClosest.Len() >= c.Radius {
-		return ZV
-	}
-
-	return cirToClosest.Scaled(cirToClosest.Len() - c.Radius)
-}
-
-// IntersectRect will return the shortest Vec such that moving the Line by that Vec will cause  the Line and Rect to
-// no longer intesect.  If they do not intersect at all, this function will return a zero-vector.
-func (l Line) IntersectRect(r Rect) Vec {
-	// Check if either end of the line segment are within the rectangle
-	if r.Contains(l.A) || r.Contains(l.B) {
-		// Use the Rect.Intersect to get minimal return value
-		rIntersect := l.Bounds().Intersect(r)
-		if rIntersect.H() > rIntersect.W() {
-			// Go vertical
-			return V(0, rIntersect.H())
-		}
-		return V(rIntersect.W(), 0)
-	}
-
-	// Check if any of the rectangles' edges intersect with this line.
-	for _, edge := range r.Edges() {
-		if _, ok := l.Intersect(edge); ok {
-			// Get the closest points on the line to each corner, where:
-			//  - the point is contained by the rectangle
-			//  - the point is not the corner itself
-			corners := r.Vertices()
-			var closest *Vec
-			closestCorner := corners[0]
-			for _, c := range corners {
-				cc := l.Closest(c)
-				if closest == nil || (closest.Len() > cc.Len() && r.Contains(cc)) {
-					closest = &cc
-					closestCorner = c
-				}
-			}
-
-			return closest.To(closestCorner)
-		}
-	}
-
-	// No intersect
-	return ZV
-}
-
-// Len returns the length of the line segment.
-func (l Line) Len() float64 {
-	return l.A.To(l.B).Len()
-}
-
-// Moved will return a line moved by the delta Vec provided.
-func (l Line) Moved(delta Vec) Line {
-	return Line{
-		A: l.A.Add(delta),
-		B: l.B.Add(delta),
-	}
-}
-
-// Rotated will rotate the line around the provided Vec.
-func (l Line) Rotated(around Vec, angle float64) Line {
-	// Move the line so we can use `Vec.Rotated`
-	lineShifted := l.Moved(around.Scaled(-1))
-
-	lineRotated := Line{
-		A: lineShifted.A.Rotated(angle),
-		B: lineShifted.B.Rotated(angle),
-	}
-
-	return lineRotated.Moved(around)
-}
-
-// Scaled will return the line scaled around the center point.
-func (l Line) Scaled(scale float64) Line {
-	return l.ScaledXY(l.Center(), scale)
-}
-
-// ScaledXY will return the line scaled around the Vec provided.
-func (l Line) ScaledXY(around Vec, scale float64) Line {
-	toA := around.To(l.A).Scaled(scale)
-	toB := around.To(l.B).Scaled(scale)
-
-	return Line{
-		A: around.Add(toA),
-		B: around.Add(toB),
-	}
-}
-
-func (l Line) String() string {
-	return fmt.Sprintf("Line(%v, %v)", l.A, l.B)
-}

vector_test.go

@@ -1,27 +0,0 @@
-package pixel_test
-
-import (
-	"fmt"
-	"testing"
-
-	"github.com/faiface/pixel"
-)
-
-type floorTest struct {
-	input    pixel.Vec
-	expected pixel.Vec
-}
-
-func TestFloor(t *testing.T) {
-	tests := []floorTest{
-		{input: pixel.V(4.50, 6.70), expected: pixel.V(4, 6)},
-		{input: pixel.V(9.0, 6.70), expected: pixel.V(9, 6)},
-	}
-
-	for _, tc := range tests {
-		result := tc.input.Floor()
-		if result != tc.expected {
-			t.Error(fmt.Sprintf("Expected %v but got %v", tc.expected, result))
-		}
-	}
-}