interesting
/
go-opengl-pixel
mirror of https://github.com/faiface/pixel.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

add context

This commit is contained in:
faiface 2016-11-28 23:26:56 +01:00
parent 6253156e24
commit 9d4111282e
6 changed files with 76 additions and 95 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
graphics.go
View File

@ -1,58 +0,0 @@
package pixel
import "github.com/faiface/pixel/pixelgl"
// Warning: technical stuff below.
// VertexFormat is an internal format of the OpenGL vertex data.
//
// You can actually change this and all of the Pixel's functions will use the new format.
// Only change when you're implementing an OpenGL effect or something similar.
var VertexFormat = DefaultVertexFormat()
// DefaultVertexFormat returns the default vertex format used by Pixel.
func DefaultVertexFormat() pixelgl.VertexFormat {
return pixelgl.VertexFormat{
{Purpose: pixelgl.Position, Size: 2},
{Purpose: pixelgl.Color, Size: 4},
{Purpose: pixelgl.TexCoord, Size: 2},
}
}
// ConvertVertexData converts data in the oldFormat to the newFormat. Vertex attributes in the new format
// will be copied from the corresponding vertex attributes in the old format. If a vertex attribute in the new format
// has no corresponding attribute in the old format, it will be filled with zeros.
func ConvertVertexData(oldFormat, newFormat pixelgl.VertexFormat, data []float64) []float64 {
// calculate the mapping between old and new format
// if i is a start of a vertex attribute in the new format, then mapping[i] returns
// the index where the same attribute starts in the old format
mapping := make(map[int]int)
i := 0
for _, newAttr := range newFormat {
j := 0
for _, oldAttr := range oldFormat {
if newAttr == oldAttr {
mapping[i] = j
break
}
j += oldAttr.Size
}
i += newAttr.Size
}
oldData, newData := data, []float64{}
for i := 0; i < len(oldData); i += oldFormat.Size() {
j := 0
for _, attr := range newFormat {
if oldIndex, ok := mapping[j]; ok { // the attribute was found in the old format
newData = append(newData, oldData[i+oldIndex:i+oldIndex+attr.Size]...)
} else { // the attribute wasn't found in the old format, so fill with zeros
newData = append(newData, make([]float64, attr.Size)...)
}
j += attr.Size
}
}
return newData
}

47
pixelgl/interface.go
View File

@ -12,10 +12,10 @@ package pixelgl
// The recommended way to implement a Doer is to wrap another Doer (vertex array wraps texture and so on), let's call
// it parent. Then the Do method will look like this:
//
// func (o *MyObject) Do(sub func()) {
// o.parent.Do(func() {
// func (o *MyObject) Do(sub func(Context)) {
// o.parent.Do(func(ctx Context) {
// // enter the object's state
// sub()
// sub(ctx)
// // leave the object's state
// })
// }
@ -23,6 +23,45 @@ package pixelgl
// It might seem difficult to grasp this kind of recursion at first, but it's really simple. What it's basically saying
// is: "Hey parent, enter your state, then let me enter mine, then I'll do whatever I'm supposed to do in the middle.
// After that I'll leave my state and please leave your state too parent."
//
// Also notice, that the functions are passing a Context around. This context contains the most important state variables.
// Usually, you just pass it as you received it. If you want to pass a changed context to your child (e.g. your a shader),
// use ctx.With* methods.
type Doer interface {
Do(sub func())
Do(sub func(Context))
}
// Context takes state from one object to another. OpenGL is a state machine, so we have to approach it like that.
// However, global variables are evil, so we have Context, that transfers important OpenGL state from one object to another.
//
// This type does *not* represent an OpenGL context in the OpenGL terminology.
type Context struct {
vertexFormat VertexFormat
shader *Shader
}
// VertexFormat returns the current vertex format.
func (c Context) VertexFormat() VertexFormat {
return c.vertexFormat
}
// Shader returns the current shader.
func (c Context) Shader() *Shader {
return c.shader
}
// WithVertexFormat returns a copy of this context with the specified vertex format.
func (c Context) WithVertexFormat(vf VertexFormat) Context {
return Context{
vertexFormat: vf,
shader: c.shader,
}
}
// WithShader returns a copy of this context with the specified shader.
func (c Context) WithShader(s *Shader) Context {
return Context{
vertexFormat: c.vertexFormat,
shader: s,
}
}

10
pixelgl/shader.go
View File

@ -22,7 +22,7 @@ func NewShader(parent Doer, vertexShader, fragmentShader string) (*Shader, error
}
var err, glerr error
parent.Do(func() {
parent.Do(func(ctx Context) {
err, glerr = DoErrGLErr(func() error {
var vshader, fshader uint32
@ -105,7 +105,7 @@ func NewShader(parent Doer, vertexShader, fragmentShader string) (*Shader, error
// Delete deletes a shader program. Don't use a shader after deletion.
func (s *Shader) Delete() {
s.parent.Do(func() {
s.parent.Do(func(ctx Context) {
DoNoBlock(func() {
gl.DeleteProgram(s.program)
})
@ -113,12 +113,12 @@ func (s *Shader) Delete() {
}
// Do stars using a shader, executes sub, and stops using it.
func (s *Shader) Do(sub func()) {
s.parent.Do(func() {
func (s *Shader) Do(sub func(Context)) {
s.parent.Do(func(ctx Context) {
DoNoBlock(func() {
gl.UseProgram(s.program)
})
sub()
sub(ctx.WithShader(s))
DoNoBlock(func() {
gl.UseProgram(0)
})

10
pixelgl/texture.go
View File

@ -17,7 +17,7 @@ func NewTexture(parent Doer, width, height int, pixels []uint8) (*Texture, error
texture := &Texture{parent: parent}
var err error
parent.Do(func() {
parent.Do(func(ctx Context) {
err = DoGLErr(func() {
gl.GenTextures(1, &texture.tex)
gl.BindTexture(gl.TEXTURE_2D, texture.tex)
@ -48,7 +48,7 @@ func NewTexture(parent Doer, width, height int, pixels []uint8) (*Texture, error
// Delete deletes a texture. Don't use a texture after deletion.
func (t *Texture) Delete() {
t.parent.Do(func() {
t.parent.Do(func(ctx Context) {
DoNoBlock(func() {
gl.DeleteTextures(1, &t.tex)
})
@ -56,12 +56,12 @@ func (t *Texture) Delete() {
}
// Do bind a texture, executes sub, and unbinds the texture.
func (t *Texture) Do(sub func()) {
t.parent.Do(func() {
func (t *Texture) Do(sub func(Context)) {
t.parent.Do(func(ctx Context) {
DoNoBlock(func() {
gl.BindTexture(gl.TEXTURE_2D, t.tex)
})
sub()
sub(ctx)
DoNoBlock(func() {
gl.BindTexture(gl.TEXTURE_2D, 0)
})

12
pixelgl/vertex.go
View File

@ -125,7 +125,7 @@ func NewVertexArray(parent Doer, format VertexFormat, mode VertexDrawMode, usage
}
var err error
parent.Do(func() {
parent.Do(func(ctx Context) {
err = DoGLErr(func() {
gl.GenVertexArrays(1, &va.vao)
gl.BindVertexArray(va.vao)
@ -161,7 +161,7 @@ func NewVertexArray(parent Doer, format VertexFormat, mode VertexDrawMode, usage
// Delete deletes a vertex array and it's associated vertex buffer. Don't use a vertex array after deletion.
func (va *VertexArray) Delete() {
va.parent.Do(func() {
va.parent.Do(func(ctx Context) {
DoNoBlock(func() {
gl.DeleteVertexArrays(1, &va.vao)
gl.DeleteBuffers(1, &va.vbo)
@ -193,7 +193,7 @@ func (va *VertexArray) DrawMode() VertexDrawMode {
// Draw draws a vertex array.
func (va *VertexArray) Draw() {
va.Do(func() {})
va.Do(func(Context) {})
}
// Data returns a copy of data inside a vertex array (actually it's vertex buffer).
@ -233,13 +233,13 @@ func (va *VertexArray) SetVertexAttribute(vertex int, attr VertexAttribute, data
}
// Do binds a vertex arrray and it's associated vertex buffer, executes sub, and unbinds the vertex array and it's vertex buffer.
func (va *VertexArray) Do(sub func()) {
va.parent.Do(func() {
func (va *VertexArray) Do(sub func(Context)) {
va.parent.Do(func(ctx Context) {
DoNoBlock(func() {
gl.BindVertexArray(va.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, va.vbo)
})
sub()
sub(ctx)
DoNoBlock(func() {
gl.DrawArrays(uint32(va.mode), 0, int32(va.count))
gl.BindBuffer(gl.ARRAY_BUFFER, 0)

34
window.go
View File

@ -108,7 +108,7 @@ func NewWindow(config WindowConfig) (*Window, error) {
// Delete destroys a window. The window can't be used any further.
func (w *Window) Delete() {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.Destroy()
})
@ -117,14 +117,14 @@ func (w *Window) Delete() {
// Clear clears the window with a color.
func (w *Window) Clear(c color.Color) {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Clear(colorToRGBA(c))
})
}
// Update swaps buffers and polls events.
func (w *Window) Update() {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
if w.config.VSync {
glfw.SwapInterval(1)
@ -137,7 +137,7 @@ func (w *Window) Update() {
// SetTitle changes the title of a window.
func (w *Window) SetTitle(title string) {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.SetTitle(title)
})
@ -147,7 +147,7 @@ func (w *Window) SetTitle(title string) {
// SetSize resizes a window to the specified size in pixels.
// In case of a fullscreen window, it changes the resolution of that window.
func (w *Window) SetSize(width, height float64) {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.SetSize(int(width), int(height))
})
@ -156,7 +156,7 @@ func (w *Window) SetSize(width, height float64) {
// Size returns the size of the client area of a window (the part you can draw on).
func (w *Window) Size() (width, height float64) {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
wi, hi := w.window.GetSize()
width = float64(wi)
@ -168,7 +168,7 @@ func (w *Window) Size() (width, height float64) {
// Show makes a window visible if it was hidden.
func (w *Window) Show() {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.Show()
})
@ -177,7 +177,7 @@ func (w *Window) Show() {
// Hide hides a window if it was visible.
func (w *Window) Hide() {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.Hide()
})
@ -191,7 +191,7 @@ func (w *Window) Hide() {
func (w *Window) SetFullscreen(monitor *Monitor) {
if w.Monitor() != monitor {
if monitor == nil {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.SetMonitor(
nil,
@ -204,7 +204,7 @@ func (w *Window) SetFullscreen(monitor *Monitor) {
})
})
} else {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.restore.xpos, w.restore.ypos = w.window.GetPos()
w.restore.width, w.restore.height = w.window.GetSize()
@ -233,7 +233,7 @@ func (w *Window) IsFullscreen() bool {
// Monitor returns a monitor a fullscreen window is on. If the window is not fullscreen, this function returns nil.
func (w *Window) Monitor() *Monitor {
var monitor *glfw.Monitor
w.Do(func() {
w.Do(func(pixelgl.Context) {
monitor = pixelgl.DoVal(func() interface{} {
return w.window.GetMonitor()
}).(*glfw.Monitor)
@ -248,7 +248,7 @@ func (w *Window) Monitor() *Monitor {
// Focus brings a window to the front and sets input focus.
func (w *Window) Focus() {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.Focus()
})
@ -258,7 +258,7 @@ func (w *Window) Focus() {
// Focused returns true if a window has input focus.
func (w *Window) Focused() bool {
var focused bool
w.Do(func() {
w.Do(func(pixelgl.Context) {
focused = pixelgl.DoVal(func() interface{} {
return w.window.GetAttrib(glfw.Focused) == glfw.True
}).(bool)
@ -268,7 +268,7 @@ func (w *Window) Focused() bool {
// Maximize puts a windowed window to a maximized state.
func (w *Window) Maximize() {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.Maximize()
})
@ -277,7 +277,7 @@ func (w *Window) Maximize() {
// Restore restores a windowed window from a maximized state.
func (w *Window) Restore() {
w.Do(func() {
w.Do(func(pixelgl.Context) {
pixelgl.Do(func() {
w.window.Restore()
})
@ -290,7 +290,7 @@ var currentWindow struct {
}
// Do makes the context of this window current, if it's not already, and executes sub.
func (w *Window) Do(sub func()) {
func (w *Window) Do(sub func(pixelgl.Context)) {
currentWindow.Lock()
defer currentWindow.Unlock()
@ -302,5 +302,5 @@ func (w *Window) Do(sub func()) {
currentWindow.handler = w
}
sub()
sub(pixelgl.Context{})
}