90 lines
1.9 KiB
Go
90 lines
1.9 KiB
Go
package main
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import (
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"image/color"
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"github.com/faiface/pixel"
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"github.com/faiface/pixel/imdraw"
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"github.com/faiface/pixel/pixelgl"
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)
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// These hold the state of whether we're placing the first or second point of the line.
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const (
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clickLineA = iota
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clickLineB
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)
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var (
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winBounds = pixel.R(0, 0, 1024, 768)
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r = pixel.R(10, 10, 70, 50)
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l = pixel.L(pixel.V(20, 20), pixel.V(100, 30))
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clickLine = clickLineA
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)
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func run() {
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cfg := pixelgl.WindowConfig{
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Title: "Line collision",
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Bounds: winBounds,
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VSync: true,
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}
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win, err := pixelgl.NewWindow(cfg)
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if err != nil {
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panic(err)
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}
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imd := imdraw.New(nil)
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for !win.Closed() {
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win.Clear(color.RGBA{R: 23, G: 39, B: 58, A: 125})
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imd.Clear()
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// When mouse left-click, move the rectangle so its' center is at the mouse position
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if win.JustPressed(pixelgl.MouseButtonLeft) {
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rectToMouse := r.Center().To(win.MousePosition())
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r = r.Moved(rectToMouse)
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}
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// When mouse right-click, set either the beginning or end of the line.
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if win.JustPressed(pixelgl.MouseButtonRight) {
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if clickLine == clickLineA {
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// Set the beginning of the line to the mouse position.
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// To make it clearer to the user, set the end position 1 pixel (in each direction) away from the first
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// point.
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l = pixel.L(win.MousePosition(), win.MousePosition().Add(pixel.V(1, 1)))
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clickLine = clickLineB
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} else {
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// Set the end point of the line.
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l = pixel.L(l.A, win.MousePosition())
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clickLine = clickLineA
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}
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}
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// Draw the rectangle.
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imd.Color = color.Black
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imd.Push(r.Min, r.Max)
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imd.Rectangle(3)
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// Draw the line.
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imd.Color = color.RGBA{R: 10, G: 10, B: 250, A: 255}
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imd.Push(l.A, l.B)
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imd.Line(3)
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imd.Color = color.RGBA{R: 250, G: 10, B: 10, A: 255}
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// Draw any intersection points.
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for _, i := range r.IntersectionPoints(l) {
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imd.Push(i)
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imd.Circle(4, 0)
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}
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imd.Draw(win)
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win.Update()
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}
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}
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func main() {
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pixelgl.Run(run)
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}
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