58 lines
1.2 KiB
Go
58 lines
1.2 KiB
Go
package main
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import (
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"fmt"
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"exp/draw"
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"exp/draw/x11"
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"image"
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"math"
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"draw2d.googlecode.com/hg/draw2d"
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)
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func main() {
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window, err := x11.NewWindow()
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if err != nil {
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fmt.Printf("Cannot open an x11 window\n")
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return
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}
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screen := window.Screen()
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gc := draw2d.NewGraphicContext(screen)
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gc.SetStrokeColor(image.Black)
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gc.SetFillColor(image.White)
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gc.Clear()
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for i := 0.0; i < 360; i = i + 10 { // Go from 0 to 360 degrees in 10 degree steps
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gc.BeginPath() // Start a new path
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gc.Save() // Keep rotations temporary
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gc.MoveTo(144, 144)
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gc.Rotate(i * (math.Pi / 180.0)) // Rotate by degrees on stack from 'for'
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gc.RLineTo(72, 0)
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gc.Stroke()
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gc.Restore() // Get back the unrotated state
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}
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window.FlushImage()
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gc.SetLineWidth(3)
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nbclick := 0
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for {
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switch evt := (<-window.EventChan()).(type) {
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case draw.KeyEvent:
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if evt.Key == 'q' {
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window.Close()
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}
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case draw.MouseEvent:
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if evt.Buttons&1 != 0 {
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if nbclick%2 == 0 {
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gc.MoveTo(float64(evt.Loc.X), float64(evt.Loc.Y))
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} else {
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gc.LineTo(float64(evt.Loc.X), float64(evt.Loc.Y))
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gc.Stroke()
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window.FlushImage()
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}
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nbclick = nbclick + 1
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}
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}
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}
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}
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