func update(screen *ebiten.Image) error {
if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
count++
}
mx, my := ebiten.CursorPosition()
if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
op := &ebiten.DrawImageOptions{}
op.GeoM.Translate(float64(mx), float64(my))
op.ColorM.Scale(1.0, 0.25, 0.25, 1.0)
theta := 2.0 * math.Pi * float64(count%60) / 60.0
op.ColorM.Concat(ebiten.RotateHue(theta))
if err := canvasImage.DrawImage(brushImage, op); err != nil {
return err
}
}
if err := screen.DrawImage(canvasImage, nil); err != nil {
return err
}
if err := ebitenutil.DebugPrint(screen, fmt.Sprintf("(%d, %d)", mx, my)); err != nil {
return err
}
return nil
}
func update(screen *ebiten.Image) error {
count++
w, h := gophersImage.Size()
op := &ebiten.DrawImageOptions{}
op.GeoM.Translate(float64(screenWidth-w)/2, float64(screenHeight-h)/2)
op.ColorM.Concat(ebiten.RotateHue(float64(count%360) * 2 * math.Pi / 360))
if err := screen.DrawImage(gophersImage, op); err != nil {
return err
}
return nil
}