Dmitry Sergeev
75 lines
1.7 KiB
Go
75 lines
1.7 KiB
Go
package generator
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import "math"
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const movingSquareSize = 150
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type baseColorFunc func(x, y, width, height int) YCbCr10
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type squareBounds struct {
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minX float64
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maxX float64
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minY float64
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maxY float64
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}
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func movingSquareBounds(width, height, frameIndex int) squareBounds {
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const half = float64(movingSquareSize) / 2
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centerX := float64(width) / 2
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centerY := float64(height) / 2
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time := float64(frameIndex) / 25.0
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offset := math.Sin(time*0.5) * (centerX - half)
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return squareBounds{
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minX: centerX - half + offset,
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maxX: centerX + half + offset,
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minY: centerY - half,
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maxY: centerY + half,
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}
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}
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func (b squareBounds) contains(x, y int) bool {
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return float64(x) >= b.minX && float64(x) < b.maxX &&
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float64(y) >= b.minY && float64(y) < b.maxY
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}
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func patchMovingSquare(
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dst []byte,
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width, height, frameIndex int,
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baseColor baseColorFunc,
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) error {
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bounds := movingSquareBounds(width, height, frameIndex)
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firstPixelX := max(0, int(math.Floor(bounds.minX)))
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lastPixelX := min(width, int(math.Ceil(bounds.maxX)))
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firstBlockX := firstPixelX / 6 * 6
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lastBlockX := min(width, (lastPixelX+5)/6*6)
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firstY := max(0, int(math.Floor(bounds.minY)))
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lastY := min(height, int(math.Ceil(bounds.maxY)))
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stride := V210LineSize(width)
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for y := firstY; y < lastY; y++ {
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for x := firstBlockX; x < lastBlockX; x += 6 {
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var pixels [6]YCbCr10
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for i := range pixels {
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px := x + i
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color := baseColor(px, y, width, height)
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if bounds.contains(px, y) {
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color = invertStudioRange(color)
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}
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pixels[i] = color
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}
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offset := y*stride + x/6*16
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packV210Block(dst[offset:offset+16], pixels)
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}
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}
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return nil
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}
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func invertStudioRange(color YCbCr10) YCbCr10 {
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return YCbCr10{
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Y: 1004 - color.Y,
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Cb: 1024 - color.Cb,
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Cr: 1024 - color.Cr,
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}
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}
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