302 lines
9 KiB
Go
302 lines
9 KiB
Go
// Copyright 2011 The draw2d Authors. All rights reserved.
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// created: 27/05/2011 by Laurent Le Goff
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package raster
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import (
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"image"
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"unsafe"
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)
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const (
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SUBPIXEL_SHIFT = 3
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SUBPIXEL_COUNT = 1 << SUBPIXEL_SHIFT
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)
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var SUBPIXEL_OFFSETS = SUBPIXEL_OFFSETS_SAMPLE_8
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type SUBPIXEL_DATA uint16
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type NON_ZERO_MASK_DATA_UNIT uint8
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type Rasterizer8BitsSample struct {
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MaskBuffer []SUBPIXEL_DATA
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WindingBuffer []NON_ZERO_MASK_DATA_UNIT
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Width int
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BufferWidth int
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Height int
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ClipBound [4]float64
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RemappingMatrix [6]float64
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}
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/* width and height define the maximum output size for the filler.
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* The filler will output to larger bitmaps as well, but the output will
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* be cropped.
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*/
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func NewRasterizer8BitsSample(width, height int) *Rasterizer8BitsSample {
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var r Rasterizer8BitsSample
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// Scale the coordinates by SUBPIXEL_COUNT in vertical direction
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// The sampling point for the sub-pixel is at the top right corner. This
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// adjustment moves it to the pixel center.
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r.RemappingMatrix = [6]float64{1, 0, 0, SUBPIXEL_COUNT, 0.5 / SUBPIXEL_COUNT, -0.5 * SUBPIXEL_COUNT}
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r.Width = width
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r.Height = height
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// The buffer used for filling needs to be one pixel wider than the bitmap.
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// This is because the end flag that turns the fill of is the first pixel
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// after the actually drawn edge.
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r.BufferWidth = width + 1
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r.MaskBuffer = make([]SUBPIXEL_DATA, r.BufferWidth*height)
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r.WindingBuffer = make([]NON_ZERO_MASK_DATA_UNIT, r.BufferWidth*height*SUBPIXEL_COUNT)
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r.ClipBound = clip(0, 0, width, height, SUBPIXEL_COUNT)
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return &r
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}
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func clip(x, y, width, height, scale int) [4]float64 {
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var clipBound [4]float64
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offset := 0.99 / float64(scale)
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clipBound[0] = float64(x) + offset
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clipBound[2] = float64(x+width) - offset
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clipBound[1] = float64(y * scale)
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clipBound[3] = float64((y + height) * scale)
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return clipBound
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}
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func intersect(r1, r2 [4]float64) [4]float64 {
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if r1[0] < r2[0] {
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r1[0] = r2[0]
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}
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if r1[2] > r2[2] {
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r1[2] = r2[2]
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}
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if r1[0] > r1[2] {
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r1[0] = r1[2]
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}
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if r1[1] < r2[1] {
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r1[1] = r2[1]
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}
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if r1[3] > r2[3] {
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r1[3] = r2[3]
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}
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if r1[1] > r1[3] {
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r1[1] = r1[3]
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}
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return r1
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}
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func (r *Rasterizer8BitsSample) RenderEvenOdd(img *image.RGBA, color *image.RGBAColor, polygon *Polygon, tr [6]float64) {
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// memset 0 the mask buffer
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r.MaskBuffer = make([]SUBPIXEL_DATA, r.BufferWidth*r.Height)
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// inline matrix multiplication
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transform := [6]float64{
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tr[0]*r.RemappingMatrix[0] + tr[1]*r.RemappingMatrix[2],
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tr[1]*r.RemappingMatrix[3] + tr[0]*r.RemappingMatrix[1],
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tr[2]*r.RemappingMatrix[0] + tr[3]*r.RemappingMatrix[2],
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tr[3]*r.RemappingMatrix[3] + tr[2]*r.RemappingMatrix[1],
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tr[4]*r.RemappingMatrix[0] + tr[5]*r.RemappingMatrix[2] + r.RemappingMatrix[4],
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tr[5]*r.RemappingMatrix[3] + tr[4]*r.RemappingMatrix[1] + r.RemappingMatrix[5],
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}
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clipRect := clip(img.Bounds().Min.X, img.Bounds().Min.Y, img.Bounds().Dx(), img.Bounds().Dy(), SUBPIXEL_COUNT)
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clipRect = intersect(clipRect, r.ClipBound)
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p := 0
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l := len(*polygon) / 2
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var edges [32]PolygonEdge
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for p < l {
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edgeCount := polygon.getEdges(p, 16, edges[:], transform, clipRect)
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for k := 0; k < edgeCount; k++ {
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r.addEvenOddEdge(&edges[k])
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}
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p += 16
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}
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r.fillEvenOdd(img, color, clipRect)
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}
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//! Adds an edge to be used with even-odd fill.
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func (r *Rasterizer8BitsSample) addEvenOddEdge(edge *PolygonEdge) {
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x := edge.X
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slope := edge.Slope
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var ySub, mask SUBPIXEL_DATA
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var xp, yLine int
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for y := edge.FirstLine; y <= edge.LastLine; y++ {
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ySub = SUBPIXEL_DATA(y & (SUBPIXEL_COUNT - 1))
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xp = int(x + SUBPIXEL_OFFSETS[ySub])
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mask = SUBPIXEL_DATA(1 << ySub)
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yLine = y >> SUBPIXEL_SHIFT
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r.MaskBuffer[yLine*r.BufferWidth+xp] ^= mask
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x += slope
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}
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}
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// Renders the mask to the canvas with even-odd fill.
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func (r *Rasterizer8BitsSample) fillEvenOdd(img *image.RGBA, color *image.RGBAColor, clipBound [4]float64) {
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var x, y uint32
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minX := uint32(clipBound[0])
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maxX := uint32(clipBound[2])
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minY := uint32(clipBound[1]) >> SUBPIXEL_SHIFT
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maxY := uint32(clipBound[3]) >> SUBPIXEL_SHIFT
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//pixColor := (uint32(color.R) << 24) | (uint32(color.G) << 16) | (uint32(color.B) << 8) | uint32(color.A)
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pixColor := (*uint32)(unsafe.Pointer(color))
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cs1 := *pixColor & 0xff00ff
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cs2 := *pixColor >> 8 & 0xff00ff
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stride := uint32(img.Stride)
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var mask SUBPIXEL_DATA
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for y = minY; y < maxY; y++ {
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tp := img.Pix[y*stride:]
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mask = 0
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for x = minX; x <= maxX; x++ {
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p := (*uint32)(unsafe.Pointer(&tp[x]))
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mask ^= r.MaskBuffer[y*uint32(r.BufferWidth)+x]
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// 8bits
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alpha := uint32(coverageTable[mask])
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// 16bits
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//alpha := uint32(coverageTable[mask & 0xff] + coverageTable[(mask >> 8) & 0xff])
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// 32bits
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//alpha := uint32(coverageTable[mask & 0xff] + coverageTable[(mask >> 8) & 0xff] + coverageTable[(mask >> 16) & 0xff] + coverageTable[(mask >> 24) & 0xff])
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// alpha is in range of 0 to SUBPIXEL_COUNT
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invAlpha := uint32(SUBPIXEL_COUNT) - alpha
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ct1 := *p & 0xff00ff * invAlpha
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ct2 := *p >> 8 & 0xff00ff * invAlpha
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ct1 = (ct1 + cs1*alpha) >> SUBPIXEL_SHIFT & 0xff00ff
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ct2 = (ct2 + cs2*alpha) << (8 - SUBPIXEL_SHIFT) & 0xff00ff00
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*p = ct1 + ct2
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}
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}
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}
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/*
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* Renders the polygon with non-zero winding fill.
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* param aTarget the target bitmap.
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* param aPolygon the polygon to render.
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* param aColor the color to be used for rendering.
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* param aTransformation the transformation matrix.
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*/
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func (r *Rasterizer8BitsSample) RenderNonZeroWinding(img *image.RGBA, color *image.RGBAColor, polygon *Polygon, tr [6]float64) {
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r.MaskBuffer = make([]SUBPIXEL_DATA, r.BufferWidth*r.Height)
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r.WindingBuffer = make([]NON_ZERO_MASK_DATA_UNIT, r.BufferWidth*r.Height*SUBPIXEL_COUNT)
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// inline matrix multiplication
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transform := [6]float64{
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tr[0]*r.RemappingMatrix[0] + tr[1]*r.RemappingMatrix[2],
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tr[1]*r.RemappingMatrix[3] + tr[0]*r.RemappingMatrix[1],
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tr[2]*r.RemappingMatrix[0] + tr[3]*r.RemappingMatrix[2],
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tr[3]*r.RemappingMatrix[3] + tr[2]*r.RemappingMatrix[1],
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tr[4]*r.RemappingMatrix[0] + tr[5]*r.RemappingMatrix[2] + r.RemappingMatrix[4],
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tr[5]*r.RemappingMatrix[3] + tr[4]*r.RemappingMatrix[1] + r.RemappingMatrix[5],
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}
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clipRect := clip(img.Bounds().Min.X, img.Bounds().Min.Y, img.Bounds().Dx(), img.Bounds().Dy(), SUBPIXEL_COUNT)
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clipRect = intersect(clipRect, r.ClipBound)
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p := 0
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l := len(*polygon) / 2
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var edges [32]PolygonEdge
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for p < l {
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edgeCount := polygon.getEdges(p, 16, edges[:], transform, clipRect)
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for k := 0; k < edgeCount; k++ {
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r.addNonZeroEdge(&edges[k])
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}
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p += 16
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}
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r.fillNonZero(img, color, clipRect)
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}
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//! Adds an edge to be used with non-zero winding fill.
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func (r *Rasterizer8BitsSample) addNonZeroEdge(edge *PolygonEdge) {
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x := edge.X
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slope := edge.Slope
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var ySub, mask SUBPIXEL_DATA
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var xp, yLine int
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winding := NON_ZERO_MASK_DATA_UNIT(edge.Winding)
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for y := edge.FirstLine; y <= edge.LastLine; y++ {
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ySub = SUBPIXEL_DATA(y & (SUBPIXEL_COUNT - 1))
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xp = int(x + SUBPIXEL_OFFSETS[ySub])
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mask = SUBPIXEL_DATA(1 << ySub)
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yLine = y >> SUBPIXEL_SHIFT
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r.MaskBuffer[yLine*r.BufferWidth+xp] |= mask
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r.WindingBuffer[(yLine*r.BufferWidth+xp)*SUBPIXEL_COUNT+int(ySub)] += winding
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x += slope
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}
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}
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//! Renders the mask to the canvas with non-zero winding fill.
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func (r *Rasterizer8BitsSample) fillNonZero(img *image.RGBA, color *image.RGBAColor, clipBound [4]float64) {
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var x, y uint32
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minX := uint32(clipBound[0])
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maxX := uint32(clipBound[2])
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minY := uint32(clipBound[1]) >> SUBPIXEL_SHIFT
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maxY := uint32(clipBound[3]) >> SUBPIXEL_SHIFT
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//pixColor := (uint32(color.R) << 24) | (uint32(color.G) << 16) | (uint32(color.B) << 8) | uint32(color.A)
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pixColor := (*uint32)(unsafe.Pointer(color))
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cs1 := *pixColor & 0xff00ff
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cs2 := *pixColor >> 8 & 0xff00ff
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stride := uint32(img.Stride)
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var mask SUBPIXEL_DATA
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var n uint32
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var values [SUBPIXEL_COUNT]NON_ZERO_MASK_DATA_UNIT
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for n = 0; n < SUBPIXEL_COUNT; n++ {
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values[n] = 0
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}
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for y = minY; y < maxY; y++ {
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tp := img.Pix[y*stride:]
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mask = 0
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for x = minX; x <= maxX; x++ {
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p := (*uint32)(unsafe.Pointer(&tp[x]))
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temp := r.MaskBuffer[y*uint32(r.BufferWidth)+x]
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if temp != 0 {
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var bit SUBPIXEL_DATA = 1
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for n = 0; n < SUBPIXEL_COUNT; n++ {
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if temp&bit != 0 {
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t := values[n]
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values[n] += r.WindingBuffer[(y*uint32(r.BufferWidth)+x)*SUBPIXEL_COUNT+n]
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if (t == 0 || values[n] == 0) && t != values[n] {
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mask ^= bit
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}
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}
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bit <<= 1
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}
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}
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// 8bits
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alpha := uint32(coverageTable[mask])
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// 16bits
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//alpha := uint32(coverageTable[mask & 0xff] + coverageTable[(mask >> 8) & 0xff])
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// 32bits
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//alpha := uint32(coverageTable[mask & 0xff] + coverageTable[(mask >> 8) & 0xff] + coverageTable[(mask >> 16) & 0xff] + coverageTable[(mask >> 24) & 0xff])
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// alpha is in range of 0 to SUBPIXEL_COUNT
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invAlpha := uint32(SUBPIXEL_COUNT) - alpha
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ct1 := *p & 0xff00ff * invAlpha
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ct2 := *p >> 8 & 0xff00ff * invAlpha
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ct1 = (ct1 + cs1*alpha) >> SUBPIXEL_SHIFT & 0xff00ff
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ct2 = (ct2 + cs2*alpha) << (8 - SUBPIXEL_SHIFT) & 0xff00ff00
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*p = ct1 + ct2
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}
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}
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}
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