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Unified Diff: src/core/SkScan_AAAPath.cpp

Issue 2393643002: Resubmit issue 2221103002 to fix the iOS build by declaring the flag in (Closed)
Patch Set: Created 4 years, 2 months ago
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Index: src/core/SkScan_AAAPath.cpp
diff --git a/src/core/SkScan_AAAPath.cpp b/src/core/SkScan_AAAPath.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e5b8c57d5fa9366ef44e7c04d10093a726c6ccc7
--- /dev/null
+++ b/src/core/SkScan_AAAPath.cpp
@@ -0,0 +1,1279 @@
+/*
+ * Copyright 2016 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkAntiRun.h"
+#include "SkBlitter.h"
+#include "SkEdge.h"
+#include "SkAnalyticEdge.h"
+#include "SkEdgeBuilder.h"
+#include "SkGeometry.h"
+#include "SkPath.h"
+#include "SkQuadClipper.h"
+#include "SkRasterClip.h"
+#include "SkRegion.h"
+#include "SkScan.h"
+#include "SkScanPriv.h"
+#include "SkTemplates.h"
+#include "SkTSort.h"
+#include "SkUtils.h"
+
+///////////////////////////////////////////////////////////////////////////////
+
+/*
+
+The following is a high-level overview of our analytic anti-aliasing
+algorithm. We consider a path as a collection of line segments, as
+quadratic/cubic curves are converted to small line segments. Without loss of
+generality, let's assume that the draw region is [0, W] x [0, H].
+
+Our algorithm is based on horizontal scan lines (y = c_i) as the previous
+sampling-based algorithm did. However, our algorithm uses non-equal-spaced
+scan lines, while the previous method always uses equal-spaced scan lines,
+such as (y = 1/2 + 0, 1/2 + 1, 1/2 + 2, ...) in the previous non-AA algorithm,
+and (y = 1/8 + 1/4, 1/8 + 2/4, 1/8 + 3/4, ...) in the previous
+16-supersampling AA algorithm.
+
+Our algorithm contains scan lines y = c_i for c_i that is either:
+
+1. an integer between [0, H]
+
+2. the y value of a line segment endpoint
+
+3. the y value of an intersection of two line segments
+
+For two consecutive scan lines y = c_i, y = c_{i+1}, we analytically computes
+the coverage of this horizontal strip of our path on each pixel. This can be
+done very efficiently because the strip of our path now only consists of
+trapezoids whose top and bottom edges are y = c_i, y = c_{i+1} (this includes
+rectangles and triangles as special cases).
+
+We now describe how the coverage of single pixel is computed against such a
+trapezoid. That coverage is essentially the intersection area of a rectangle
+(e.g., [0, 1] x [c_i, c_{i+1}]) and our trapezoid. However, that intersection
+could be complicated, as shown in the example region A below:
+
++-----------\----+
+| \ C|
+| \ |
+\ \ |
+|\ A \|
+| \ \
+| \ |
+| B \ |
++----\-----------+
+
+However, we don't have to compute the area of A directly. Instead, we can
+compute the excluded area, which are B and C, quite easily, because they're
+just triangles. In fact, we can prove that an excluded region (take B as an
+example) is either itself a simple trapezoid (including rectangles, triangles,
+and empty regions), or its opposite (the opposite of B is A + C) is a simple
+trapezoid. In any case, we can compute its area efficiently.
+
+In summary, our algorithm has a higher quality because it generates ground-
+truth coverages analytically. It is also faster because it has much fewer
+unnessasary horizontal scan lines. For example, given a triangle path, the
+number of scan lines in our algorithm is only about 3 + H while the
+16-supersampling algorithm has about 4H scan lines.
+
+*/
+
+///////////////////////////////////////////////////////////////////////////////
+
+inline void addAlpha(SkAlpha& alpha, SkAlpha delta) {
+ SkASSERT(alpha + (int)delta <= 0xFF);
+ alpha += delta;
+}
+
+class AdditiveBlitter : public SkBlitter {
+public:
+ virtual ~AdditiveBlitter() {}
+
+ virtual SkBlitter* getRealBlitter(bool forceRealBlitter = false) = 0;
+
+ virtual void blitAntiH(int x, int y, const SkAlpha antialias[], int len) = 0;
+ virtual void blitAntiH(int x, int y, const SkAlpha alpha) = 0;
+ virtual void blitAntiH(int x, int y, int width, const SkAlpha alpha) = 0;
+
+ void blitAntiH(int x, int y, const SkAlpha antialias[], const int16_t runs[]) override {
+ SkDEBUGFAIL("Please call real blitter's blitAntiH instead.");
+ }
+
+ void blitV(int x, int y, int height, SkAlpha alpha) override {
+ SkDEBUGFAIL("Please call real blitter's blitV instead.");
+ }
+
+ void blitH(int x, int y, int width) override {
+ SkDEBUGFAIL("Please call real blitter's blitH instead.");
+ }
+
+ void blitRect(int x, int y, int width, int height) override {
+ SkDEBUGFAIL("Please call real blitter's blitRect instead.");
+ }
+
+ void blitAntiRect(int x, int y, int width, int height,
+ SkAlpha leftAlpha, SkAlpha rightAlpha) override {
+ SkDEBUGFAIL("Please call real blitter's blitAntiRect instead.");
+ }
+
+ virtual int getWidth() = 0;
+};
+
+// We need this mask blitter because it significantly accelerates small path filling.
+class MaskAdditiveBlitter : public AdditiveBlitter {
+public:
+ MaskAdditiveBlitter(SkBlitter* realBlitter, const SkIRect& ir, const SkRegion& clip,
+ bool isInverse);
+ ~MaskAdditiveBlitter() {
+ fRealBlitter->blitMask(fMask, fClipRect);
+ }
+
+ // Most of the time, we still consider this mask blitter as the real blitter
+ // so we can accelerate blitRect and others. But sometimes we want to return
+ // the absolute real blitter (e.g., when we fall back to the old code path).
+ SkBlitter* getRealBlitter(bool forceRealBlitter) override {
+ return forceRealBlitter ? fRealBlitter : this;
+ }
+
+ // Virtual function is slow. So don't use this. Directly add alpha to the mask instead.
+ void blitAntiH(int x, int y, const SkAlpha antialias[], int len) override;
+
+ // Allowing following methods are used to blit rectangles during aaa_walk_convex_edges
+ // Since there aren't many rectangles, we can still break the slow speed of virtual functions.
+ void blitAntiH(int x, int y, const SkAlpha alpha) override;
+ void blitAntiH(int x, int y, int width, const SkAlpha alpha) override;
+ void blitV(int x, int y, int height, SkAlpha alpha) override;
+ void blitRect(int x, int y, int width, int height) override;
+ void blitAntiRect(int x, int y, int width, int height,
+ SkAlpha leftAlpha, SkAlpha rightAlpha) override;
+
+ int getWidth() override { return fClipRect.width(); }
+
+ static bool canHandleRect(const SkIRect& bounds) {
+ int width = bounds.width();
+ int64_t rb = SkAlign4(width);
+ // use 64bits to detect overflow
+ int64_t storage = rb * bounds.height();
+
+ return (width <= MaskAdditiveBlitter::kMAX_WIDTH) &&
+ (storage <= MaskAdditiveBlitter::kMAX_STORAGE);
+ }
+
+ // Return a pointer where pointer[x] corresonds to the alpha of (x, y)
+ inline uint8_t* getRow(int y) {
+ if (y != fY) {
+ fY = y;
+ fRow = fMask.fImage + (y - fMask.fBounds.fTop) * fMask.fRowBytes - fMask.fBounds.fLeft;
+ }
+ return fRow;
+ }
+
+private:
+ // so we don't try to do very wide things, where the RLE blitter would be faster
+ static const int kMAX_WIDTH = 32;
+ static const int kMAX_STORAGE = 1024;
+
+ SkBlitter* fRealBlitter;
+ SkMask fMask;
+ SkIRect fClipRect;
+ // we add 2 because we can write 1 extra byte at either end due to precision error
+ uint32_t fStorage[(kMAX_STORAGE >> 2) + 2];
+
+ uint8_t* fRow;
+ int fY;
+};
+
+MaskAdditiveBlitter::MaskAdditiveBlitter(SkBlitter* realBlitter, const SkIRect& ir, const SkRegion& clip,
+ bool isInverse) {
+ SkASSERT(canHandleRect(ir));
+ SkASSERT(!isInverse);
+
+ fRealBlitter = realBlitter;
+
+ fMask.fImage = (uint8_t*)fStorage + 1; // There's 1 extra byte at either end of fStorage
+ fMask.fBounds = ir;
+ fMask.fRowBytes = ir.width();
+ fMask.fFormat = SkMask::kA8_Format;
+
+ fY = ir.fTop - 1;
+ fRow = nullptr;
+
+ fClipRect = ir;
+ if (!fClipRect.intersect(clip.getBounds())) {
+ SkASSERT(0);
+ fClipRect.setEmpty();
+ }
+
+ memset(fStorage, 0, fMask.fBounds.height() * fMask.fRowBytes + 2);
+}
+
+void MaskAdditiveBlitter::blitAntiH(int x, int y, const SkAlpha antialias[], int len) {
+ SkFAIL("Don't use this; directly add alphas to the mask.");
+}
+
+void MaskAdditiveBlitter::blitAntiH(int x, int y, const SkAlpha alpha) {
+ SkASSERT(x >= fMask.fBounds.fLeft -1);
+ addAlpha(this->getRow(y)[x], alpha);
+}
+
+void MaskAdditiveBlitter::blitAntiH(int x, int y, int width, const SkAlpha alpha) {
+ SkASSERT(x >= fMask.fBounds.fLeft -1);
+ uint8_t* row = this->getRow(y);
+ for (int i=0; i<width; i++) {
+ addAlpha(row[x + i], alpha);
+ }
+}
+
+void MaskAdditiveBlitter::blitV(int x, int y, int height, SkAlpha alpha) {
+ if (alpha == 0) {
+ return;
+ }
+ SkASSERT(x >= fMask.fBounds.fLeft -1);
+ // This must be called as if this is a real blitter.
+ // So we directly set alpha rather than adding it.
+ uint8_t* row = this->getRow(y);
+ for (int i=0; i<height; i++) {
+ row[x] = alpha;
+ row += fMask.fRowBytes;
+ }
+}
+
+void MaskAdditiveBlitter::blitRect(int x, int y, int width, int height) {
+ SkASSERT(x >= fMask.fBounds.fLeft -1);
+ // This must be called as if this is a real blitter.
+ // So we directly set alpha rather than adding it.
+ uint8_t* row = this->getRow(y);
+ for (int i=0; i<height; i++) {
+ memset(row + x, 0xFF, width);
+ row += fMask.fRowBytes;
+ }
+}
+
+void MaskAdditiveBlitter::blitAntiRect(int x, int y, int width, int height,
+ SkAlpha leftAlpha, SkAlpha rightAlpha) {
+ blitV(x, y, height, leftAlpha);
+ blitV(x + 1 + width, y, height, rightAlpha);
+ blitRect(x + 1, y, width, height);
+}
+
+class RunBasedAdditiveBlitter : public AdditiveBlitter {
+public:
+ RunBasedAdditiveBlitter(SkBlitter* realBlitter, const SkIRect& ir, const SkRegion& clip,
+ bool isInverse);
+ ~RunBasedAdditiveBlitter();
+
+ SkBlitter* getRealBlitter(bool forceRealBlitter) override;
+
+ void blitAntiH(int x, int y, const SkAlpha antialias[], int len) override;
+ void blitAntiH(int x, int y, const SkAlpha alpha) override;
+ void blitAntiH(int x, int y, int width, const SkAlpha alpha) override;
+
+ int getWidth() override;
+
+private:
+ SkBlitter* fRealBlitter;
+
+ /// Current y coordinate
+ int fCurrY;
+ /// Widest row of region to be blitted
+ int fWidth;
+ /// Leftmost x coordinate in any row
+ int fLeft;
+ /// Initial y coordinate (top of bounds).
+ int fTop;
+
+ // The next three variables are used to track a circular buffer that
+ // contains the values used in SkAlphaRuns. These variables should only
+ // ever be updated in advanceRuns(), and fRuns should always point to
+ // a valid SkAlphaRuns...
+ int fRunsToBuffer;
+ void* fRunsBuffer;
+ int fCurrentRun;
+ SkAlphaRuns fRuns;
+
+ int fOffsetX;
+
+ inline bool check(int x, int width) {
+ #ifdef SK_DEBUG
+ if (x < 0 || x + width > fWidth) {
+ SkDebugf("Ignore x = %d, width = %d\n", x, width);
+ }
+ #endif
+ return (x >= 0 && x + width <= fWidth);
+ }
+
+ // extra one to store the zero at the end
+ inline int getRunsSz() const { return (fWidth + 1 + (fWidth + 2)/2) * sizeof(int16_t); }
+
+ // This function updates the fRuns variable to point to the next buffer space
+ // with adequate storage for a SkAlphaRuns. It mostly just advances fCurrentRun
+ // and resets fRuns to point to an empty scanline.
+ inline void advanceRuns() {
+ const size_t kRunsSz = this->getRunsSz();
+ fCurrentRun = (fCurrentRun + 1) % fRunsToBuffer;
+ fRuns.fRuns = reinterpret_cast<int16_t*>(
+ reinterpret_cast<uint8_t*>(fRunsBuffer) + fCurrentRun * kRunsSz);
+ fRuns.fAlpha = reinterpret_cast<SkAlpha*>(fRuns.fRuns + fWidth + 1);
+ fRuns.reset(fWidth);
+ }
+
+ // Blitting 0xFF and 0 is much faster so we snap alphas close to them
+ inline SkAlpha snapAlpha(SkAlpha alpha) {
+ return alpha > 247 ? 0xFF : alpha < 8 ? 0 : alpha;
+ }
+
+ inline void flush() {
+ if (fCurrY >= fTop) {
+ SkASSERT(fCurrentRun < fRunsToBuffer);
+ for (int x = 0; fRuns.fRuns[x]; x += fRuns.fRuns[x]) {
+ // It seems that blitting 255 or 0 is much faster than blitting 254 or 1
+ fRuns.fAlpha[x] = snapAlpha(fRuns.fAlpha[x]);
+ }
+ if (!fRuns.empty()) {
+ // SkDEBUGCODE(fRuns.dump();)
+ fRealBlitter->blitAntiH(fLeft, fCurrY, fRuns.fAlpha, fRuns.fRuns);
+ this->advanceRuns();
+ fOffsetX = 0;
+ }
+ fCurrY = fTop - 1;
+ }
+ }
+
+ inline void checkY(int y) {
+ if (y != fCurrY) {
+ this->flush();
+ fCurrY = y;
+ }
+ }
+};
+
+RunBasedAdditiveBlitter::RunBasedAdditiveBlitter(SkBlitter* realBlitter, const SkIRect& ir, const SkRegion& clip,
+ bool isInverse) {
+ fRealBlitter = realBlitter;
+
+ SkIRect sectBounds;
+ if (isInverse) {
+ // We use the clip bounds instead of the ir, since we may be asked to
+ //draw outside of the rect when we're a inverse filltype
+ sectBounds = clip.getBounds();
+ } else {
+ if (!sectBounds.intersect(ir, clip.getBounds())) {
+ sectBounds.setEmpty();
+ }
+ }
+
+ const int left = sectBounds.left();
+ const int right = sectBounds.right();
+
+ fLeft = left;
+ fWidth = right - left;
+ fTop = sectBounds.top();
+ fCurrY = fTop - 1;
+
+ fRunsToBuffer = realBlitter->requestRowsPreserved();
+ fRunsBuffer = realBlitter->allocBlitMemory(fRunsToBuffer * this->getRunsSz());
+ fCurrentRun = -1;
+
+ this->advanceRuns();
+
+ fOffsetX = 0;
+}
+
+RunBasedAdditiveBlitter::~RunBasedAdditiveBlitter() {
+ this->flush();
+}
+
+SkBlitter* RunBasedAdditiveBlitter::getRealBlitter(bool forceRealBlitter) {
+ return fRealBlitter;
+}
+
+void RunBasedAdditiveBlitter::blitAntiH(int x, int y, const SkAlpha antialias[], int len) {
+ checkY(y);
+ x -= fLeft;
+
+ if (x < 0) {
+ len += x;
+ antialias -= x;
+ x = 0;
+ }
+ len = SkTMin(len, fWidth - x);
+ SkASSERT(check(x, len));
+
+ if (x < fOffsetX) {
+ fOffsetX = 0;
+ }
+
+ fOffsetX = fRuns.add(x, 0, len, 0, 0, fOffsetX); // Break the run
+ for (int i = 0; i < len; i += fRuns.fRuns[x + i]) {
+ for (int j = 1; j < fRuns.fRuns[x + i]; j++) {
+ fRuns.fRuns[x + i + j] = 1;
+ fRuns.fAlpha[x + i + j] = fRuns.fAlpha[x + i];
+ }
+ fRuns.fRuns[x + i] = 1;
+ }
+ for (int i=0; i<len; i++) {
+ addAlpha(fRuns.fAlpha[x + i], antialias[i]);
+ }
+}
+void RunBasedAdditiveBlitter::blitAntiH(int x, int y, const SkAlpha alpha) {
+ checkY(y);
+ x -= fLeft;
+
+ if (x < fOffsetX) {
+ fOffsetX = 0;
+ }
+
+ if (this->check(x, 1)) {
+ fOffsetX = fRuns.add(x, 0, 1, 0, alpha, fOffsetX);
+ }
+}
+
+void RunBasedAdditiveBlitter::blitAntiH(int x, int y, int width, const SkAlpha alpha) {
+ checkY(y);
+ x -= fLeft;
+
+ if (x < fOffsetX) {
+ fOffsetX = 0;
+ }
+
+ if (this->check(x, width)) {
+ fOffsetX = fRuns.add(x, 0, width, 0, alpha, fOffsetX);
+ }
+}
+
+int RunBasedAdditiveBlitter::getWidth() { return fWidth; }
+
+///////////////////////////////////////////////////////////////////////////////
+
+// Return the alpha of a trapezoid whose height is 1
+static inline SkAlpha trapezoidToAlpha(SkFixed l1, SkFixed l2) {
+ SkASSERT(l1 >= 0 && l2 >= 0);
+ return ((l1 + l2) >> 9);
+}
+
+// The alpha of right-triangle (a, a*b), in 16 bits
+static inline SkFixed partialTriangleToAlpha16(SkFixed a, SkFixed b) {
+ SkASSERT(a <= SK_Fixed1);
+ // SkFixedMul_lowprec(SkFixedMul_lowprec(a, a), b) >> 1
+ // return ((((a >> 8) * (a >> 8)) >> 8) * (b >> 8)) >> 1;
+ return (a >> 11) * (a >> 11) * (b >> 11);
+}
+
+// The alpha of right-triangle (a, a*b)
+static inline SkAlpha partialTriangleToAlpha(SkFixed a, SkFixed b) {
+ return partialTriangleToAlpha16(a, b) >> 8;
+}
+
+static inline SkAlpha getPartialAlpha(SkAlpha alpha, SkFixed partialHeight) {
+ return (alpha * partialHeight) >> 16;
+}
+
+static inline SkAlpha getPartialAlpha(SkAlpha alpha, SkAlpha fullAlpha) {
+ return ((uint16_t)alpha * fullAlpha) >> 8;
+}
+
+// For SkFixed that's close to SK_Fixed1, we can't convert it to alpha by just shifting right.
+// For example, when f = SK_Fixed1, right shifting 8 will get 256, but we need 255.
+// This is rarely the problem so we'll only use this for blitting rectangles.
+static inline SkAlpha f2a(SkFixed f) {
+ SkASSERT(f <= SK_Fixed1);
+ return getPartialAlpha(0xFF, f);
+}
+
+// Suppose that line (l1, y)-(r1, y+1) intersects with (l2, y)-(r2, y+1),
+// approximate (very coarsely) the x coordinate of the intersection.
+static inline SkFixed approximateIntersection(SkFixed l1, SkFixed r1, SkFixed l2, SkFixed r2) {
+ if (l1 > r1) { SkTSwap(l1, r1); }
+ if (l2 > r2) { SkTSwap(l2, r2); }
+ return (SkTMax(l1, l2) + SkTMin(r1, r2)) >> 1;
+}
+
+// Here we always send in l < SK_Fixed1, and the first alpha we want to compute is alphas[0]
+static inline void computeAlphaAboveLine(SkAlpha* alphas, SkFixed l, SkFixed r,
+ SkFixed dY, SkAlpha fullAlpha) {
+ SkASSERT(l <= r);
+ SkASSERT(l >> 16 == 0);
+ int R = SkFixedCeilToInt(r);
+ if (R == 0) {
+ return;
+ } else if (R == 1) {
+ alphas[0] = getPartialAlpha(((R << 17) - l - r) >> 9, fullAlpha);
+ } else {
+ SkFixed first = SK_Fixed1 - l; // horizontal edge length of the left-most triangle
+ SkFixed last = r - ((R - 1) << 16); // horizontal edge length of the right-most triangle
+ SkFixed firstH = SkFixedMul_lowprec(first, dY); // vertical edge of the left-most triangle
+ alphas[0] = SkFixedMul_lowprec(first, firstH) >> 9; // triangle alpha
+ SkFixed alpha16 = firstH + (dY >> 1); // rectangle plus triangle
+ for (int i = 1; i < R - 1; i++) {
+ alphas[i] = alpha16 >> 8;
+ alpha16 += dY;
+ }
+ alphas[R - 1] = fullAlpha - partialTriangleToAlpha(last, dY);
+ }
+}
+
+// Here we always send in l < SK_Fixed1, and the first alpha we want to compute is alphas[0]
+static inline void computeAlphaBelowLine(SkAlpha* alphas, SkFixed l, SkFixed r, SkFixed dY, SkAlpha fullAlpha) {
+ SkASSERT(l <= r);
+ SkASSERT(l >> 16 == 0);
+ int R = SkFixedCeilToInt(r);
+ if (R == 0) {
+ return;
+ } else if (R == 1) {
+ alphas[0] = getPartialAlpha(trapezoidToAlpha(l, r), fullAlpha);
+ } else {
+ SkFixed first = SK_Fixed1 - l; // horizontal edge length of the left-most triangle
+ SkFixed last = r - ((R - 1) << 16); // horizontal edge length of the right-most triangle
+ SkFixed lastH = SkFixedMul_lowprec(last, dY); // vertical edge of the right-most triangle
+ alphas[R-1] = SkFixedMul_lowprec(last, lastH) >> 9; // triangle alpha
+ SkFixed alpha16 = lastH + (dY >> 1); // rectangle plus triangle
+ for (int i = R - 2; i > 0; i--) {
+ alphas[i] = alpha16 >> 8;
+ alpha16 += dY;
+ }
+ alphas[0] = fullAlpha - partialTriangleToAlpha(first, dY);
+ }
+}
+
+// Note that if fullAlpha != 0xFF, we'll multiply alpha by fullAlpha
+static inline void blit_single_alpha(AdditiveBlitter* blitter, int y, int x,
+ SkAlpha alpha, SkAlpha fullAlpha, SkAlpha* maskRow,
+ bool isUsingMask) {
+ if (isUsingMask) {
+ if (fullAlpha == 0xFF) {
+ maskRow[x] = alpha;
+ } else {
+ addAlpha(maskRow[x], getPartialAlpha(alpha, fullAlpha));
+ }
+ } else {
+ if (fullAlpha == 0xFF) {
+ blitter->getRealBlitter()->blitV(x, y, 1, alpha);
+ } else {
+ blitter->blitAntiH(x, y, getPartialAlpha(alpha, fullAlpha));
+ }
+ }
+}
+
+static inline void blit_two_alphas(AdditiveBlitter* blitter, int y, int x,
+ SkAlpha a1, SkAlpha a2, SkAlpha fullAlpha, SkAlpha* maskRow,
+ bool isUsingMask) {
+ if (isUsingMask) {
+ addAlpha(maskRow[x], a1);
+ addAlpha(maskRow[x + 1], a2);
+ } else {
+ if (fullAlpha == 0xFF) {
+ blitter->getRealBlitter()->blitV(x, y, 1, a1);
+ blitter->getRealBlitter()->blitV(x + 1, y, 1, a2);
+ } else {
+ blitter->blitAntiH(x, y, a1);
+ blitter->blitAntiH(x + 1, y, a2);
+ }
+ }
+}
+
+// It's important that this is inline. Otherwise it'll be much slower.
+static SK_ALWAYS_INLINE void blit_full_alpha(AdditiveBlitter* blitter, int y, int x, int len,
+ SkAlpha fullAlpha, SkAlpha* maskRow, bool isUsingMask) {
+ if (isUsingMask) {
+ for (int i=0; i<len; i++) {
+ addAlpha(maskRow[x + i], fullAlpha);
+ }
+ } else {
+ if (fullAlpha == 0xFF) {
+ blitter->getRealBlitter()->blitH(x, y, len);
+ } else {
+ blitter->blitAntiH(x, y, len, fullAlpha);
+ }
+ }
+}
+
+static void blit_aaa_trapezoid_row(AdditiveBlitter* blitter, int y,
+ SkFixed ul, SkFixed ur, SkFixed ll, SkFixed lr,
+ SkFixed lDY, SkFixed rDY, SkAlpha fullAlpha, SkAlpha* maskRow,
+ bool isUsingMask) {
+ int L = SkFixedFloorToInt(ul), R = SkFixedCeilToInt(lr);
+ int len = R - L;
+
+ if (len == 1) {
+ SkAlpha alpha = trapezoidToAlpha(ur - ul, lr - ll);
+ blit_single_alpha(blitter, y, L, alpha, fullAlpha, maskRow, isUsingMask);
+ return;
+ }
+
+ // SkDebugf("y = %d, len = %d, ul = %f, ur = %f, ll = %f, lr = %f\n", y, len,
+ // SkFixedToFloat(ul), SkFixedToFloat(ur), SkFixedToFloat(ll), SkFixedToFloat(lr));
+
+ const int kQuickLen = 31;
+ // This is faster than SkAutoSMalloc<1024>
+ char quickMemory[(sizeof(SkAlpha) * 2 + sizeof(int16_t)) * (kQuickLen + 1)];
+ SkAlpha* alphas;
+
+ if (len <= kQuickLen) {
+ alphas = (SkAlpha*)quickMemory;
+ } else {
+ alphas = new SkAlpha[(len + 1) * (sizeof(SkAlpha) * 2 + sizeof(int16_t))];
+ }
+
+ SkAlpha* tempAlphas = alphas + len + 1;
+ int16_t* runs = (int16_t*)(alphas + (len + 1) * 2);
+
+ for (int i = 0; i < len; i++) {
+ runs[i] = 1;
+ alphas[i] = fullAlpha;
+ }
+ runs[len] = 0;
+
+ int uL = SkFixedFloorToInt(ul);
+ int lL = SkFixedCeilToInt(ll);
+ if (uL + 2 == lL) { // We only need to compute two triangles, accelerate this special case
+ SkFixed first = (uL << 16) + SK_Fixed1 - ul;
+ SkFixed second = ll - ul - first;
+ SkAlpha a1 = fullAlpha - partialTriangleToAlpha(first, lDY);
+ SkAlpha a2 = partialTriangleToAlpha(second, lDY);
+ alphas[0] = alphas[0] > a1 ? alphas[0] - a1 : 0;
+ alphas[1] = alphas[1] > a2 ? alphas[1] - a2 : 0;
+ } else {
+ computeAlphaBelowLine(tempAlphas + uL - L, ul - (uL << 16), ll - (uL << 16),
+ lDY, fullAlpha);
+ for (int i = uL; i < lL; i++) {
+ if (alphas[i - L] > tempAlphas[i - L]) {
+ alphas[i - L] -= tempAlphas[i - L];
+ } else {
+ alphas[i - L] = 0;
+ }
+ }
+ }
+
+ int uR = SkFixedFloorToInt(ur);
+ int lR = SkFixedCeilToInt(lr);
+ if (uR + 2 == lR) { // We only need to compute two triangles, accelerate this special case
+ SkFixed first = (uR << 16) + SK_Fixed1 - ur;
+ SkFixed second = lr - ur - first;
+ SkAlpha a1 = partialTriangleToAlpha(first, rDY);
+ SkAlpha a2 = fullAlpha - partialTriangleToAlpha(second, rDY);
+ alphas[len-2] = alphas[len-2] > a1 ? alphas[len-2] - a1 : 0;
+ alphas[len-1] = alphas[len-1] > a2 ? alphas[len-1] - a2 : 0;
+ } else {
+ computeAlphaAboveLine(tempAlphas + uR - L, ur - (uR << 16), lr - (uR << 16),
+ rDY, fullAlpha);
+ for (int i = uR; i < lR; i++) {
+ if (alphas[i - L] > tempAlphas[i - L]) {
+ alphas[i - L] -= tempAlphas[i - L];
+ } else {
+ alphas[i - L] = 0;
+ }
+ }
+ }
+
+ if (isUsingMask) {
+ for (int i=0; i<len; i++) {
+ addAlpha(maskRow[L + i], alphas[i]);
+ }
+ } else {
+ if (fullAlpha == 0xFF) { // Real blitter is faster than RunBasedAdditiveBlitter
+ blitter->getRealBlitter()->blitAntiH(L, y, alphas, runs);
+ } else {
+ blitter->blitAntiH(L, y, alphas, len);
+ }
+ }
+
+ if (len > kQuickLen) {
+ delete [] alphas;
+ }
+}
+
+static inline void blit_trapezoid_row(AdditiveBlitter* blitter, int y,
+ SkFixed ul, SkFixed ur, SkFixed ll, SkFixed lr,
+ SkFixed lDY, SkFixed rDY, SkAlpha fullAlpha,
+ SkAlpha* maskRow, bool isUsingMask) {
+ SkASSERT(lDY >= 0 && rDY >= 0); // We should only send in the absolte value
+
+ if (ul > ur) {
+#ifdef SK_DEBUG
+ SkDebugf("ul = %f > ur = %f!\n", SkFixedToFloat(ul), SkFixedToFloat(ur));
+#endif
+ return;
+ }
+
+ // Edge crosses. Approximate it. This should only happend due to precision limit,
+ // so the approximation could be very coarse.
+ if (ll > lr) {
+#ifdef SK_DEBUG
+ SkDebugf("approximate intersection: %d %f %f\n", y,
+ SkFixedToFloat(ll), SkFixedToFloat(lr));
+#endif
+ ll = lr = approximateIntersection(ul, ll, ur, lr);
+ }
+
+ if (ul == ur && ll == lr) {
+ return; // empty trapzoid
+ }
+
+ // We're going to use the left line ul-ll and the rite line ur-lr
+ // to exclude the area that's not covered by the path.
+ // Swapping (ul, ll) or (ur, lr) won't affect that exclusion
+ // so we'll do that for simplicity.
+ if (ul > ll) { SkTSwap(ul, ll); }
+ if (ur > lr) { SkTSwap(ur, lr); }
+
+ SkFixed joinLeft = SkFixedCeilToFixed(ll);
+ SkFixed joinRite = SkFixedFloorToFixed(ur);
+ if (joinLeft <= joinRite) { // There's a rect from joinLeft to joinRite that we can blit
+ if (joinLeft < joinRite) {
+ blit_full_alpha(blitter, y, joinLeft >> 16, (joinRite - joinLeft) >> 16, fullAlpha,
+ maskRow, isUsingMask);
+ }
+ if (ul < joinLeft) {
+ int len = SkFixedCeilToInt(joinLeft - ul);
+ if (len == 1) {
+ SkAlpha alpha = trapezoidToAlpha(joinLeft - ul, joinLeft - ll);
+ blit_single_alpha(blitter, y, ul >> 16, alpha, fullAlpha, maskRow, isUsingMask);
+ } else if (len == 2) {
+ SkFixed first = joinLeft - SK_Fixed1 - ul;
+ SkFixed second = ll - ul - first;
+ SkAlpha a1 = partialTriangleToAlpha(first, lDY);
+ SkAlpha a2 = fullAlpha - partialTriangleToAlpha(second, lDY);
+ blit_two_alphas(blitter, y, ul >> 16, a1, a2, fullAlpha, maskRow, isUsingMask);
+ } else {
+ blit_aaa_trapezoid_row(blitter, y, ul, joinLeft, ll, joinLeft, lDY, SK_MaxS32,
+ fullAlpha, maskRow, isUsingMask);
+ }
+ }
+ if (lr > joinRite) {
+ int len = SkFixedCeilToInt(lr - joinRite);
+ if (len == 1) {
+ SkAlpha alpha = trapezoidToAlpha(ur - joinRite, lr - joinRite);
+ blit_single_alpha(blitter, y, joinRite >> 16, alpha, fullAlpha, maskRow,
+ isUsingMask);
+ } else if (len == 2) {
+ SkFixed first = joinRite + SK_Fixed1 - ur;
+ SkFixed second = lr - ur - first;
+ SkAlpha a1 = fullAlpha - partialTriangleToAlpha(first, rDY);
+ SkAlpha a2 = partialTriangleToAlpha(second, rDY);
+ blit_two_alphas(blitter, y, joinRite >> 16, a1, a2, fullAlpha, maskRow,
+ isUsingMask);
+ } else {
+ blit_aaa_trapezoid_row(blitter, y, joinRite, ur, joinRite, lr, SK_MaxS32, rDY,
+ fullAlpha, maskRow, isUsingMask);
+ }
+ }
+ } else {
+ blit_aaa_trapezoid_row(blitter, y, ul, ur, ll, lr, lDY, rDY, fullAlpha, maskRow,
+ isUsingMask);
+ }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+static bool operator<(const SkAnalyticEdge& a, const SkAnalyticEdge& b) {
+ int valuea = a.fUpperY;
+ int valueb = b.fUpperY;
+
+ if (valuea == valueb) {
+ valuea = a.fX;
+ valueb = b.fX;
+ }
+
+ if (valuea == valueb) {
+ valuea = a.fDX;
+ valueb = b.fDX;
+ }
+
+ return valuea < valueb;
+}
+
+static SkAnalyticEdge* sort_edges(SkAnalyticEdge* list[], int count, SkAnalyticEdge** last) {
+ SkTQSort(list, list + count - 1);
+
+ // now make the edges linked in sorted order
+ for (int i = 1; i < count; i++) {
+ list[i - 1]->fNext = list[i];
+ list[i]->fPrev = list[i - 1];
+ }
+
+ *last = list[count - 1];
+ return list[0];
+}
+
+#ifdef SK_DEBUG
+ static void validate_sort(const SkAnalyticEdge* edge) {
+ SkFixed y = SkIntToFixed(-32768);
+
+ while (edge->fUpperY != SK_MaxS32) {
+ edge->validate();
+ SkASSERT(y <= edge->fUpperY);
+
+ y = edge->fUpperY;
+ edge = (SkAnalyticEdge*)edge->fNext;
+ }
+ }
+#else
+ #define validate_sort(edge)
+#endif
+
+// return true if we're done with this edge
+static bool update_edge(SkAnalyticEdge* edge, SkFixed last_y) {
+ if (last_y >= edge->fLowerY) {
+ if (edge->fCurveCount < 0) {
+ if (static_cast<SkAnalyticCubicEdge*>(edge)->updateCubic()) {
+ return false;
+ }
+ } else if (edge->fCurveCount > 0) {
+ if (static_cast<SkAnalyticQuadraticEdge*>(edge)->updateQuadratic()) {
+ return false;
+ }
+ }
+ return true;
+ }
+ SkASSERT(false);
+ return false;
+}
+
+// For an edge, we consider it smooth if the Dx doesn't change much, and Dy is large enough
+// For curves that are updating, the Dx is not changing much if fQDx/fCDx and fQDy/fCDy are
+// relatively large compared to fQDDx/QCDDx and fQDDy/fCDDy
+static inline bool isSmoothEnough(SkAnalyticEdge* thisEdge, SkAnalyticEdge* nextEdge, int stop_y) {
+ if (thisEdge->fCurveCount < 0) {
+ const SkCubicEdge& cEdge = static_cast<SkAnalyticCubicEdge*>(thisEdge)->fCEdge;
+ int ddshift = cEdge.fCurveShift;
+ return SkAbs32(cEdge.fCDx) >> 1 >= SkAbs32(cEdge.fCDDx) >> ddshift &&
+ SkAbs32(cEdge.fCDy) >> 1 >= SkAbs32(cEdge.fCDDy) >> ddshift &&
+ // current Dy is (fCDy - (fCDDy >> ddshift)) >> dshift
+ (cEdge.fCDy - (cEdge.fCDDy >> ddshift)) >> cEdge.fCubicDShift >= SK_Fixed1;
+ } else if (thisEdge->fCurveCount > 0) {
+ const SkQuadraticEdge& qEdge = static_cast<SkAnalyticQuadraticEdge*>(thisEdge)->fQEdge;
+ return SkAbs32(qEdge.fQDx) >> 1 >= SkAbs32(qEdge.fQDDx) &&
+ SkAbs32(qEdge.fQDy) >> 1 >= SkAbs32(qEdge.fQDDy) &&
+ // current Dy is (fQDy - fQDDy) >> shift
+ (qEdge.fQDy - qEdge.fQDDy) >> qEdge.fCurveShift
+ >= SK_Fixed1;
+ }
+ return SkAbs32(nextEdge->fDX - thisEdge->fDX) <= SK_Fixed1 && // DDx should be small
+ nextEdge->fLowerY - nextEdge->fUpperY >= SK_Fixed1; // Dy should be large
+}
+
+// Check if the leftE and riteE are changing smoothly in terms of fDX.
+// If yes, we can later skip the fractional y and directly jump to integer y.
+static inline bool isSmoothEnough(SkAnalyticEdge* leftE, SkAnalyticEdge* riteE,
+ SkAnalyticEdge* currE, int stop_y) {
+ if (currE->fUpperY >= stop_y << 16) {
+ return false; // We're at the end so we won't skip anything
+ }
+ if (leftE->fLowerY + SK_Fixed1 < riteE->fLowerY) {
+ return isSmoothEnough(leftE, currE, stop_y); // Only leftE is changing
+ } else if (leftE->fLowerY > riteE->fLowerY + SK_Fixed1) {
+ return isSmoothEnough(riteE, currE, stop_y); // Only riteE is changing
+ }
+
+ // Now both edges are changing, find the second next edge
+ SkAnalyticEdge* nextCurrE = currE->fNext;
+ if (nextCurrE->fUpperY >= stop_y << 16) { // Check if we're at the end
+ return false;
+ }
+ if (*nextCurrE < *currE) {
+ SkTSwap(currE, nextCurrE);
+ }
+ return isSmoothEnough(leftE, currE, stop_y) && isSmoothEnough(riteE, nextCurrE, stop_y);
+}
+
+static inline void aaa_walk_convex_edges(SkAnalyticEdge* prevHead, AdditiveBlitter* blitter,
+ int start_y, int stop_y, SkFixed leftBound, SkFixed riteBound,
+ bool isUsingMask) {
+ validate_sort((SkAnalyticEdge*)prevHead->fNext);
+
+ SkAnalyticEdge* leftE = (SkAnalyticEdge*) prevHead->fNext;
+ SkAnalyticEdge* riteE = (SkAnalyticEdge*) leftE->fNext;
+ SkAnalyticEdge* currE = (SkAnalyticEdge*) riteE->fNext;
+
+ SkFixed y = SkTMax(leftE->fUpperY, riteE->fUpperY);
+
+ #ifdef SK_DEBUG
+ int frac_y_cnt = 0;
+ int total_y_cnt = 0;
+ #endif
+
+ for (;;) {
+ // We have to check fLowerY first because some edges might be alone (e.g., there's only
+ // a left edge but no right edge in a given y scan line) due to precision limit.
+ while (leftE->fLowerY <= y) { // Due to smooth jump, we may pass multiple short edges
+ if (update_edge(leftE, y)) {
+ if (SkFixedFloorToInt(currE->fUpperY) >= stop_y) {
+ goto END_WALK;
+ }
+ leftE = currE;
+ currE = (SkAnalyticEdge*)currE->fNext;
+ }
+ }
+ while (riteE->fLowerY <= y) { // Due to smooth jump, we may pass multiple short edges
+ if (update_edge(riteE, y)) {
+ if (SkFixedFloorToInt(currE->fUpperY) >= stop_y) {
+ goto END_WALK;
+ }
+ riteE = currE;
+ currE = (SkAnalyticEdge*)currE->fNext;
+ }
+ }
+
+ SkASSERT(leftE);
+ SkASSERT(riteE);
+
+ // check our bottom clip
+ if (SkFixedFloorToInt(y) >= stop_y) {
+ break;
+ }
+
+ SkASSERT(SkFixedFloorToInt(leftE->fUpperY) <= stop_y);
+ SkASSERT(SkFixedFloorToInt(riteE->fUpperY) <= stop_y);
+
+ leftE->goY(y);
+ riteE->goY(y);
+
+ if (leftE->fX > riteE->fX || (leftE->fX == riteE->fX &&
+ leftE->fDX > riteE->fDX)) {
+ SkTSwap(leftE, riteE);
+ }
+
+ SkFixed local_bot_fixed = SkMin32(leftE->fLowerY, riteE->fLowerY);
+ // Skip the fractional y if edges are changing smoothly
+ if (isSmoothEnough(leftE, riteE, currE, stop_y)) {
+ local_bot_fixed = SkFixedCeilToFixed(local_bot_fixed);
+ }
+ local_bot_fixed = SkMin32(local_bot_fixed, SkIntToFixed(stop_y + 1));
+
+ SkFixed left = leftE->fX;
+ SkFixed dLeft = leftE->fDX;
+ SkFixed rite = riteE->fX;
+ SkFixed dRite = riteE->fDX;
+ if (0 == (dLeft | dRite)) {
+ int fullLeft = SkFixedCeilToInt(left);
+ int fullRite = SkFixedFloorToInt(rite);
+ SkFixed partialLeft = SkIntToFixed(fullLeft) - left;
+ SkFixed partialRite = rite - SkIntToFixed(fullRite);
+ int fullTop = SkFixedCeilToInt(y);
+ int fullBot = SkFixedFloorToInt(local_bot_fixed);
+ SkFixed partialTop = SkIntToFixed(fullTop) - y;
+ SkFixed partialBot = local_bot_fixed - SkIntToFixed(fullBot);
+ if (fullTop > fullBot) { // The rectangle is within one pixel height...
+ partialTop -= (SK_Fixed1 - partialBot);
+ partialBot = 0;
+ }
+
+ if (fullRite >= fullLeft) {
+ // Blit all full-height rows from fullTop to fullBot
+ if (fullBot > fullTop) {
+ blitter->getRealBlitter()->blitAntiRect(fullLeft - 1, fullTop,
+ fullRite - fullLeft, fullBot - fullTop,
+ f2a(partialLeft), f2a(partialRite));
+ }
+
+ if (partialTop > 0) { // blit first partial row
+ if (partialLeft > 0) {
+ blitter->blitAntiH(fullLeft - 1, fullTop - 1,
+ f2a(SkFixedMul_lowprec(partialTop, partialLeft)));
+ }
+ if (partialRite > 0) {
+ blitter->blitAntiH(fullRite, fullTop - 1,
+ f2a(SkFixedMul_lowprec(partialTop, partialRite)));
+ }
+ blitter->blitAntiH(fullLeft, fullTop - 1, fullRite - fullLeft,
+ f2a(partialTop));
+ }
+
+ if (partialBot > 0) { // blit last partial row
+ if (partialLeft > 0) {
+ blitter->blitAntiH(fullLeft - 1, fullBot,
+ f2a(SkFixedMul_lowprec(partialBot, partialLeft)));
+ }
+ if (partialRite > 0) {
+ blitter->blitAntiH(fullRite, fullBot,
+ f2a(SkFixedMul_lowprec(partialBot, partialRite)));
+ }
+ blitter->blitAntiH(fullLeft, fullBot, fullRite - fullLeft, f2a(partialBot));
+ }
+ } else { // left and rite are within the same pixel
+ if (partialTop > 0) {
+ blitter->getRealBlitter()->blitV(fullLeft - 1, fullTop - 1, 1,
+ f2a(SkFixedMul_lowprec(partialTop, rite - left)));
+ }
+ if (partialBot > 0) {
+ blitter->getRealBlitter()->blitV(fullLeft - 1, fullBot, 1,
+ f2a(SkFixedMul_lowprec(partialBot, rite - left)));
+ }
+ if (fullBot >= fullTop) {
+ blitter->getRealBlitter()->blitV(fullLeft - 1, fullTop, fullBot - fullTop,
+ f2a(rite - left));
+ }
+ }
+
+ y = local_bot_fixed;
+ } else {
+ // The following constant are used to snap X
+ // We snap X mainly for speedup (no tiny triangle) and
+ // avoiding edge cases caused by precision errors
+ const SkFixed kSnapDigit = SK_Fixed1 >> 4;
+ const SkFixed kSnapHalf = kSnapDigit >> 1;
+ const SkFixed kSnapMask = (-1 ^ (kSnapDigit - 1));
+ left += kSnapHalf; rite += kSnapHalf; // For fast rounding
+
+ // Number of blit_trapezoid_row calls we'll have
+ int count = SkFixedCeilToInt(local_bot_fixed) - SkFixedFloorToInt(y);
+ #ifdef SK_DEBUG
+ total_y_cnt += count;
+ frac_y_cnt += ((int)(y & 0xFFFF0000) != y);
+ if ((int)(y & 0xFFFF0000) != y) {
+ SkDebugf("frac_y = %f\n", SkFixedToFloat(y));
+ }
+ #endif
+
+ // If we're using mask blitter, we advance the mask row in this function
+ // to save some "if" condition checks.
+ SkAlpha* maskRow = nullptr;
+ if (isUsingMask) {
+ maskRow = static_cast<MaskAdditiveBlitter*>(blitter)->getRow(y >> 16);
+ }
+
+ // Instead of writing one loop that handles both partial-row blit_trapezoid_row
+ // and full-row trapezoid_row together, we use the following 3-stage flow to
+ // handle partial-row blit and full-row blit separately. It will save us much time
+ // on changing y, left, and rite.
+ if (count > 1) {
+ if ((int)(y & 0xFFFF0000) != y) { // There's a partial-row on the top
+ count--;
+ SkFixed nextY = SkFixedCeilToFixed(y + 1);
+ SkFixed dY = nextY - y;
+ SkFixed nextLeft = left + SkFixedMul_lowprec(dLeft, dY);
+ SkFixed nextRite = rite + SkFixedMul_lowprec(dRite, dY);
+ blit_trapezoid_row(blitter, y >> 16, left & kSnapMask, rite & kSnapMask,
+ nextLeft & kSnapMask, nextRite & kSnapMask, leftE->fDY, riteE->fDY,
+ getPartialAlpha(0xFF, dY), maskRow, isUsingMask);
+ left = nextLeft; rite = nextRite; y = nextY;
+ }
+
+ while (count > 1) { // Full rows in the middle
+ count--;
+ if (isUsingMask) {
+ maskRow = static_cast<MaskAdditiveBlitter*>(blitter)->getRow(y >> 16);
+ }
+ SkFixed nextY = y + SK_Fixed1, nextLeft = left + dLeft, nextRite = rite + dRite;
+ blit_trapezoid_row(blitter, y >> 16, left & kSnapMask, rite & kSnapMask,
+ nextLeft & kSnapMask, nextRite & kSnapMask,
+ leftE->fDY, riteE->fDY, 0xFF, maskRow, isUsingMask);
+ left = nextLeft; rite = nextRite; y = nextY;
+ }
+ }
+
+ if (isUsingMask) {
+ maskRow = static_cast<MaskAdditiveBlitter*>(blitter)->getRow(y >> 16);
+ }
+
+ SkFixed dY = local_bot_fixed - y; // partial-row on the bottom
+ SkASSERT(dY <= SK_Fixed1);
+ // Smooth jumping to integer y may make the last nextLeft/nextRite out of bound.
+ // Take them back into the bound here.
+ SkFixed nextLeft = SkTMax(left + SkFixedMul_lowprec(dLeft, dY), leftBound);
+ SkFixed nextRite = SkTMin(rite + SkFixedMul_lowprec(dRite, dY), riteBound);
+ blit_trapezoid_row(blitter, y >> 16, left & kSnapMask, rite & kSnapMask,
+ nextLeft & kSnapMask, nextRite & kSnapMask, leftE->fDY, riteE->fDY,
+ getPartialAlpha(0xFF, dY), maskRow, isUsingMask);
+ left = nextLeft; rite = nextRite; y = local_bot_fixed;
+ left -= kSnapHalf; rite -= kSnapHalf;
+ }
+
+ leftE->fX = left;
+ riteE->fX = rite;
+ leftE->fY = riteE->fY = y;
+ }
+
+END_WALK:
+ ;
+ #ifdef SK_DEBUG
+ SkDebugf("frac_y_cnt = %d, total_y_cnt = %d\n", frac_y_cnt, total_y_cnt);
+ #endif
+}
+
+void SkScan::aaa_fill_path(const SkPath& path, const SkIRect* clipRect, AdditiveBlitter* blitter,
+ int start_y, int stop_y, const SkRegion& clipRgn, bool isUsingMask) {
+ SkASSERT(blitter);
+
+ if (path.isInverseFillType() || !path.isConvex()) {
+ // fall back to supersampling AA
+ SkScan::AntiFillPath(path, clipRgn, blitter->getRealBlitter(true), false);
+ return;
+ }
+
+ SkEdgeBuilder builder;
+
+ // If we're convex, then we need both edges, even the right edge is past the clip
+ const bool canCullToTheRight = !path.isConvex();
+
+ SkASSERT(GlobalAAConfig::getInstance().fUseAnalyticAA);
+ int count = builder.build(path, clipRect, 0, canCullToTheRight, true);
+ SkASSERT(count >= 0);
+
+ SkAnalyticEdge** list = (SkAnalyticEdge**)builder.analyticEdgeList();
+
+ SkIRect rect = clipRgn.getBounds();
+ if (0 == count) {
+ if (path.isInverseFillType()) {
+ /*
+ * Since we are in inverse-fill, our caller has already drawn above
+ * our top (start_y) and will draw below our bottom (stop_y). Thus
+ * we need to restrict our drawing to the intersection of the clip
+ * and those two limits.
+ */
+ if (rect.fTop < start_y) {
+ rect.fTop = start_y;
+ }
+ if (rect.fBottom > stop_y) {
+ rect.fBottom = stop_y;
+ }
+ if (!rect.isEmpty()) {
+ blitter->blitRect(rect.fLeft, rect.fTop, rect.width(), rect.height());
+ }
+ }
+ return;
+ }
+
+ SkAnalyticEdge headEdge, tailEdge, *last;
+ // this returns the first and last edge after they're sorted into a dlink list
+ SkAnalyticEdge* edge = sort_edges(list, count, &last);
+
+ headEdge.fPrev = nullptr;
+ headEdge.fNext = edge;
+ headEdge.fUpperY = headEdge.fLowerY = SK_MinS32;
+ headEdge.fX = SK_MinS32;
+ headEdge.fDX = 0;
+ headEdge.fDY = SK_MaxS32;
+ headEdge.fUpperX = SK_MinS32;
+ edge->fPrev = &headEdge;
+
+ tailEdge.fPrev = last;
+ tailEdge.fNext = nullptr;
+ tailEdge.fUpperY = tailEdge.fLowerY = SK_MaxS32;
+ headEdge.fX = SK_MaxS32;
+ headEdge.fDX = 0;
+ headEdge.fDY = SK_MaxS32;
+ headEdge.fUpperX = SK_MaxS32;
+ last->fNext = &tailEdge;
+
+ // now edge is the head of the sorted linklist
+
+ if (clipRect && start_y < clipRect->fTop) {
+ start_y = clipRect->fTop;
+ }
+ if (clipRect && stop_y > clipRect->fBottom) {
+ stop_y = clipRect->fBottom;
+ }
+
+ if (!path.isInverseFillType() && path.isConvex()) {
+ SkASSERT(count >= 2); // convex walker does not handle missing right edges
+ aaa_walk_convex_edges(&headEdge, blitter, start_y, stop_y,
+ rect.fLeft << 16, rect.fRight << 16, isUsingMask);
+ } else {
+ SkFAIL("Concave AAA is not yet implemented!");
+ }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+void SkScan::AAAFillPath(const SkPath& path, const SkRegion& origClip, SkBlitter* blitter) {
+ if (origClip.isEmpty()) {
+ return;
+ }
+
+ const bool isInverse = path.isInverseFillType();
+ SkIRect ir;
+ path.getBounds().roundOut(&ir);
+ if (ir.isEmpty()) {
+ if (isInverse) {
+ blitter->blitRegion(origClip);
+ }
+ return;
+ }
+
+ SkIRect clippedIR;
+ if (isInverse) {
+ // If the path is an inverse fill, it's going to fill the entire
+ // clip, and we care whether the entire clip exceeds our limits.
+ clippedIR = origClip.getBounds();
+ } else {
+ if (!clippedIR.intersect(ir, origClip.getBounds())) {
+ return;
+ }
+ }
+
+ // Our antialiasing can't handle a clip larger than 32767, so we restrict
+ // the clip to that limit here. (the runs[] uses int16_t for its index).
+ //
+ // A more general solution (one that could also eliminate the need to
+ // disable aa based on ir bounds (see overflows_short_shift) would be
+ // to tile the clip/target...
+ SkRegion tmpClipStorage;
+ const SkRegion* clipRgn = &origClip;
+ {
+ static const int32_t kMaxClipCoord = 32767;
+ const SkIRect& bounds = origClip.getBounds();
+ if (bounds.fRight > kMaxClipCoord || bounds.fBottom > kMaxClipCoord) {
+ SkIRect limit = { 0, 0, kMaxClipCoord, kMaxClipCoord };
+ tmpClipStorage.op(origClip, limit, SkRegion::kIntersect_Op);
+ clipRgn = &tmpClipStorage;
+ }
+ }
+ // for here down, use clipRgn, not origClip
+
+ SkScanClipper clipper(blitter, clipRgn, ir);
+ const SkIRect* clipRect = clipper.getClipRect();
+
+ if (clipper.getBlitter() == nullptr) { // clipped out
+ if (isInverse) {
+ blitter->blitRegion(*clipRgn);
+ }
+ return;
+ }
+
+ // now use the (possibly wrapped) blitter
+ blitter = clipper.getBlitter();
+
+ if (isInverse) {
+ // Currently, we use the old path to render the inverse path,
+ // so we don't need this.
+ // sk_blit_above(blitter, ir, *clipRgn);
+ }
+
+ SkASSERT(SkIntToScalar(ir.fTop) <= path.getBounds().fTop);
+
+ if (MaskAdditiveBlitter::canHandleRect(ir) && !isInverse) {
+ MaskAdditiveBlitter additiveBlitter(blitter, ir, *clipRgn, isInverse);
+ aaa_fill_path(path, clipRect, &additiveBlitter, ir.fTop, ir.fBottom, *clipRgn, true);
+ } else {
+ RunBasedAdditiveBlitter additiveBlitter(blitter, ir, *clipRgn, isInverse);
+ aaa_fill_path(path, clipRect, &additiveBlitter, ir.fTop, ir.fBottom, *clipRgn, false);
+ }
+
+ if (isInverse) {
+ // Currently, we use the old path to render the inverse path,
+ // so we don't need this.
+ // sk_blit_below(blitter, ir, *clipRgn);
+ }
+}
+
+// This almost copies SkScan::AntiFillPath
+void SkScan::AAAFillPath(const SkPath& path, const SkRasterClip& clip, SkBlitter* blitter) {
+ if (clip.isEmpty()) {
+ return;
+ }
+
+ if (clip.isBW()) {
+ AAAFillPath(path, clip.bwRgn(), blitter);
+ } else {
+ SkRegion tmp;
+ SkAAClipBlitter aaBlitter;
+
+ tmp.setRect(clip.getBounds());
+ aaBlitter.init(blitter, &clip.aaRgn());
+ AAAFillPath(path, tmp, &aaBlitter);
+ }
+}
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