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-rw-r--r--skia/sgl/SkEdge.cpp85
1 files changed, 62 insertions, 23 deletions
diff --git a/skia/sgl/SkEdge.cpp b/skia/sgl/SkEdge.cpp
index 3a9474c..b079bef 100644
--- a/skia/sgl/SkEdge.cpp
+++ b/skia/sgl/SkEdge.cpp
@@ -1,6 +1,6 @@
/* libs/graphics/sgl/SkEdge.cpp
**
-** Copyright 2006, Google Inc.
+** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
@@ -77,7 +77,12 @@ int SkEdge::setLine(const SkPoint& p0, const SkPoint& p1, const SkIRect* clip,
fX = SkFDot6ToFixed(x0 + SkFixedMul(slope, (32 - y0) & 63)); // + SK_Fixed1/2
fDX = slope;
- fFirstY = (int16_t)(top); // inlined skToS16()
+#if 0
+ // CHANGED FOR CHROME
+ fFirstY = top;
+ fLastY = bot - 1;
+#else
+ fFirstY = top;
if (top != (long)fFirstY) {
if (fFirstY < top) {
fFirstY = std::numeric_limits<int16_t>::max();
@@ -86,7 +91,7 @@ int SkEdge::setLine(const SkPoint& p0, const SkPoint& p1, const SkIRect* clip,
}
fX -= fDX * (top - (long)fFirstY);
}
- fLastY = (int16_t)(bot - 1); // inlined SkToS16()
+ fLastY = bot - 1;
if (bot-1 != (long)fLastY) {
if (fLastY < bot-1) {
fLastY = std::numeric_limits<int16_t>::max();
@@ -94,6 +99,7 @@ int SkEdge::setLine(const SkPoint& p0, const SkPoint& p1, const SkIRect* clip,
fLastY = std::numeric_limits<int16_t>::min();
}
}
+#endif
fCurveCount = 0;
fWinding = SkToS8(winding);
fCurveShift = 0;
@@ -109,7 +115,7 @@ int SkEdge::updateLine(SkFixed x0, SkFixed y0, SkFixed x1, SkFixed y1)
{
SkASSERT(fWinding == 1 || fWinding == -1);
SkASSERT(fCurveCount != 0);
- SkASSERT(fCurveShift != 0);
+// SkASSERT(fCurveShift != 0);
y0 >>= 10;
y1 >>= 10;
@@ -132,8 +138,8 @@ int SkEdge::updateLine(SkFixed x0, SkFixed y0, SkFixed x1, SkFixed y1)
fX = SkFDot6ToFixed(x0 + SkFixedMul(slope, (32 - y0) & 63)); // + SK_Fixed1/2
fDX = slope;
- fFirstY = SkToS16(top);
- fLastY = SkToS16(bot - 1);
+ fFirstY = top;
+ fLastY = bot - 1;
return 1;
}
@@ -153,7 +159,14 @@ void SkEdge::chopLineWithClip(const SkIRect& clip)
}
}
-/////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+/* We store 1<<shift in a (signed) byte, so its maximum value is 1<<6 == 64.
+ Note that this limits the number of lines we use to approximate a curve.
+ If we need to increase this, we need to store fCurveCount in something
+ larger than int8_t.
+*/
+#define MAX_COEFF_SHIFT 6
static inline SkFDot6 cheap_distance(SkFDot6 dx, SkFDot6 dy)
{
@@ -176,7 +189,7 @@ static inline int diff_to_shift(SkFDot6 dx, SkFDot6 dy)
// down by 5 should give us 1/2 pixel accuracy (assuming our dist is accurate...)
// this is chosen by heuristic: make it as big as possible (to minimize segments)
// ... but small enough so that our curves still look smooth
- dist >>= 5;
+ dist = (dist + (1 << 4)) >> 5;
// each subdivision (shift value) cuts this dist (error) by 1/4
return (32 - SkCLZ(dist)) >> 1;
@@ -230,14 +243,19 @@ int SkQuadraticEdge::setQuadratic(const SkPoint pts[3], const SkIRect* clip, int
SkFDot6 dx = ((x1 << 1) - x0 - x2) >> 2;
SkFDot6 dy = ((y1 << 1) - y0 - y2) >> 2;
shift = diff_to_shift(dx, dy);
+ SkASSERT(shift >= 0);
}
// need at least 1 subdivision for our bias trick
- if (shift == 0)
+ if (shift == 0) {
shift = 1;
-
+ } else if (shift > MAX_COEFF_SHIFT) {
+ shift = MAX_COEFF_SHIFT;
+ }
+
fWinding = SkToS8(winding);
fCurveShift = SkToU8(shift);
- fCurveCount = SkToS16(1 << shift);
+ //fCubicDShift only set for cubics
+ fCurveCount = SkToS8(1 << shift);
SkFixed A = SkFDot6ToFixed(x0 - x1 - x1 + x2);
SkFixed B = SkFDot6ToFixed(x1 - x0 + x1 - x0);
@@ -309,6 +327,11 @@ int SkQuadraticEdge::updateQuadratic()
/////////////////////////////////////////////////////////////////////////
+static inline int SkFDot6UpShift(SkFDot6 x, int upShift) {
+ SkASSERT((x << upShift >> upShift) == x);
+ return x << upShift;
+}
+
/* f(1/3) = (8a + 12b + 6c + d) / 27
f(2/3) = (a + 6b + 12c + 8d) / 27
@@ -386,23 +409,38 @@ int SkCubicEdge::setCubic(const SkPoint pts[4], const SkIRect* clip, int shift)
}
// need at least 1 subdivision for our bias trick
SkASSERT(shift > 0);
+ if (shift > MAX_COEFF_SHIFT) {
+ shift = MAX_COEFF_SHIFT;
+ }
+
+ /* Since our in coming data is initially shifted down by 10 (or 8 in
+ antialias). That means the most we can shift up is 8. However, we
+ compute coefficients with a 3*, so the safest upshift is really 6
+ */
+ int upShift = 6; // largest safe value
+ int downShift = shift + upShift - 10;
+ if (downShift < 0) {
+ downShift = 0;
+ upShift = 10 - shift;
+ }
fWinding = SkToS8(winding);
+ fCurveCount = SkToS8(-1 << shift);
fCurveShift = SkToU8(shift);
- fCurveCount = SkToS16(-1 << shift);
+ fCubicDShift = SkToU8(downShift);
- SkFixed B = SkFDot6ToFixed(3 * (x1 - x0));
- SkFixed C = SkFDot6ToFixed(3 * (x0 - x1 - x1 + x2));
- SkFixed D = SkFDot6ToFixed(x3 + 3 * (x1 - x2) - x0);
+ SkFixed B = SkFDot6UpShift(3 * (x1 - x0), upShift);
+ SkFixed C = SkFDot6UpShift(3 * (x0 - x1 - x1 + x2), upShift);
+ SkFixed D = SkFDot6UpShift(x3 + 3 * (x1 - x2) - x0, upShift);
fCx = SkFDot6ToFixed(x0);
fCDx = B + (C >> shift) + (D >> 2*shift); // biased by shift
fCDDx = 2*C + (3*D >> (shift - 1)); // biased by 2*shift
fCDDDx = 3*D >> (shift - 1); // biased by 2*shift
- B = SkFDot6ToFixed(3 * (y1 - y0));
- C = SkFDot6ToFixed(3 * (y0 - y1 - y1 + y2));
- D = SkFDot6ToFixed(y3 + 3 * (y1 - y2) - y0);
+ B = SkFDot6UpShift(3 * (y1 - y0), upShift);
+ C = SkFDot6UpShift(3 * (y0 - y1 - y1 + y2), upShift);
+ D = SkFDot6UpShift(y3 + 3 * (y1 - y2) - y0, upShift);
fCy = SkFDot6ToFixed(y0);
fCDy = B + (C >> shift) + (D >> 2*shift); // biased by shift
@@ -431,19 +469,20 @@ int SkCubicEdge::updateCubic()
SkFixed oldx = fCx;
SkFixed oldy = fCy;
SkFixed newx, newy;
- int shift = fCurveShift;
+ const int ddshift = fCurveShift;
+ const int dshift = fCubicDShift;
SkASSERT(count < 0);
do {
if (++count < 0)
{
- newx = oldx + (fCDx >> shift);
- fCDx += fCDDx >> shift;
+ newx = oldx + (fCDx >> dshift);
+ fCDx += fCDDx >> ddshift;
fCDDx += fCDDDx;
- newy = oldy + (fCDy >> shift);
- fCDy += fCDDy >> shift;
+ newy = oldy + (fCDy >> dshift);
+ fCDy += fCDDy >> ddshift;
fCDDy += fCDDDy;
}
else // last segment
generated by cgit v1.1 at 2025-02-04 23:41:31 +0000