From f941ea32e44a2436d235e83ef1a434289a9d9c1e Mon Sep 17 00:00:00 2001 From: George Wright Date: Wed, 23 May 2012 11:40:25 -0400 Subject: [PATCH 08/10] Bug 755869 - [11] Re-apply bug 687188 - Skia radial gradients should use the 0/1 color stop values for clamping. r=mattwoodrow --- gfx/skia/src/effects/SkGradientShader.cpp | 76 +++++++++++++++++++++++------ 1 files changed, 61 insertions(+), 15 deletions(-) diff --git a/gfx/skia/src/effects/SkGradientShader.cpp b/gfx/skia/src/effects/SkGradientShader.cpp index 59ba48c..ea05a39 100644 --- a/gfx/skia/src/effects/SkGradientShader.cpp +++ b/gfx/skia/src/effects/SkGradientShader.cpp @@ -204,6 +204,7 @@ private: mutable SkMallocPixelRef* fCache32PixelRef; mutable unsigned fCacheAlpha; // the alpha value we used when we computed the cache. larger than 8bits so we can store uninitialized value + static SkPMColor PremultiplyColor(SkColor c0, U8CPU alpha); static void Build16bitCache(uint16_t[], SkColor c0, SkColor c1, int count); static void Build32bitCache(SkPMColor[], SkColor c0, SkColor c1, int count, U8CPU alpha); @@ -507,6 +508,21 @@ static inline U8CPU dither_ceil_fixed_to_8(SkFixed n) { return ((n << 1) - (n | (n >> 8))) >> 8; } +SkPMColor Gradient_Shader::PremultiplyColor(SkColor c0, U8CPU paintAlpha) +{ + SkFixed a = SkMulDiv255Round(SkColorGetA(c0), paintAlpha); + SkFixed r = SkColorGetR(c0); + SkFixed g = SkColorGetG(c0); + SkFixed b = SkColorGetB(c0); + + a = SkIntToFixed(a) + 0x8000; + r = SkIntToFixed(r) + 0x8000; + g = SkIntToFixed(g) + 0x8000; + b = SkIntToFixed(b) + 0x8000; + + return SkPremultiplyARGBInline(a >> 16, r >> 16, g >> 16, b >> 16); +} + void Gradient_Shader::Build32bitCache(SkPMColor cache[], SkColor c0, SkColor c1, int count, U8CPU paintAlpha) { SkASSERT(count > 1); @@ -628,14 +644,14 @@ static void complete_32bit_cache(SkPMColor* cache, int stride) { const SkPMColor* Gradient_Shader::getCache32() const { if (fCache32 == NULL) { // double the count for dither entries - const int entryCount = kCache32Count * 2; + const int entryCount = kCache32Count * 2 + 2; const size_t allocSize = sizeof(SkPMColor) * entryCount; if (NULL == fCache32PixelRef) { fCache32PixelRef = SkNEW_ARGS(SkMallocPixelRef, (NULL, allocSize, NULL)); } - fCache32 = (SkPMColor*)fCache32PixelRef->getAddr(); + fCache32 = (SkPMColor*)fCache32PixelRef->getAddr() + 1; if (fColorCount == 2) { Build32bitCache(fCache32, fOrigColors[0], fOrigColors[1], kGradient32Length, fCacheAlpha); @@ -659,7 +675,7 @@ const SkPMColor* Gradient_Shader::getCache32() const { SkMallocPixelRef* newPR = SkNEW_ARGS(SkMallocPixelRef, (NULL, allocSize, NULL)); SkPMColor* linear = fCache32; // just computed linear data - SkPMColor* mapped = (SkPMColor*)newPR->getAddr(); // storage for mapped data + SkPMColor* mapped = (SkPMColor*)newPR->getAddr() + 1; // storage for mapped data SkUnitMapper* map = fMapper; for (int i = 0; i < kGradient32Length; i++) { int index = map->mapUnit16((i << 8) | i) >> 8; @@ -668,10 +684,13 @@ const SkPMColor* Gradient_Shader::getCache32() const { } fCache32PixelRef->unref(); fCache32PixelRef = newPR; - fCache32 = (SkPMColor*)newPR->getAddr(); + fCache32 = (SkPMColor*)newPR->getAddr() + 1; } complete_32bit_cache(fCache32, kCache32Count); } + //Write the clamp colours into the first and last entries of fCache32 + fCache32[-1] = PremultiplyColor(fOrigColors[0], fCacheAlpha); + fCache32[kCache32Count * 2] = PremultiplyColor(fOrigColors[fColorCount - 1], fCacheAlpha); return fCache32; } @@ -857,6 +876,18 @@ void shadeSpan_linear_vertical(TileProc proc, SkFixed dx, SkFixed fx, SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, int toggle, int count) { + if (proc == clamp_tileproc) { + // Read out clamp values from beginning/end of the cache. No need to lerp + // or dither + if (fx < 0) { + sk_memset32(dstC, cache[-1], count); + return; + } else if (fx > 0xFFFF) { + sk_memset32(dstC, cache[Gradient_Shader::kCache32Count * 2], count); + return; + } + } + // We're a vertical gradient, so no change in a span. // If colors change sharply across the gradient, dithering is // insufficient (it subsamples the color space) and we need to lerp. @@ -875,6 +906,18 @@ void shadeSpan_linear_vertical_lerp(TileProc proc, SkFixed dx, SkFixed fx, SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, int toggle, int count) { + if (proc == clamp_tileproc) { + // Read out clamp values from beginning/end of the cache. No need to lerp + // or dither + if (fx < 0) { + sk_memset32(dstC, cache[-1], count); + return; + } else if (fx > 0xFFFF) { + sk_memset32(dstC, cache[Gradient_Shader::kCache32Count * 2], count); + return; + } + } + // We're a vertical gradient, so no change in a span. // If colors change sharply across the gradient, dithering is // insufficient (it subsamples the color space) and we need to lerp. @@ -900,10 +943,8 @@ void shadeSpan_linear_clamp(TileProc proc, SkFixed dx, SkFixed fx, range.init(fx, dx, count, 0, Gradient_Shader::kGradient32Length); if ((count = range.fCount0) > 0) { - sk_memset32_dither(dstC, - cache[toggle + range.fV0], - cache[(toggle ^ Gradient_Shader::kDitherStride32) + range.fV0], - count); + // Shouldn't be any need to dither for clamping? + sk_memset32(dstC, cache[-1], count); dstC += count; } if ((count = range.fCount1) > 0) { @@ -922,10 +963,8 @@ void shadeSpan_linear_clamp(TileProc proc, SkFixed dx, SkFixed fx, } } if ((count = range.fCount2) > 0) { - sk_memset32_dither(dstC, - cache[toggle + range.fV1], - cache[(toggle ^ Gradient_Shader::kDitherStride32) + range.fV1], - count); + // Shouldn't be any need to dither for clamping? + sk_memset32(dstC, cache[Gradient_Shader::kCache32Count * 2], count); } } @@ -1796,9 +1835,16 @@ void shadeSpan_twopoint_clamp(SkScalar fx, SkScalar dx, for (; count > 0; --count) { SkFixed t = two_point_radial(b, fx, fy, fSr2D2, foura, fOneOverTwoA, posRoot); - SkFixed index = SkClampMax(t, 0xFFFF); - SkASSERT(index <= 0xFFFF); - *dstC++ = cache[index >> Gradient_Shader::kCache32Shift]; + + if (t < 0) { + *dstC++ = cache[-1]; + } else if (t > 0xFFFF) { + *dstC++ = cache[Gradient_Shader::kCache32Count * 2]; + } else { + SkASSERT(t <= 0xFFFF); + *dstC++ = cache[t >> Gradient_Shader::kCache32Shift]; + } + fx += dx; fy += dy; b += db; -- 1.7.5.4