diff options
Diffstat (limited to 'src/core')
| -rw-r--r-- | src/core/Sk4px.h | 8 | ||||
| -rw-r--r-- | src/core/SkXfermode.cpp | 31 |
2 files changed, 31 insertions, 8 deletions
diff --git a/src/core/Sk4px.h b/src/core/Sk4px.h index 5537b90230..028630d100 100644 --- a/src/core/Sk4px.h +++ b/src/core/Sk4px.h @@ -20,6 +20,10 @@ public: Sk4px alphas() const; // ARGB argb XYZW xyzw -> AAAA aaaa XXXX xxxx + // Mask away color or alpha lanes. + Sk4px zeroColors() const; // ARGB argb XYZW xyzw -> A000 a000 X000 x000 + Sk4px zeroAlphas() const; // ARGB argb XYZW xyzw -> 0RGB 0rgb 0YZW 0yzw + Sk4px inv() const { return Sk16b(255) - *this; } // When loading or storing fewer than 4 SkPMColors, we use the low lanes. @@ -56,6 +60,10 @@ public: Wide widenLo() const; // ARGB -> 0A 0R 0G 0B Wide widenHi() const; // ARGB -> A0 R0 G0 B0 Wide mulWiden(const Sk16b&) const; // 8-bit x 8-bit -> 16-bit components. + Wide mul255Widen() const { + // TODO: x*255 = x*256-x, so something like this->widenHi() - this->widenLo()? + return this->mulWiden(Sk16b(255)); + } // A generic driver that maps fn over a src array into a dst array. // fn should take an Sk4px (4 src pixels) and return an Sk4px (4 dst pixels). diff --git a/src/core/SkXfermode.cpp b/src/core/SkXfermode.cpp index 2abe55a8ca..8824a8875f 100644 --- a/src/core/SkXfermode.cpp +++ b/src/core/SkXfermode.cpp @@ -1333,6 +1333,7 @@ struct Multiply4f { static const SkXfermode::Mode kMode = SkXfermode::kMultiply_Mode; }; +// [ sa + da - sa*da, sc + dc - 2*min(sc*da, dc*sa) ] (And notice sa*da == min(sa*da, da*sa).) struct Difference4f { static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) { const Sk4f inv255(gInv255); @@ -1344,10 +1345,17 @@ struct Difference4f { Sk4f ra = sc + dc - min; return check_as_pmfloat(ra - min * SkPMFloat(0, 1, 1, 1)); } + static Sk4px Xfer(const Sk4px& src, const Sk4px& dst) { + auto m = Sk4px::Wide(Sk16h::Min(src.mulWiden(dst.alphas()), dst.mulWiden(src.alphas()))) + .div255RoundNarrow(); + // There's no chance of underflow, and if we subtract m before adding src+dst, no overflow. + return (src - m) + (dst - m.zeroAlphas()); + } static const bool kFoldCoverageIntoSrcAlpha = false; static const SkXfermode::Mode kMode = SkXfermode::kDifference_Mode; }; +// [ sa + da - sa*da, sc + dc - 2*sc*dc ] struct Exclusion4f { static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) { const Sk4f inv255(gInv255); @@ -1357,6 +1365,11 @@ struct Exclusion4f { Sk4f ra = sc + dc - prod; return check_as_pmfloat(ra - prod * SkPMFloat(0, 1, 1, 1)); } + static Sk4px Xfer(const Sk4px& src, const Sk4px& dst) { + auto p = src.mulWiden(dst).div255RoundNarrow(); + // There's no chance of underflow, and if we subtract p before adding src+dst, no overflow. + return (src - p) + (dst - p.zeroAlphas()); + } static const bool kFoldCoverageIntoSrcAlpha = false; static const SkXfermode::Mode kMode = SkXfermode::kExclusion_Mode; }; @@ -1413,7 +1426,7 @@ public: [&](const Sk4px& dst4, const Sk4px& src4, const Sk16b& alpha) { // We can't exploit kFoldCoverageIntoSrcAlpha. That requires >=24-bit intermediates. Sk4px res4 = ProcType::Xfer(src4, dst4); - return Sk4px::Wide(res4.mulWiden(alpha) + dst4.mulWiden(Sk16b(255)-alpha)) + return Sk4px::Wide(res4.mulWiden(alpha) + dst4.mulWiden(Sk4px(alpha).inv())) .div255RoundNarrow(); }); } @@ -1487,13 +1500,15 @@ SkXfermode* create_mode(int iMode) { #if defined(SK_4PX_XFERMODES_ARE_FAST) && !defined(SK_PREFER_LEGACY_FLOAT_XFERMODES) switch (mode) { - case SkXfermode::kSrcATop_Mode: return SkT4pxXfermode<SrcATop4f>::Create(rec); - case SkXfermode::kDstATop_Mode: return SkT4pxXfermode<DstATop4f>::Create(rec); - case SkXfermode::kXor_Mode: return SkT4pxXfermode<Xor4f>::Create(rec); - case SkXfermode::kPlus_Mode: return SkT4pxXfermode<Plus4f>::Create(rec); - case SkXfermode::kModulate_Mode: return SkT4pxXfermode<Modulate4f>::Create(rec); - case SkXfermode::kScreen_Mode: return SkT4pxXfermode<Screen4f>::Create(rec); - case SkXfermode::kMultiply_Mode: return SkT4pxXfermode<Multiply4f>::Create(rec); + case SkXfermode::kSrcATop_Mode: return SkT4pxXfermode<SrcATop4f>::Create(rec); + case SkXfermode::kDstATop_Mode: return SkT4pxXfermode<DstATop4f>::Create(rec); + case SkXfermode::kXor_Mode: return SkT4pxXfermode<Xor4f>::Create(rec); + case SkXfermode::kPlus_Mode: return SkT4pxXfermode<Plus4f>::Create(rec); + case SkXfermode::kModulate_Mode: return SkT4pxXfermode<Modulate4f>::Create(rec); + case SkXfermode::kScreen_Mode: return SkT4pxXfermode<Screen4f>::Create(rec); + case SkXfermode::kMultiply_Mode: return SkT4pxXfermode<Multiply4f>::Create(rec); + case SkXfermode::kDifference_Mode: return SkT4pxXfermode<Difference4f>::Create(rec); + case SkXfermode::kExclusion_Mode: return SkT4pxXfermode<Exclusion4f>::Create(rec); default: break; } #endif |