The Tor Browser: gfx/skia/trunk/src/core/SkXfermode.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/core/SkXfermode.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/core/SkXfermode.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /*
  * Copyright 2006 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 "SkXfermode.h"
 #include "SkXfermode_proccoeff.h"
 #include "SkColorPriv.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMathPriv.h"
 #include "SkString.h"
 #include "SkUtilsArm.h"
 #if !SK_ARM_NEON_IS_NONE
 #include "SkXfermode_opts_arm_neon.h"
 #endif
 #define SkAlphaMulAlpha(a, b)   SkMulDiv255Round(a, b)
 #if 0
 // idea for higher precision blends in xfer procs (and slightly faster)
 // see DstATop as a probable caller
 static U8CPU mulmuldiv255round(U8CPU a, U8CPU b, U8CPU c, U8CPU d) {
     SkASSERT(a <= 255);
     SkASSERT(b <= 255);
     SkASSERT(c <= 255);
     SkASSERT(d <= 255);
     unsigned prod = SkMulS16(a, b) + SkMulS16(c, d) + 128;
     unsigned result = (prod + (prod >> 8)) >> 8;
     SkASSERT(result <= 255);
     return result;
 }
 #endif
 static inline unsigned saturated_add(unsigned a, unsigned b) {
     SkASSERT(a <= 255);
     SkASSERT(b <= 255);
     unsigned sum = a + b;
     if (sum > 255) {
         sum = 255;
     }
     return sum;
 }
 static inline int clamp_signed_byte(int n) {
     if (n < 0) {
         n = 0;
     } else if (n > 255) {
         n = 255;
     }
     return n;
 }
 static inline int clamp_div255round(int prod) {
     if (prod <= 0) {
         return 0;
     } else if (prod >= 255*255) {
         return 255;
     } else {
         return SkDiv255Round(prod);
     }
 }
 ///////////////////////////////////////////////////////////////////////////////
 //  kClear_Mode,    //!< [0, 0]
 static SkPMColor clear_modeproc(SkPMColor src, SkPMColor dst) {
     return 0;
 }
 //  kSrc_Mode,      //!< [Sa, Sc]
 static SkPMColor src_modeproc(SkPMColor src, SkPMColor dst) {
     return src;
 }
 //  kDst_Mode,      //!< [Da, Dc]
 static SkPMColor dst_modeproc(SkPMColor src, SkPMColor dst) {
     return dst;
 }
 //  kSrcOver_Mode,  //!< [Sa + Da - Sa*Da, Sc + (1 - Sa)*Dc]
 static SkPMColor srcover_modeproc(SkPMColor src, SkPMColor dst) {
 #if 0
     // this is the old, more-correct way, but it doesn't guarantee that dst==255
     // will always stay opaque
     return src + SkAlphaMulQ(dst, SkAlpha255To256(255 - SkGetPackedA32(src)));
 #else
     // this is slightly faster, but more importantly guarantees that dst==255
     // will always stay opaque
     return src + SkAlphaMulQ(dst, 256 - SkGetPackedA32(src));
 #endif
 }
 //  kDstOver_Mode,  //!< [Sa + Da - Sa*Da, Dc + (1 - Da)*Sc]
 static SkPMColor dstover_modeproc(SkPMColor src, SkPMColor dst) {
     // this is the reverse of srcover, just flipping src and dst
     // see srcover's comment about the 256 for opaqueness guarantees
     return dst + SkAlphaMulQ(src, 256 - SkGetPackedA32(dst));
 }
 //  kSrcIn_Mode,    //!< [Sa * Da, Sc * Da]
 static SkPMColor srcin_modeproc(SkPMColor src, SkPMColor dst) {
     return SkAlphaMulQ(src, SkAlpha255To256(SkGetPackedA32(dst)));
 }
 //  kDstIn_Mode,    //!< [Sa * Da, Sa * Dc]
 static SkPMColor dstin_modeproc(SkPMColor src, SkPMColor dst) {
     return SkAlphaMulQ(dst, SkAlpha255To256(SkGetPackedA32(src)));
 }
 //  kSrcOut_Mode,   //!< [Sa * (1 - Da), Sc * (1 - Da)]
 static SkPMColor srcout_modeproc(SkPMColor src, SkPMColor dst) {
     return SkAlphaMulQ(src, SkAlpha255To256(255 - SkGetPackedA32(dst)));
 }
 //  kDstOut_Mode,   //!< [Da * (1 - Sa), Dc * (1 - Sa)]
 static SkPMColor dstout_modeproc(SkPMColor src, SkPMColor dst) {
     return SkAlphaMulQ(dst, SkAlpha255To256(255 - SkGetPackedA32(src)));
 }
 //  kSrcATop_Mode,  //!< [Da, Sc * Da + (1 - Sa) * Dc]
 static SkPMColor srcatop_modeproc(SkPMColor src, SkPMColor dst) {
     unsigned sa = SkGetPackedA32(src);
     unsigned da = SkGetPackedA32(dst);
     unsigned isa = 255 - sa;
     return SkPackARGB32(da,
                         SkAlphaMulAlpha(da, SkGetPackedR32(src)) +
                             SkAlphaMulAlpha(isa, SkGetPackedR32(dst)),
                         SkAlphaMulAlpha(da, SkGetPackedG32(src)) +
                             SkAlphaMulAlpha(isa, SkGetPackedG32(dst)),
                         SkAlphaMulAlpha(da, SkGetPackedB32(src)) +
                             SkAlphaMulAlpha(isa, SkGetPackedB32(dst)));
 }
 //  kDstATop_Mode,  //!< [Sa, Sa * Dc + Sc * (1 - Da)]
 static SkPMColor dstatop_modeproc(SkPMColor src, SkPMColor dst) {
     unsigned sa = SkGetPackedA32(src);
     unsigned da = SkGetPackedA32(dst);
     unsigned ida = 255 - da;
     return SkPackARGB32(sa,
                         SkAlphaMulAlpha(ida, SkGetPackedR32(src)) +
                             SkAlphaMulAlpha(sa, SkGetPackedR32(dst)),
                         SkAlphaMulAlpha(ida, SkGetPackedG32(src)) +
                             SkAlphaMulAlpha(sa, SkGetPackedG32(dst)),
                         SkAlphaMulAlpha(ida, SkGetPackedB32(src)) +
                             SkAlphaMulAlpha(sa, SkGetPackedB32(dst)));
 }
 //  kXor_Mode   [Sa + Da - 2 * Sa * Da, Sc * (1 - Da) + (1 - Sa) * Dc]
 static SkPMColor xor_modeproc(SkPMColor src, SkPMColor dst) {
     unsigned sa = SkGetPackedA32(src);
     unsigned da = SkGetPackedA32(dst);
     unsigned isa = 255 - sa;
     unsigned ida = 255 - da;
     return SkPackARGB32(sa + da - (SkAlphaMulAlpha(sa, da) << 1),
                         SkAlphaMulAlpha(ida, SkGetPackedR32(src)) +
                             SkAlphaMulAlpha(isa, SkGetPackedR32(dst)),
                         SkAlphaMulAlpha(ida, SkGetPackedG32(src)) +
                             SkAlphaMulAlpha(isa, SkGetPackedG32(dst)),
                         SkAlphaMulAlpha(ida, SkGetPackedB32(src)) +
                             SkAlphaMulAlpha(isa, SkGetPackedB32(dst)));
 }
 ///////////////////////////////////////////////////////////////////////////////
 // kPlus_Mode
 static SkPMColor plus_modeproc(SkPMColor src, SkPMColor dst) {
     unsigned b = saturated_add(SkGetPackedB32(src), SkGetPackedB32(dst));
     unsigned g = saturated_add(SkGetPackedG32(src), SkGetPackedG32(dst));
     unsigned r = saturated_add(SkGetPackedR32(src), SkGetPackedR32(dst));
     unsigned a = saturated_add(SkGetPackedA32(src), SkGetPackedA32(dst));
     return SkPackARGB32(a, r, g, b);
 }
 // kModulate_Mode
 static SkPMColor modulate_modeproc(SkPMColor src, SkPMColor dst) {
     int a = SkAlphaMulAlpha(SkGetPackedA32(src), SkGetPackedA32(dst));
     int r = SkAlphaMulAlpha(SkGetPackedR32(src), SkGetPackedR32(dst));
     int g = SkAlphaMulAlpha(SkGetPackedG32(src), SkGetPackedG32(dst));
     int b = SkAlphaMulAlpha(SkGetPackedB32(src), SkGetPackedB32(dst));
     return SkPackARGB32(a, r, g, b);
 }
 static inline int srcover_byte(int a, int b) {
     return a + b - SkAlphaMulAlpha(a, b);
 }
 // kMultiply_Mode
 // B(Cb, Cs) = Cb x Cs
 // multiply uses its own version of blendfunc_byte because sa and da are not needed
 static int blendfunc_multiply_byte(int sc, int dc, int sa, int da) {
     return clamp_div255round(sc * (255 - da)  + dc * (255 - sa)  + sc * dc);
 }
 static SkPMColor multiply_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = blendfunc_multiply_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = blendfunc_multiply_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = blendfunc_multiply_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kScreen_Mode
 static SkPMColor screen_modeproc(SkPMColor src, SkPMColor dst) {
     int a = srcover_byte(SkGetPackedA32(src), SkGetPackedA32(dst));
     int r = srcover_byte(SkGetPackedR32(src), SkGetPackedR32(dst));
     int g = srcover_byte(SkGetPackedG32(src), SkGetPackedG32(dst));
     int b = srcover_byte(SkGetPackedB32(src), SkGetPackedB32(dst));
     return SkPackARGB32(a, r, g, b);
 }
 // kOverlay_Mode
 static inline int overlay_byte(int sc, int dc, int sa, int da) {
     int tmp = sc * (255 - da) + dc * (255 - sa);
     int rc;
     if (2 * dc <= da) {
         rc = 2 * sc * dc;
     } else {
         rc = sa * da - 2 * (da - dc) * (sa - sc);
     }
     return clamp_div255round(rc + tmp);
 }
 static SkPMColor overlay_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = overlay_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = overlay_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = overlay_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kDarken_Mode
 static inline int darken_byte(int sc, int dc, int sa, int da) {
     int sd = sc * da;
     int ds = dc * sa;
     if (sd < ds) {
         // srcover
         return sc + dc - SkDiv255Round(ds);
     } else {
         // dstover
         return dc + sc - SkDiv255Round(sd);
     }
 }
 static SkPMColor darken_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = darken_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = darken_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = darken_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kLighten_Mode
 static inline int lighten_byte(int sc, int dc, int sa, int da) {
     int sd = sc * da;
     int ds = dc * sa;
     if (sd > ds) {
         // srcover
         return sc + dc - SkDiv255Round(ds);
     } else {
         // dstover
         return dc + sc - SkDiv255Round(sd);
     }
 }
 static SkPMColor lighten_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = lighten_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = lighten_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = lighten_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kColorDodge_Mode
 static inline int colordodge_byte(int sc, int dc, int sa, int da) {
     int diff = sa - sc;
     int rc;
     if (0 == dc) {
         return SkAlphaMulAlpha(sc, 255 - da);
     } else if (0 == diff) {
         rc = sa * da + sc * (255 - da) + dc * (255 - sa);
     } else {
         diff = dc * sa / diff;
         rc = sa * ((da < diff) ? da : diff) + sc * (255 - da) + dc * (255 - sa);
     }
     return clamp_div255round(rc);
 }
 static SkPMColor colordodge_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = colordodge_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = colordodge_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = colordodge_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kColorBurn_Mode
 static inline int colorburn_byte(int sc, int dc, int sa, int da) {
     int rc;
     if (dc == da) {
         rc = sa * da + sc * (255 - da) + dc * (255 - sa);
     } else if (0 == sc) {
         return SkAlphaMulAlpha(dc, 255 - sa);
     } else {
         int tmp = (da - dc) * sa / sc;
         rc = sa * (da - ((da < tmp) ? da : tmp))
             + sc * (255 - da) + dc * (255 - sa);
     }
     return clamp_div255round(rc);
 }
 static SkPMColor colorburn_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = colorburn_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = colorburn_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = colorburn_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kHardLight_Mode
 static inline int hardlight_byte(int sc, int dc, int sa, int da) {
     int rc;
     if (2 * sc <= sa) {
         rc = 2 * sc * dc;
     } else {
         rc = sa * da - 2 * (da - dc) * (sa - sc);
     }
     return clamp_div255round(rc + sc * (255 - da) + dc * (255 - sa));
 }
 static SkPMColor hardlight_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = hardlight_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = hardlight_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = hardlight_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // returns 255 * sqrt(n/255)
 static U8CPU sqrt_unit_byte(U8CPU n) {
     return SkSqrtBits(n, 15+4);
 }
 // kSoftLight_Mode
 static inline int softlight_byte(int sc, int dc, int sa, int da) {
     int m = da ? dc * 256 / da : 0;
     int rc;
     if (2 * sc <= sa) {
         rc = dc * (sa + ((2 * sc - sa) * (256 - m) >> 8));
     } else if (4 * dc <= da) {
         int tmp = (4 * m * (4 * m + 256) * (m - 256) >> 16) + 7 * m;
         rc = dc * sa + (da * (2 * sc - sa) * tmp >> 8);
     } else {
         int tmp = sqrt_unit_byte(m) - m;
         rc = dc * sa + (da * (2 * sc - sa) * tmp >> 8);
     }
     return clamp_div255round(rc + sc * (255 - da) + dc * (255 - sa));
 }
 static SkPMColor softlight_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = softlight_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = softlight_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = softlight_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kDifference_Mode
 static inline int difference_byte(int sc, int dc, int sa, int da) {
     int tmp = SkMin32(sc * da, dc * sa);
     return clamp_signed_byte(sc + dc - 2 * SkDiv255Round(tmp));
 }
 static SkPMColor difference_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = difference_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = difference_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = difference_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // kExclusion_Mode
 static inline int exclusion_byte(int sc, int dc, int, int) {
     // this equations is wacky, wait for SVG to confirm it
     //int r = sc * da + dc * sa - 2 * sc * dc + sc * (255 - da) + dc * (255 - sa);
     // The above equation can be simplified as follows
     int r = 255*(sc + dc) - 2 * sc * dc;
     return clamp_div255round(r);
 }
 static SkPMColor exclusion_modeproc(SkPMColor src, SkPMColor dst) {
     int sa = SkGetPackedA32(src);
     int da = SkGetPackedA32(dst);
     int a = srcover_byte(sa, da);
     int r = exclusion_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da);
     int g = exclusion_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da);
     int b = exclusion_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da);
     return SkPackARGB32(a, r, g, b);
 }
 // The CSS compositing spec introduces the following formulas:
 // (See https://dvcs.w3.org/hg/FXTF/rawfile/tip/compositing/index.html#blendingnonseparable)
 // SkComputeLuminance is similar to this formula but it uses the new definition from Rec. 709
 // while PDF and CG uses the one from Rec. Rec. 601
 // See http://www.glennchan.info/articles/technical/hd-versus-sd-color-space/hd-versus-sd-color-space.htm
 static inline int Lum(int r, int g, int b)
 {
     return SkDiv255Round(r * 77 + g * 150 + b * 28);
 }
 static inline int min2(int a, int b) { return a < b ? a : b; }
 static inline int max2(int a, int b) { return a > b ? a : b; }
 #define minimum(a, b, c) min2(min2(a, b), c)
 #define maximum(a, b, c) max2(max2(a, b), c)
 static inline int Sat(int r, int g, int b) {
     return maximum(r, g, b) - minimum(r, g, b);
 }
 static inline void setSaturationComponents(int* Cmin, int* Cmid, int* Cmax, int s) {
     if(*Cmax > *Cmin) {
         *Cmid =  SkMulDiv(*Cmid - *Cmin, s, *Cmax - *Cmin);
         *Cmax = s;
     } else {
         *Cmax = 0;
         *Cmid = 0;
     }
     *Cmin = 0;
 }
 static inline void SetSat(int* r, int* g, int* b, int s) {
     if(*r <= *g) {
         if(*g <= *b) {
             setSaturationComponents(r, g, b, s);
         } else if(*r <= *b) {
             setSaturationComponents(r, b, g, s);
         } else {
             setSaturationComponents(b, r, g, s);
         }
     } else if(*r <= *b) {
         setSaturationComponents(g, r, b, s);
     } else if(*g <= *b) {
         setSaturationComponents(g, b, r, s);
     } else {
         setSaturationComponents(b, g, r, s);
     }
 }
 static inline void clipColor(int* r, int* g, int* b, int a) {
     int L = Lum(*r, *g, *b);
     int n = minimum(*r, *g, *b);
     int x = maximum(*r, *g, *b);
     int denom;
     if ((n < 0) && (denom = L - n)) { // Compute denom and make sure it's non zero
        *r = L + SkMulDiv(*r - L, L, denom);
        *g = L + SkMulDiv(*g - L, L, denom);
        *b = L + SkMulDiv(*b - L, L, denom);
     }
     if ((x > a) && (denom = x - L)) { // Compute denom and make sure it's non zero
        int numer = a - L;
        *r = L + SkMulDiv(*r - L, numer, denom);
        *g = L + SkMulDiv(*g - L, numer, denom);
        *b = L + SkMulDiv(*b - L, numer, denom);
     }
 }
 static inline void SetLum(int* r, int* g, int* b, int a, int l) {
   int d = l - Lum(*r, *g, *b);
   *r +=  d;
   *g +=  d;
   *b +=  d;
   clipColor(r, g, b, a);
 }
 // non-separable blend modes are done in non-premultiplied alpha
 #define  blendfunc_nonsep_byte(sc, dc, sa, da, blendval) \
   clamp_div255round(sc * (255 - da) +  dc * (255 - sa) + blendval)
 // kHue_Mode
 // B(Cb, Cs) = SetLum(SetSat(Cs, Sat(Cb)), Lum(Cb))
 // Create a color with the hue of the source color and the saturation and luminosity of the backdrop color.
 static SkPMColor hue_modeproc(SkPMColor src, SkPMColor dst) {
     int sr = SkGetPackedR32(src);
     int sg = SkGetPackedG32(src);
     int sb = SkGetPackedB32(src);
     int sa = SkGetPackedA32(src);
     int dr = SkGetPackedR32(dst);
     int dg = SkGetPackedG32(dst);
     int db = SkGetPackedB32(dst);
     int da = SkGetPackedA32(dst);
     int Sr, Sg, Sb;
     if(sa && da) {
         Sr = sr * sa;
         Sg = sg * sa;
         Sb = sb * sa;
         SetSat(&Sr, &Sg, &Sb, Sat(dr, dg, db) * sa);
         SetLum(&Sr, &Sg, &Sb, sa * da, Lum(dr, dg, db) * sa);
     } else {
         Sr = 0;
         Sg = 0;
         Sb = 0;
     }
     int a = srcover_byte(sa, da);
     int r = blendfunc_nonsep_byte(sr, dr, sa, da, Sr);
     int g = blendfunc_nonsep_byte(sg, dg, sa, da, Sg);
     int b = blendfunc_nonsep_byte(sb, db, sa, da, Sb);
     return SkPackARGB32(a, r, g, b);
 }
 // kSaturation_Mode
 // B(Cb, Cs) = SetLum(SetSat(Cb, Sat(Cs)), Lum(Cb))
 // Create a color with the saturation of the source color and the hue and luminosity of the backdrop color.
 static SkPMColor saturation_modeproc(SkPMColor src, SkPMColor dst) {
     int sr = SkGetPackedR32(src);
     int sg = SkGetPackedG32(src);
     int sb = SkGetPackedB32(src);
     int sa = SkGetPackedA32(src);
     int dr = SkGetPackedR32(dst);
     int dg = SkGetPackedG32(dst);
     int db = SkGetPackedB32(dst);
     int da = SkGetPackedA32(dst);
     int Dr, Dg, Db;
     if(sa && da) {
         Dr = dr * sa;
         Dg = dg * sa;
         Db = db * sa;
         SetSat(&Dr, &Dg, &Db, Sat(sr, sg, sb) * da);
         SetLum(&Dr, &Dg, &Db, sa * da, Lum(dr, dg, db) * sa);
     } else {
         Dr = 0;
         Dg = 0;
         Db = 0;
     }
     int a = srcover_byte(sa, da);
     int r = blendfunc_nonsep_byte(sr, dr, sa, da, Dr);
     int g = blendfunc_nonsep_byte(sg, dg, sa, da, Dg);
     int b = blendfunc_nonsep_byte(sb, db, sa, da, Db);
     return SkPackARGB32(a, r, g, b);
 }
 // kColor_Mode
 // B(Cb, Cs) = SetLum(Cs, Lum(Cb))
 // Create a color with the hue and saturation of the source color and the luminosity of the backdrop color.
 static SkPMColor color_modeproc(SkPMColor src, SkPMColor dst) {
     int sr = SkGetPackedR32(src);
     int sg = SkGetPackedG32(src);
     int sb = SkGetPackedB32(src);
     int sa = SkGetPackedA32(src);
     int dr = SkGetPackedR32(dst);
     int dg = SkGetPackedG32(dst);
     int db = SkGetPackedB32(dst);
     int da = SkGetPackedA32(dst);
     int Sr, Sg, Sb;
     if(sa && da) {
         Sr = sr * da;
         Sg = sg * da;
         Sb = sb * da;
         SetLum(&Sr, &Sg, &Sb, sa * da, Lum(dr, dg, db) * sa);
     } else {
         Sr = 0;
         Sg = 0;
         Sb = 0;
     }
     int a = srcover_byte(sa, da);
     int r = blendfunc_nonsep_byte(sr, dr, sa, da, Sr);
     int g = blendfunc_nonsep_byte(sg, dg, sa, da, Sg);
     int b = blendfunc_nonsep_byte(sb, db, sa, da, Sb);
     return SkPackARGB32(a, r, g, b);
 }
 // kLuminosity_Mode
 // B(Cb, Cs) = SetLum(Cb, Lum(Cs))
 // Create a color with the luminosity of the source color and the hue and saturation of the backdrop color.
 static SkPMColor luminosity_modeproc(SkPMColor src, SkPMColor dst) {
     int sr = SkGetPackedR32(src);
     int sg = SkGetPackedG32(src);
     int sb = SkGetPackedB32(src);
     int sa = SkGetPackedA32(src);
     int dr = SkGetPackedR32(dst);
     int dg = SkGetPackedG32(dst);
     int db = SkGetPackedB32(dst);
     int da = SkGetPackedA32(dst);
     int Dr, Dg, Db;
     if(sa && da) {
         Dr = dr * sa;
         Dg = dg * sa;
         Db = db * sa;
         SetLum(&Dr, &Dg, &Db, sa * da, Lum(sr, sg, sb) * da);
     } else {
         Dr = 0;
         Dg = 0;
         Db = 0;
     }
     int a = srcover_byte(sa, da);
     int r = blendfunc_nonsep_byte(sr, dr, sa, da, Dr);
     int g = blendfunc_nonsep_byte(sg, dg, sa, da, Dg);
     int b = blendfunc_nonsep_byte(sb, db, sa, da, Db);
     return SkPackARGB32(a, r, g, b);
 }
 const ProcCoeff gProcCoeffs[] = {
     { clear_modeproc,   SkXfermode::kZero_Coeff,    SkXfermode::kZero_Coeff },
     { src_modeproc,     SkXfermode::kOne_Coeff,     SkXfermode::kZero_Coeff },
     { dst_modeproc,     SkXfermode::kZero_Coeff,    SkXfermode::kOne_Coeff },
     { srcover_modeproc, SkXfermode::kOne_Coeff,     SkXfermode::kISA_Coeff },
     { dstover_modeproc, SkXfermode::kIDA_Coeff,     SkXfermode::kOne_Coeff },
     { srcin_modeproc,   SkXfermode::kDA_Coeff,      SkXfermode::kZero_Coeff },
     { dstin_modeproc,   SkXfermode::kZero_Coeff,    SkXfermode::kSA_Coeff },
     { srcout_modeproc,  SkXfermode::kIDA_Coeff,     SkXfermode::kZero_Coeff },
     { dstout_modeproc,  SkXfermode::kZero_Coeff,    SkXfermode::kISA_Coeff },
     { srcatop_modeproc, SkXfermode::kDA_Coeff,      SkXfermode::kISA_Coeff },
     { dstatop_modeproc, SkXfermode::kIDA_Coeff,     SkXfermode::kSA_Coeff },
     { xor_modeproc,     SkXfermode::kIDA_Coeff,     SkXfermode::kISA_Coeff },
     { plus_modeproc,    SkXfermode::kOne_Coeff,     SkXfermode::kOne_Coeff },
     { modulate_modeproc,SkXfermode::kZero_Coeff,    SkXfermode::kSC_Coeff },
     { screen_modeproc,  SkXfermode::kOne_Coeff,     SkXfermode::kISC_Coeff },
     { overlay_modeproc,     CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { darken_modeproc,      CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { lighten_modeproc,     CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { colordodge_modeproc,  CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { colorburn_modeproc,   CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { hardlight_modeproc,   CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { softlight_modeproc,   CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { difference_modeproc,  CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { exclusion_modeproc,   CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { multiply_modeproc,    CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { hue_modeproc,         CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { saturation_modeproc,  CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { color_modeproc,       CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
     { luminosity_modeproc,  CANNOT_USE_COEFF,       CANNOT_USE_COEFF },
 };
 ///////////////////////////////////////////////////////////////////////////////
 bool SkXfermode::asCoeff(Coeff* src, Coeff* dst) const {
     return false;
 }
 bool SkXfermode::asMode(Mode* mode) const {
     return false;
 }
 bool SkXfermode::asNewEffect(GrEffectRef** effect, GrTexture* background) const {
     return false;
 }
 bool SkXfermode::AsNewEffectOrCoeff(SkXfermode* xfermode,
                                     GrEffectRef** effect,
                                     Coeff* src,
                                     Coeff* dst,
                                     GrTexture* background) {
     if (NULL == xfermode) {
         return ModeAsCoeff(kSrcOver_Mode, src, dst);
     } else if (xfermode->asCoeff(src, dst)) {
         return true;
     } else {
         return xfermode->asNewEffect(effect, background);
     }
 }
 SkPMColor SkXfermode::xferColor(SkPMColor src, SkPMColor dst) const{
     // no-op. subclasses should override this
     return dst;
 }
 void SkXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                         const SkPMColor* SK_RESTRICT src, int count,
                         const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     if (NULL == aa) {
         for (int i = count - 1; i >= 0; --i) {
             dst[i] = this->xferColor(src[i], dst[i]);
         }
     } else {
         for (int i = count - 1; i >= 0; --i) {
             unsigned a = aa[i];
             if (0 != a) {
                 SkPMColor dstC = dst[i];
                 SkPMColor C = this->xferColor(src[i], dstC);
                 if (0xFF != a) {
                     C = SkFourByteInterp(C, dstC, a);
                 }
                 dst[i] = C;
             }
         }
     }
 }
 void SkXfermode::xfer16(uint16_t* dst,
                         const SkPMColor* SK_RESTRICT src, int count,
                         const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     if (NULL == aa) {
         for (int i = count - 1; i >= 0; --i) {
             SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
             dst[i] = SkPixel32ToPixel16_ToU16(this->xferColor(src[i], dstC));
         }
     } else {
         for (int i = count - 1; i >= 0; --i) {
             unsigned a = aa[i];
             if (0 != a) {
                 SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
                 SkPMColor C = this->xferColor(src[i], dstC);
                 if (0xFF != a) {
                     C = SkFourByteInterp(C, dstC, a);
                 }
                 dst[i] = SkPixel32ToPixel16_ToU16(C);
             }
         }
     }
 }
 void SkXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                         const SkPMColor src[], int count,
                         const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     if (NULL == aa) {
         for (int i = count - 1; i >= 0; --i) {
             SkPMColor res = this->xferColor(src[i], (dst[i] << SK_A32_SHIFT));
             dst[i] = SkToU8(SkGetPackedA32(res));
         }
     } else {
         for (int i = count - 1; i >= 0; --i) {
             unsigned a = aa[i];
             if (0 != a) {
                 SkAlpha dstA = dst[i];
                 unsigned A = SkGetPackedA32(this->xferColor(src[i],
                                             (SkPMColor)(dstA << SK_A32_SHIFT)));
                 if (0xFF != a) {
                     A = SkAlphaBlend(A, dstA, SkAlpha255To256(a));
                 }
                 dst[i] = SkToU8(A);
             }
         }
     }
 }
 ///////////////////////////////////////////////////////////////////////////////
 void SkProcXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                             const SkPMColor* SK_RESTRICT src, int count,
                             const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     SkXfermodeProc proc = fProc;
     if (NULL != proc) {
         if (NULL == aa) {
             for (int i = count - 1; i >= 0; --i) {
                 dst[i] = proc(src[i], dst[i]);
             }
         } else {
             for (int i = count - 1; i >= 0; --i) {
                 unsigned a = aa[i];
                 if (0 != a) {
                     SkPMColor dstC = dst[i];
                     SkPMColor C = proc(src[i], dstC);
                     if (a != 0xFF) {
                         C = SkFourByteInterp(C, dstC, a);
                     }
                     dst[i] = C;
                 }
             }
         }
     }
 }
 void SkProcXfermode::xfer16(uint16_t* SK_RESTRICT dst,
                             const SkPMColor* SK_RESTRICT src, int count,
                             const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     SkXfermodeProc proc = fProc;
     if (NULL != proc) {
         if (NULL == aa) {
             for (int i = count - 1; i >= 0; --i) {
                 SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
                 dst[i] = SkPixel32ToPixel16_ToU16(proc(src[i], dstC));
             }
         } else {
             for (int i = count - 1; i >= 0; --i) {
                 unsigned a = aa[i];
                 if (0 != a) {
                     SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
                     SkPMColor C = proc(src[i], dstC);
                     if (0xFF != a) {
                         C = SkFourByteInterp(C, dstC, a);
                     }
                     dst[i] = SkPixel32ToPixel16_ToU16(C);
                 }
             }
         }
     }
 }
 void SkProcXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                             const SkPMColor* SK_RESTRICT src, int count,
                             const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     SkXfermodeProc proc = fProc;
     if (NULL != proc) {
         if (NULL == aa) {
             for (int i = count - 1; i >= 0; --i) {
                 SkPMColor res = proc(src[i], dst[i] << SK_A32_SHIFT);
                 dst[i] = SkToU8(SkGetPackedA32(res));
             }
         } else {
             for (int i = count - 1; i >= 0; --i) {
                 unsigned a = aa[i];
                 if (0 != a) {
                     SkAlpha dstA = dst[i];
                     SkPMColor res = proc(src[i], dstA << SK_A32_SHIFT);
                     unsigned A = SkGetPackedA32(res);
                     if (0xFF != a) {
                         A = SkAlphaBlend(A, dstA, SkAlpha255To256(a));
                     }
                     dst[i] = SkToU8(A);
                 }
             }
         }
     }
 }
 SkProcXfermode::SkProcXfermode(SkReadBuffer& buffer)
         : SkXfermode(buffer) {
     fProc = NULL;
     if (!buffer.isCrossProcess()) {
         fProc = (SkXfermodeProc)buffer.readFunctionPtr();
     }
 }
 void SkProcXfermode::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     if (!buffer.isCrossProcess()) {
         buffer.writeFunctionPtr((void*)fProc);
     }
 }
 #ifndef SK_IGNORE_TO_STRING
 void SkProcXfermode::toString(SkString* str) const {
     str->appendf("SkProcXfermode: %p", fProc);
 }
 #endif
 //////////////////////////////////////////////////////////////////////////////
 #if SK_SUPPORT_GPU
 #include "GrEffect.h"
 #include "GrCoordTransform.h"
 #include "GrEffectUnitTest.h"
 #include "GrTBackendEffectFactory.h"
 #include "gl/GrGLEffect.h"
 /**
  * GrEffect that implements the all the separable xfer modes that cannot be expressed as Coeffs.
  */
 class XferEffect : public GrEffect {
 public:
     static bool IsSupportedMode(SkXfermode::Mode mode) {
         return mode > SkXfermode::kLastCoeffMode && mode <= SkXfermode::kLastMode;
     }
     static GrEffectRef* Create(SkXfermode::Mode mode, GrTexture* background) {
         if (!IsSupportedMode(mode)) {
             return NULL;
         } else {
             AutoEffectUnref effect(SkNEW_ARGS(XferEffect, (mode, background)));
             return CreateEffectRef(effect);
         }
     }
     virtual void getConstantColorComponents(GrColor* color,
                                             uint32_t* validFlags) const SK_OVERRIDE {
         *validFlags = 0;
     }
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
         return GrTBackendEffectFactory<XferEffect>::getInstance();
     }
     static const char* Name() { return "XferEffect"; }
     SkXfermode::Mode mode() const { return fMode; }
     const GrTextureAccess&  backgroundAccess() const { return fBackgroundAccess; }
     class GLEffect : public GrGLEffect {
     public:
         GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
             : GrGLEffect(factory) {
         }
         virtual void emitCode(GrGLShaderBuilder* builder,
                               const GrDrawEffect& drawEffect,
                               EffectKey key,
                               const char* outputColor,
                               const char* inputColor,
                               const TransformedCoordsArray& coords,
                               const TextureSamplerArray& samplers) SK_OVERRIDE {
             SkXfermode::Mode mode = drawEffect.castEffect<XferEffect>().mode();
             const GrTexture* backgroundTex = drawEffect.castEffect<XferEffect>().backgroundAccess().getTexture();
             const char* dstColor;
             if (backgroundTex) {
                 dstColor = "bgColor";
                 builder->fsCodeAppendf("\t\tvec4 %s = ", dstColor);
                 builder->fsAppendTextureLookup(samplers[0], coords[0].c_str(), coords[0].type());
                 builder->fsCodeAppendf(";\n");
             } else {
                 dstColor = builder->dstColor();
             }
             SkASSERT(NULL != dstColor);
             // We don't try to optimize for this case at all
             if (NULL == inputColor) {
                 builder->fsCodeAppendf("\t\tconst vec4 ones = vec4(1);\n");
                 inputColor = "ones";
             }
             builder->fsCodeAppendf("\t\t// SkXfermode::Mode: %s\n", SkXfermode::ModeName(mode));
             // These all perform src-over on the alpha channel.
             builder->fsCodeAppendf("\t\t%s.a = %s.a + (1.0 - %s.a) * %s.a;\n",
                                     outputColor, inputColor, inputColor, dstColor);
             switch (mode) {
                 case SkXfermode::kOverlay_Mode:
                     // Overlay is Hard-Light with the src and dst reversed
                     HardLight(builder, outputColor, dstColor, inputColor);
                     break;
                 case SkXfermode::kDarken_Mode:
                     builder->fsCodeAppendf("\t\t%s.rgb = min((1.0 - %s.a) * %s.rgb + %s.rgb, "
                                                             "(1.0 - %s.a) * %s.rgb + %s.rgb);\n",
                                             outputColor,
                                             inputColor, dstColor, inputColor,
                                             dstColor, inputColor, dstColor);
                     break;
                 case SkXfermode::kLighten_Mode:
                     builder->fsCodeAppendf("\t\t%s.rgb = max((1.0 - %s.a) * %s.rgb + %s.rgb, "
                                                             "(1.0 - %s.a) * %s.rgb + %s.rgb);\n",
                                             outputColor,
                                             inputColor, dstColor, inputColor,
                                             dstColor, inputColor, dstColor);
                     break;
                 case SkXfermode::kColorDodge_Mode:
                     ColorDodgeComponent(builder, outputColor, inputColor, dstColor, 'r');
                     ColorDodgeComponent(builder, outputColor, inputColor, dstColor, 'g');
                     ColorDodgeComponent(builder, outputColor, inputColor, dstColor, 'b');
                     break;
                 case SkXfermode::kColorBurn_Mode:
                     ColorBurnComponent(builder, outputColor, inputColor, dstColor, 'r');
                     ColorBurnComponent(builder, outputColor, inputColor, dstColor, 'g');
                     ColorBurnComponent(builder, outputColor, inputColor, dstColor, 'b');
                     break;
                 case SkXfermode::kHardLight_Mode:
                     HardLight(builder, outputColor, inputColor, dstColor);
                     break;
                 case SkXfermode::kSoftLight_Mode:
                     builder->fsCodeAppendf("\t\tif (0.0 == %s.a) {\n", dstColor);
                     builder->fsCodeAppendf("\t\t\t%s.rgba = %s;\n", outputColor, inputColor);
                     builder->fsCodeAppendf("\t\t} else {\n");
                     SoftLightComponentPosDstAlpha(builder, outputColor, inputColor, dstColor, 'r');
                     SoftLightComponentPosDstAlpha(builder, outputColor, inputColor, dstColor, 'g');
                     SoftLightComponentPosDstAlpha(builder, outputColor, inputColor, dstColor, 'b');
                     builder->fsCodeAppendf("\t\t}\n");
                     break;
                 case SkXfermode::kDifference_Mode:
                     builder->fsCodeAppendf("\t\t%s.rgb = %s.rgb + %s.rgb -"
                                                        "2.0 * min(%s.rgb * %s.a, %s.rgb * %s.a);\n",
                                            outputColor, inputColor, dstColor, inputColor, dstColor,
                                            dstColor, inputColor);
                     break;
                 case SkXfermode::kExclusion_Mode:
                     builder->fsCodeAppendf("\t\t%s.rgb = %s.rgb + %s.rgb - "
                                                         "2.0 * %s.rgb * %s.rgb;\n",
                                            outputColor, dstColor, inputColor, dstColor, inputColor);
                     break;
                 case SkXfermode::kMultiply_Mode:
                     builder->fsCodeAppendf("\t\t%s.rgb = (1.0 - %s.a) * %s.rgb + "
                                                         "(1.0 - %s.a) * %s.rgb + "
                                                          "%s.rgb * %s.rgb;\n",
                                            outputColor, inputColor, dstColor, dstColor, inputColor,
                                            inputColor, dstColor);
                     break;
                 case SkXfermode::kHue_Mode: {
                     //  SetLum(SetSat(S * Da, Sat(D * Sa)), Sa*Da, D*Sa) + (1 - Sa) * D + (1 - Da) * S
                     SkString setSat, setLum;
                     AddSatFunction(builder, &setSat);
                     AddLumFunction(builder, &setLum);
                     builder->fsCodeAppendf("\t\tvec4 dstSrcAlpha = %s * %s.a;\n",
                                            dstColor, inputColor);
                     builder->fsCodeAppendf("\t\t%s.rgb = %s(%s(%s.rgb * %s.a, dstSrcAlpha.rgb), dstSrcAlpha.a, dstSrcAlpha.rgb);\n",
                                            outputColor, setLum.c_str(), setSat.c_str(), inputColor,
                                            dstColor);
                     builder->fsCodeAppendf("\t\t%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;\n",
                                            outputColor, inputColor, dstColor, dstColor, inputColor);
                     break;
                 }
                 case SkXfermode::kSaturation_Mode: {
                     // SetLum(SetSat(D * Sa, Sat(S * Da)), Sa*Da, D*Sa)) + (1 - Sa) * D + (1 - Da) * S
                     SkString setSat, setLum;
                     AddSatFunction(builder, &setSat);
                     AddLumFunction(builder, &setLum);
                     builder->fsCodeAppendf("\t\tvec4 dstSrcAlpha = %s * %s.a;\n",
                                            dstColor, inputColor);
                     builder->fsCodeAppendf("\t\t%s.rgb = %s(%s(dstSrcAlpha.rgb, %s.rgb * %s.a), dstSrcAlpha.a, dstSrcAlpha.rgb);\n",
                                            outputColor, setLum.c_str(), setSat.c_str(), inputColor,
                                            dstColor);
                     builder->fsCodeAppendf("\t\t%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;\n",
                                            outputColor, inputColor, dstColor, dstColor, inputColor);
                     break;
                 }
                 case SkXfermode::kColor_Mode: {
                     //  SetLum(S * Da, Sa* Da, D * Sa) + (1 - Sa) * D + (1 - Da) * S
                     SkString setLum;
                     AddLumFunction(builder, &setLum);
                     builder->fsCodeAppendf("\t\tvec4 srcDstAlpha = %s * %s.a;\n",
                                            inputColor, dstColor);
                     builder->fsCodeAppendf("\t\t%s.rgb = %s(srcDstAlpha.rgb, srcDstAlpha.a, %s.rgb * %s.a);\n",
                                            outputColor, setLum.c_str(), dstColor, inputColor);
                     builder->fsCodeAppendf("\t\t%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;\n",
                                            outputColor, inputColor, dstColor, dstColor, inputColor);
                     break;
                 }
                 case SkXfermode::kLuminosity_Mode: {
                     //  SetLum(D * Sa, Sa* Da, S * Da) + (1 - Sa) * D + (1 - Da) * S
                     SkString setLum;
                     AddLumFunction(builder, &setLum);
                     builder->fsCodeAppendf("\t\tvec4 srcDstAlpha = %s * %s.a;\n",
                                            inputColor, dstColor);
                     builder->fsCodeAppendf("\t\t%s.rgb = %s(%s.rgb * %s.a, srcDstAlpha.a, srcDstAlpha.rgb);\n",
                                            outputColor, setLum.c_str(), dstColor, inputColor);
                     builder->fsCodeAppendf("\t\t%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;\n",
                                            outputColor, inputColor, dstColor, dstColor, inputColor);
                     break;
                 }
                 default:
                     GrCrash("Unknown XferEffect mode.");
                     break;
             }
         }
         static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
             return drawEffect.castEffect<XferEffect>().mode();
         }
     private:
         static void HardLight(GrGLShaderBuilder* builder,
                               const char* final,
                               const char* src,
                               const char* dst) {
             static const char kComponents[] = {'r', 'g', 'b'};
             for (size_t i = 0; i < SK_ARRAY_COUNT(kComponents); ++i) {
                 char component = kComponents[i];
                 builder->fsCodeAppendf("\t\tif (2.0 * %s.%c <= %s.a) {\n", src, component, src);
                 builder->fsCodeAppendf("\t\t\t%s.%c = 2.0 * %s.%c * %s.%c;\n", final, component, src, component, dst, component);
                 builder->fsCodeAppend("\t\t} else {\n");
                 builder->fsCodeAppendf("\t\t\t%s.%c = %s.a * %s.a - 2.0 * (%s.a - %s.%c) * (%s.a - %s.%c);\n",
                                        final, component, src, dst, dst, dst, component, src, src, component);
                 builder->fsCodeAppend("\t\t}\n");
             }
             builder->fsCodeAppendf("\t\t%s.rgb += %s.rgb * (1.0 - %s.a) + %s.rgb * (1.0 - %s.a);\n",
                                    final, src, dst, dst, src);
         }
         // Does one component of color-dodge
         static void ColorDodgeComponent(GrGLShaderBuilder* builder,
                                         const char* final,
                                         const char* src,
                                         const char* dst,
                                         const char component) {
             builder->fsCodeAppendf("\t\tif (0.0 == %s.%c) {\n", dst, component);
             builder->fsCodeAppendf("\t\t\t%s.%c = %s.%c * (1.0 - %s.a);\n",
                                    final, component, src, component, dst);
             builder->fsCodeAppend("\t\t} else {\n");
             builder->fsCodeAppendf("\t\t\tfloat d = %s.a - %s.%c;\n", src, src, component);
             builder->fsCodeAppend("\t\t\tif (0.0 == d) {\n");
             builder->fsCodeAppendf("\t\t\t\t%s.%c = %s.a * %s.a + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);\n",
                                    final, component, src, dst, src, component, dst, dst, component,
                                    src);
             builder->fsCodeAppend("\t\t\t} else {\n");
             builder->fsCodeAppendf("\t\t\t\td = min(%s.a, %s.%c * %s.a / d);\n",
                                    dst, dst, component, src);
             builder->fsCodeAppendf("\t\t\t\t%s.%c = d * %s.a + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);\n",
                                    final, component, src, src, component, dst, dst, component, src);
             builder->fsCodeAppend("\t\t\t}\n");
             builder->fsCodeAppend("\t\t}\n");
         }
         // Does one component of color-burn
         static void ColorBurnComponent(GrGLShaderBuilder* builder,
                                        const char* final,
                                        const char* src,
                                        const char* dst,
                                        const char component) {
             builder->fsCodeAppendf("\t\tif (%s.a == %s.%c) {\n", dst, dst, component);
             builder->fsCodeAppendf("\t\t\t%s.%c = %s.a * %s.a + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);\n",
                                    final, component, src, dst, src, component, dst, dst, component,
                                    src);
             builder->fsCodeAppendf("\t\t} else if (0.0 == %s.%c) {\n", src, component);
             builder->fsCodeAppendf("\t\t\t%s.%c = %s.%c * (1.0 - %s.a);\n",
                                    final, component, dst, component, src);
             builder->fsCodeAppend("\t\t} else {\n");
             builder->fsCodeAppendf("\t\t\tfloat d = max(0.0, %s.a - (%s.a - %s.%c) * %s.a / %s.%c);\n",
                                    dst, dst, dst, component, src, src, component);
             builder->fsCodeAppendf("\t\t\t%s.%c = %s.a * d + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);\n",
                                    final, component, src, src, component, dst, dst, component, src);
             builder->fsCodeAppend("\t\t}\n");
         }
         // Does one component of soft-light. Caller should have already checked that dst alpha > 0.
         static void SoftLightComponentPosDstAlpha(GrGLShaderBuilder* builder,
                                                   const char* final,
                                                   const char* src,
                                                   const char* dst,
                                                   const char component) {
             // if (2S < Sa)
             builder->fsCodeAppendf("\t\t\tif (2.0 * %s.%c <= %s.a) {\n", src, component, src);
             // (D^2 (Sa-2 S))/Da+(1-Da) S+D (-Sa+2 S+1)
             builder->fsCodeAppendf("\t\t\t\t%s.%c = (%s.%c*%s.%c*(%s.a - 2.0*%s.%c)) / %s.a + (1.0 - %s.a) * %s.%c + %s.%c*(-%s.a + 2.0*%s.%c + 1.0);\n",
                                    final, component, dst, component, dst, component, src, src,
                                    component, dst, dst, src, component, dst, component, src, src,
                                    component);
             // else if (4D < Da)
             builder->fsCodeAppendf("\t\t\t} else if (4.0 * %s.%c <= %s.a) {\n",
                                    dst, component, dst);
             builder->fsCodeAppendf("\t\t\t\tfloat DSqd = %s.%c * %s.%c;\n",
                                    dst, component, dst, component);
             builder->fsCodeAppendf("\t\t\t\tfloat DCub = DSqd * %s.%c;\n", dst, component);
             builder->fsCodeAppendf("\t\t\t\tfloat DaSqd = %s.a * %s.a;\n", dst, dst);
             builder->fsCodeAppendf("\t\t\t\tfloat DaCub = DaSqd * %s.a;\n", dst);
             // (Da^3 (-S)+Da^2 (S-D (3 Sa-6 S-1))+12 Da D^2 (Sa-2 S)-16 D^3 (Sa-2 S))/Da^2
             builder->fsCodeAppendf("\t\t\t\t%s.%c = (-DaCub*%s.%c + DaSqd*(%s.%c - %s.%c * (3.0*%s.a - 6.0*%s.%c - 1.0)) + 12.0*%s.a*DSqd*(%s.a - 2.0*%s.%c) - 16.0*DCub * (%s.a - 2.0*%s.%c)) / DaSqd;\n",
                                    final, component, src, component, src, component, dst, component,
                                    src, src, component, dst, src, src, component, src, src,
                                    component);
             builder->fsCodeAppendf("\t\t\t} else {\n");
             // -sqrt(Da * D) (Sa-2 S)-Da S+D (Sa-2 S+1)+S
             builder->fsCodeAppendf("\t\t\t\t%s.%c = -sqrt(%s.a*%s.%c)*(%s.a - 2.0*%s.%c) - %s.a*%s.%c + %s.%c*(%s.a - 2.0*%s.%c + 1.0) + %s.%c;\n",
                                     final, component, dst, dst, component, src, src, component, dst,
                                     src, component, dst, component, src, src, component, src,
                                     component);
             builder->fsCodeAppendf("\t\t\t}\n");
         }
         // Adds a function that takes two colors and an alpha as input. It produces a color with the
         // hue and saturation of the first color, the luminosity of the second color, and the input
         // alpha. It has this signature:
         //      vec3 set_luminance(vec3 hueSatColor, float alpha, vec3 lumColor).
         static void AddLumFunction(GrGLShaderBuilder* builder, SkString* setLumFunction) {
             // Emit a helper that gets the luminance of a color.
             SkString getFunction;
             GrGLShaderVar getLumArgs[] = {
                 GrGLShaderVar("color", kVec3f_GrSLType),
             };
             SkString getLumBody("\treturn dot(vec3(0.3, 0.59, 0.11), color);\n");
             builder->fsEmitFunction(kFloat_GrSLType,
                                     "luminance",
                                     SK_ARRAY_COUNT(getLumArgs), getLumArgs,
                                     getLumBody.c_str(),
                                     &getFunction);
             // Emit the set luminance function.
             GrGLShaderVar setLumArgs[] = {
                 GrGLShaderVar("hueSat", kVec3f_GrSLType),
                 GrGLShaderVar("alpha", kFloat_GrSLType),
                 GrGLShaderVar("lumColor", kVec3f_GrSLType),
             };
             SkString setLumBody;
             setLumBody.printf("\tfloat diff = %s(lumColor - hueSat);\n", getFunction.c_str());
             setLumBody.append("\tvec3 outColor = hueSat + diff;\n");
             setLumBody.appendf("\tfloat outLum = %s(outColor);\n", getFunction.c_str());
             setLumBody.append("\tfloat minComp = min(min(outColor.r, outColor.g), outColor.b);\n"
                               "\tfloat maxComp = max(max(outColor.r, outColor.g), outColor.b);\n"
                               "\tif (minComp < 0.0) {\n"
                               "\t\toutColor = outLum + ((outColor - vec3(outLum, outLum, outLum)) * outLum) / (outLum - minComp);\n"
                               "\t}\n"
                               "\tif (maxComp > alpha) {\n"
                               "\t\toutColor = outLum + ((outColor - vec3(outLum, outLum, outLum)) * (alpha - outLum)) / (maxComp - outLum);\n"
                               "\t}\n"
                               "\treturn outColor;\n");
             builder->fsEmitFunction(kVec3f_GrSLType,
                                     "set_luminance",
                                     SK_ARRAY_COUNT(setLumArgs), setLumArgs,
                                     setLumBody.c_str(),
                                     setLumFunction);
         }
         // Adds a function that creates a color with the hue and luminosity of one input color and
         // the saturation of another color. It will have this signature:
         //      float set_saturation(vec3 hueLumColor, vec3 satColor)
         static void AddSatFunction(GrGLShaderBuilder* builder, SkString* setSatFunction) {
             // Emit a helper that gets the saturation of a color
             SkString getFunction;
             GrGLShaderVar getSatArgs[] = { GrGLShaderVar("color", kVec3f_GrSLType) };
             SkString getSatBody;
             getSatBody.printf("\treturn max(max(color.r, color.g), color.b) - "
                               "min(min(color.r, color.g), color.b);\n");
             builder->fsEmitFunction(kFloat_GrSLType,
                                     "saturation",
                                     SK_ARRAY_COUNT(getSatArgs), getSatArgs,
                                     getSatBody.c_str(),
                                     &getFunction);
             // Emit a helper that sets the saturation given sorted input channels. This used
             // to use inout params for min, mid, and max components but that seems to cause
             // problems on PowerVR drivers. So instead it returns a vec3 where r, g ,b are the
             // adjusted min, mid, and max inputs, respectively.
             SkString helperFunction;
             GrGLShaderVar helperArgs[] = {
                 GrGLShaderVar("minComp", kFloat_GrSLType),
                 GrGLShaderVar("midComp", kFloat_GrSLType),
                 GrGLShaderVar("maxComp", kFloat_GrSLType),
                 GrGLShaderVar("sat", kFloat_GrSLType),
             };
             static const char kHelperBody[] = "\tif (minComp < maxComp) {\n"
                                               "\t\tvec3 result;\n"
                                               "\t\tresult.r = 0.0;\n"
                                               "\t\tresult.g = sat * (midComp - minComp) / (maxComp - minComp);\n"
                                               "\t\tresult.b = sat;\n"
                                               "\t\treturn result;\n"
                                               "\t} else {\n"
                                               "\t\treturn vec3(0, 0, 0);\n"
                                               "\t}\n";
             builder->fsEmitFunction(kVec3f_GrSLType,
                                     "set_saturation_helper",
                                     SK_ARRAY_COUNT(helperArgs), helperArgs,
                                     kHelperBody,
                                     &helperFunction);
             GrGLShaderVar setSatArgs[] = {
                 GrGLShaderVar("hueLumColor", kVec3f_GrSLType),
                 GrGLShaderVar("satColor", kVec3f_GrSLType),
             };
             const char* helpFunc = helperFunction.c_str();
             SkString setSatBody;
             setSatBody.appendf("\tfloat sat = %s(satColor);\n"
                                "\tif (hueLumColor.r <= hueLumColor.g) {\n"
                                "\t\tif (hueLumColor.g <= hueLumColor.b) {\n"
                                "\t\t\thueLumColor.rgb = %s(hueLumColor.r, hueLumColor.g, hueLumColor.b, sat);\n"
                                "\t\t} else if (hueLumColor.r <= hueLumColor.b) {\n"
                                "\t\t\thueLumColor.rbg = %s(hueLumColor.r, hueLumColor.b, hueLumColor.g, sat);\n"
                                "\t\t} else {\n"
                                "\t\t\thueLumColor.brg = %s(hueLumColor.b, hueLumColor.r, hueLumColor.g, sat);\n"
                                "\t\t}\n"
                                "\t} else if (hueLumColor.r <= hueLumColor.b) {\n"
                                "\t\thueLumColor.grb = %s(hueLumColor.g, hueLumColor.r, hueLumColor.b, sat);\n"
                                "\t} else if (hueLumColor.g <= hueLumColor.b) {\n"
                                "\t\thueLumColor.gbr = %s(hueLumColor.g, hueLumColor.b, hueLumColor.r, sat);\n"
                                "\t} else {\n"
                                "\t\thueLumColor.bgr = %s(hueLumColor.b, hueLumColor.g, hueLumColor.r, sat);\n"
                                "\t}\n"
                                "\treturn hueLumColor;\n",
                                getFunction.c_str(), helpFunc, helpFunc, helpFunc, helpFunc,
                                helpFunc, helpFunc);
             builder->fsEmitFunction(kVec3f_GrSLType,
                                     "set_saturation",
                                     SK_ARRAY_COUNT(setSatArgs), setSatArgs,
                                     setSatBody.c_str(),
                                     setSatFunction);
         }
         typedef GrGLEffect INHERITED;
     };
     GR_DECLARE_EFFECT_TEST;
 private:
     XferEffect(SkXfermode::Mode mode, GrTexture* background)
         : fMode(mode) {
         if (background) {
             fBackgroundTransform.reset(kLocal_GrCoordSet, background);
             this->addCoordTransform(&fBackgroundTransform);
             fBackgroundAccess.reset(background);
             this->addTextureAccess(&fBackgroundAccess);
         } else {
             this->setWillReadDstColor();
         }
     }
     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
         const XferEffect& s = CastEffect<XferEffect>(other);
         return fMode == s.fMode &&
                fBackgroundAccess.getTexture() == s.fBackgroundAccess.getTexture();
     }
     SkXfermode::Mode fMode;
     GrCoordTransform fBackgroundTransform;
     GrTextureAccess  fBackgroundAccess;
     typedef GrEffect INHERITED;
 };
 GR_DEFINE_EFFECT_TEST(XferEffect);
 GrEffectRef* XferEffect::TestCreate(SkRandom* rand,
                                     GrContext*,
                                     const GrDrawTargetCaps&,
                                     GrTexture*[]) {
     int mode = rand->nextRangeU(SkXfermode::kLastCoeffMode + 1, SkXfermode::kLastSeparableMode);
     AutoEffectUnref gEffect(SkNEW_ARGS(XferEffect, (static_cast<SkXfermode::Mode>(mode), NULL)));
     return CreateEffectRef(gEffect);
 }
 #endif
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 SkProcCoeffXfermode::SkProcCoeffXfermode(SkReadBuffer& buffer) : INHERITED(buffer) {
     uint32_t mode32 = buffer.read32() % SK_ARRAY_COUNT(gProcCoeffs);
     if (mode32 >= SK_ARRAY_COUNT(gProcCoeffs)) {
         // out of range, just set to something harmless
         mode32 = SkXfermode::kSrcOut_Mode;
     }
     fMode = (SkXfermode::Mode)mode32;
     const ProcCoeff& rec = gProcCoeffs[fMode];
     // these may be valid, or may be CANNOT_USE_COEFF
     fSrcCoeff = rec.fSC;
     fDstCoeff = rec.fDC;
     // now update our function-ptr in the super class
     this->INHERITED::setProc(rec.fProc);
 }
 bool SkProcCoeffXfermode::asMode(Mode* mode) const {
     if (mode) {
         *mode = fMode;
     }
     return true;
 }
 bool SkProcCoeffXfermode::asCoeff(Coeff* sc, Coeff* dc) const {
     if (CANNOT_USE_COEFF == fSrcCoeff) {
         return false;
     }
     if (sc) {
         *sc = fSrcCoeff;
     }
     if (dc) {
         *dc = fDstCoeff;
     }
     return true;
 }
 #if SK_SUPPORT_GPU
 bool SkProcCoeffXfermode::asNewEffect(GrEffectRef** effect,
                                       GrTexture* background) const {
     if (XferEffect::IsSupportedMode(fMode)) {
         if (NULL != effect) {
             *effect = XferEffect::Create(fMode, background);
             SkASSERT(NULL != *effect);
         }
         return true;
     }
     return false;
 }
 #endif
 void SkProcCoeffXfermode::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.write32(fMode);
 }
 const char* SkXfermode::ModeName(Mode mode) {
     SkASSERT((unsigned) mode <= (unsigned)kLastMode);
     const char* gModeStrings[] = {
         "Clear", "Src", "Dst", "SrcOver", "DstOver", "SrcIn", "DstIn",
         "SrcOut", "DstOut", "SrcATop", "DstATop", "Xor", "Plus",
         "Modulate", "Screen", "Overlay", "Darken", "Lighten", "ColorDodge",
         "ColorBurn", "HardLight", "SoftLight", "Difference", "Exclusion",
         "Multiply", "Hue", "Saturation", "Color",  "Luminosity"
     };
     return gModeStrings[mode];
     SK_COMPILE_ASSERT(SK_ARRAY_COUNT(gModeStrings) == kLastMode + 1, mode_count);
 }
 #ifndef SK_IGNORE_TO_STRING
 void SkProcCoeffXfermode::toString(SkString* str) const {
     str->append("SkProcCoeffXfermode: ");
     str->append("mode: ");
     str->append(ModeName(fMode));
     static const char* gCoeffStrings[kCoeffCount] = {
         "Zero", "One", "SC", "ISC", "DC", "IDC", "SA", "ISA", "DA", "IDA"
     };
     str->append(" src: ");
     if (CANNOT_USE_COEFF == fSrcCoeff) {
         str->append("can't use");
     } else {
         str->append(gCoeffStrings[fSrcCoeff]);
     }
     str->append(" dst: ");
     if (CANNOT_USE_COEFF == fDstCoeff) {
         str->append("can't use");
     } else {
         str->append(gCoeffStrings[fDstCoeff]);
     }
 }
 #endif
 ///////////////////////////////////////////////////////////////////////////////
 class SkClearXfermode : public SkProcCoeffXfermode {
 public:
     static SkClearXfermode* Create(const ProcCoeff& rec) {
         return SkNEW_ARGS(SkClearXfermode, (rec));
     }
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkClearXfermode)
 private:
     SkClearXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kClear_Mode) {}
     SkClearXfermode(SkReadBuffer& buffer)
         : SkProcCoeffXfermode(buffer) {}
     typedef SkProcCoeffXfermode INHERITED;
 };
 void SkClearXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT, int count,
                              const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && count >= 0);
     if (NULL == aa) {
         memset(dst, 0, count << 2);
     } else {
         for (int i = count - 1; i >= 0; --i) {
             unsigned a = aa[i];
             if (0xFF == a) {
                 dst[i] = 0;
             } else if (a != 0) {
                 dst[i] = SkAlphaMulQ(dst[i], SkAlpha255To256(255 - a));
             }
         }
     }
 }
 void SkClearXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT, int count,
                              const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && count >= 0);
     if (NULL == aa) {
         memset(dst, 0, count);
     } else {
         for (int i = count - 1; i >= 0; --i) {
             unsigned a = aa[i];
             if (0xFF == a) {
                 dst[i] = 0;
             } else if (0 != a) {
                 dst[i] = SkAlphaMulAlpha(dst[i], 255 - a);
             }
         }
     }
 }
 #ifndef SK_IGNORE_TO_STRING
 void SkClearXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 ///////////////////////////////////////////////////////////////////////////////
 class SkSrcXfermode : public SkProcCoeffXfermode {
 public:
     static SkSrcXfermode* Create(const ProcCoeff& rec) {
         return SkNEW_ARGS(SkSrcXfermode, (rec));
     }
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSrcXfermode)
 private:
     SkSrcXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kSrc_Mode) {}
     SkSrcXfermode(SkReadBuffer& buffer)
         : SkProcCoeffXfermode(buffer) {}
     typedef SkProcCoeffXfermode INHERITED;
 };
 void SkSrcXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                            const SkPMColor* SK_RESTRICT src, int count,
                            const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     if (NULL == aa) {
         memcpy(dst, src, count << 2);
     } else {
         for (int i = count - 1; i >= 0; --i) {
             unsigned a = aa[i];
             if (a == 0xFF) {
                 dst[i] = src[i];
             } else if (a != 0) {
                 dst[i] = SkFourByteInterp(src[i], dst[i], a);
             }
         }
     }
 }
 void SkSrcXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
                            const SkPMColor* SK_RESTRICT src, int count,
                            const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
     if (NULL == aa) {
         for (int i = count - 1; i >= 0; --i) {
             dst[i] = SkToU8(SkGetPackedA32(src[i]));
         }
     } else {
         for (int i = count - 1; i >= 0; --i) {
             unsigned a = aa[i];
             if (0 != a) {
                 unsigned srcA = SkGetPackedA32(src[i]);
                 if (a == 0xFF) {
                     dst[i] = SkToU8(srcA);
                 } else {
                     dst[i] = SkToU8(SkAlphaBlend(srcA, dst[i], a));
                 }
             }
         }
     }
 }
 #ifndef SK_IGNORE_TO_STRING
 void SkSrcXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 ///////////////////////////////////////////////////////////////////////////////
 class SkDstInXfermode : public SkProcCoeffXfermode {
 public:
     static SkDstInXfermode* Create(const ProcCoeff& rec) {
         return SkNEW_ARGS(SkDstInXfermode, (rec));
     }
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDstInXfermode)
 private:
     SkDstInXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kDstIn_Mode) {}
     SkDstInXfermode(SkReadBuffer& buffer) : INHERITED(buffer) {}
     typedef SkProcCoeffXfermode INHERITED;
 };
 void SkDstInXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT src, int count,
                              const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src);
     if (count <= 0) {
         return;
     }
     if (NULL != aa) {
         return this->INHERITED::xfer32(dst, src, count, aa);
     }
     do {
         unsigned a = SkGetPackedA32(*src);
         *dst = SkAlphaMulQ(*dst, SkAlpha255To256(a));
         dst++;
         src++;
     } while (--count != 0);
 }
 #ifndef SK_IGNORE_TO_STRING
 void SkDstInXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 ///////////////////////////////////////////////////////////////////////////////
 class SkDstOutXfermode : public SkProcCoeffXfermode {
 public:
     static SkDstOutXfermode* Create(const ProcCoeff& rec) {
         return SkNEW_ARGS(SkDstOutXfermode, (rec));
     }
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDstOutXfermode)
 private:
     SkDstOutXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kDstOut_Mode) {}
     SkDstOutXfermode(SkReadBuffer& buffer)
         : INHERITED(buffer) {}
     typedef SkProcCoeffXfermode INHERITED;
 };
 void SkDstOutXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                               const SkPMColor* SK_RESTRICT src, int count,
                               const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src);
     if (count <= 0) {
         return;
     }
     if (NULL != aa) {
         return this->INHERITED::xfer32(dst, src, count, aa);
     }
     do {
         unsigned a = SkGetPackedA32(*src);
         *dst = SkAlphaMulQ(*dst, SkAlpha255To256(255 - a));
         dst++;
         src++;
     } while (--count != 0);
 }
 #ifndef SK_IGNORE_TO_STRING
 void SkDstOutXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 ///////////////////////////////////////////////////////////////////////////////
 SK_DECLARE_STATIC_MUTEX(gCachedXfermodesMutex);
 static SkXfermode* gCachedXfermodes[SkXfermode::kLastMode + 1];
 void SkXfermode::Term() {
     SkAutoMutexAcquire ac(gCachedXfermodesMutex);
     for (size_t i = 0; i < SK_ARRAY_COUNT(gCachedXfermodes); ++i) {
         SkSafeUnref(gCachedXfermodes[i]);
         gCachedXfermodes[i] = NULL;
     }
 }
 extern SkProcCoeffXfermode* SkPlatformXfermodeFactory(const ProcCoeff& rec,
                                                       SkXfermode::Mode mode);
 extern SkXfermodeProc SkPlatformXfermodeProcFactory(SkXfermode::Mode mode);
 SkXfermode* SkXfermode::Create(Mode mode) {
     SkASSERT(SK_ARRAY_COUNT(gProcCoeffs) == kModeCount);
     SkASSERT(SK_ARRAY_COUNT(gCachedXfermodes) == kModeCount);
     if ((unsigned)mode >= kModeCount) {
         // report error
         return NULL;
     }
     // Skia's "defaut" mode is srcover. NULL in SkPaint is interpreted as srcover
     // so we can just return NULL from the factory.
     if (kSrcOver_Mode == mode) {
         return NULL;
     }
     // guard our access to gCachedXfermodes, since we may write into it
     SkAutoMutexAcquire ac(gCachedXfermodesMutex);
     SkXfermode* xfer = gCachedXfermodes[mode];
     if (NULL == xfer) {
         ProcCoeff rec = gProcCoeffs[mode];
         SkXfermodeProc pp = SkPlatformXfermodeProcFactory(mode);
         if (pp != NULL) {
             rec.fProc = pp;
         }
         // check if we have a platform optim for that
         SkProcCoeffXfermode* xfm = SkPlatformXfermodeFactory(rec, mode);
         if (xfm != NULL) {
             xfer = xfm;
         } else {
             // All modes can in theory be represented by the ProcCoeff rec, since
             // it contains function ptrs. However, a few modes are both simple and
             // commonly used, so we call those out for their own subclasses here.
             switch (mode) {
                 case kClear_Mode:
                     xfer = SkClearXfermode::Create(rec);
                     break;
                 case kSrc_Mode:
                     xfer = SkSrcXfermode::Create(rec);
                     break;
                 case kSrcOver_Mode:
                     SkASSERT(false);    // should not land here
                     break;
                 case kDstIn_Mode:
                     xfer = SkDstInXfermode::Create(rec);
                     break;
                 case kDstOut_Mode:
                     xfer = SkDstOutXfermode::Create(rec);
                     break;
                 default:
                     // no special-case, just rely in the rec and its function-ptrs
                     xfer = SkProcCoeffXfermode::Create(rec, mode);
                     break;
             }
         }
         gCachedXfermodes[mode] = xfer;
     }
     return SkSafeRef(xfer);
 }
 SkXfermodeProc SkXfermode::GetProc(Mode mode) {
     SkXfermodeProc  proc = NULL;
     if ((unsigned)mode < kModeCount) {
         proc = gProcCoeffs[mode].fProc;
     }
     return proc;
 }
 bool SkXfermode::ModeAsCoeff(Mode mode, Coeff* src, Coeff* dst) {
     SkASSERT(SK_ARRAY_COUNT(gProcCoeffs) == kModeCount);
     if ((unsigned)mode >= (unsigned)kModeCount) {
         // illegal mode parameter
         return false;
     }
     const ProcCoeff& rec = gProcCoeffs[mode];
     if (CANNOT_USE_COEFF == rec.fSC) {
         return false;
     }
     SkASSERT(CANNOT_USE_COEFF != rec.fDC);
     if (src) {
         *src = rec.fSC;
     }
     if (dst) {
         *dst = rec.fDC;
     }
     return true;
 }
 bool SkXfermode::AsMode(const SkXfermode* xfer, Mode* mode) {
     if (NULL == xfer) {
         if (mode) {
             *mode = kSrcOver_Mode;
         }
         return true;
     }
     return xfer->asMode(mode);
 }
 bool SkXfermode::AsCoeff(const SkXfermode* xfer, Coeff* src, Coeff* dst) {
     if (NULL == xfer) {
         return ModeAsCoeff(kSrcOver_Mode, src, dst);
     }
     return xfer->asCoeff(src, dst);
 }
 bool SkXfermode::IsMode(const SkXfermode* xfer, Mode mode) {
     // if xfer==null then the mode is srcover
     Mode m = kSrcOver_Mode;
     if (xfer && !xfer->asMode(&m)) {
         return false;
     }
     return mode == m;
 }
 ///////////////////////////////////////////////////////////////////////////////
 //////////// 16bit xfermode procs
 #ifdef SK_DEBUG
 static bool require_255(SkPMColor src) { return SkGetPackedA32(src) == 0xFF; }
 static bool require_0(SkPMColor src) { return SkGetPackedA32(src) == 0; }
 #endif
 static uint16_t src_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     return SkPixel32ToPixel16(src);
 }
 static uint16_t dst_modeproc16(SkPMColor src, uint16_t dst) {
     return dst;
 }
 static uint16_t srcover_modeproc16_0(SkPMColor src, uint16_t dst) {
     SkASSERT(require_0(src));
     return dst;
 }
 static uint16_t srcover_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     return SkPixel32ToPixel16(src);
 }
 static uint16_t dstover_modeproc16_0(SkPMColor src, uint16_t dst) {
     SkASSERT(require_0(src));
     return dst;
 }
 static uint16_t dstover_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     return dst;
 }
 static uint16_t srcin_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     return SkPixel32ToPixel16(src);
 }
 static uint16_t dstin_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     return dst;
 }
 static uint16_t dstout_modeproc16_0(SkPMColor src, uint16_t dst) {
     SkASSERT(require_0(src));
     return dst;
 }
 static uint16_t srcatop_modeproc16(SkPMColor src, uint16_t dst) {
     unsigned isa = 255 - SkGetPackedA32(src);
     return SkPackRGB16(
            SkPacked32ToR16(src) + SkAlphaMulAlpha(SkGetPackedR16(dst), isa),
            SkPacked32ToG16(src) + SkAlphaMulAlpha(SkGetPackedG16(dst), isa),
            SkPacked32ToB16(src) + SkAlphaMulAlpha(SkGetPackedB16(dst), isa));
 }
 static uint16_t srcatop_modeproc16_0(SkPMColor src, uint16_t dst) {
     SkASSERT(require_0(src));
     return dst;
 }
 static uint16_t srcatop_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     return SkPixel32ToPixel16(src);
 }
 static uint16_t dstatop_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     return dst;
 }
 /*********
     darken and lighten boil down to this.
     darken  = (1 - Sa) * Dc + min(Sc, Dc)
     lighten = (1 - Sa) * Dc + max(Sc, Dc)
     if (Sa == 0) these become
         darken  = Dc + min(0, Dc) = 0
         lighten = Dc + max(0, Dc) = Dc
     if (Sa == 1) these become
         darken  = min(Sc, Dc)
         lighten = max(Sc, Dc)
 */
 static uint16_t darken_modeproc16_0(SkPMColor src, uint16_t dst) {
     SkASSERT(require_0(src));
     return 0;
 }
 static uint16_t darken_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     unsigned r = SkFastMin32(SkPacked32ToR16(src), SkGetPackedR16(dst));
     unsigned g = SkFastMin32(SkPacked32ToG16(src), SkGetPackedG16(dst));
     unsigned b = SkFastMin32(SkPacked32ToB16(src), SkGetPackedB16(dst));
     return SkPackRGB16(r, g, b);
 }
 static uint16_t lighten_modeproc16_0(SkPMColor src, uint16_t dst) {
     SkASSERT(require_0(src));
     return dst;
 }
 static uint16_t lighten_modeproc16_255(SkPMColor src, uint16_t dst) {
     SkASSERT(require_255(src));
     unsigned r = SkMax32(SkPacked32ToR16(src), SkGetPackedR16(dst));
     unsigned g = SkMax32(SkPacked32ToG16(src), SkGetPackedG16(dst));
     unsigned b = SkMax32(SkPacked32ToB16(src), SkGetPackedB16(dst));
     return SkPackRGB16(r, g, b);
 }
 struct Proc16Rec {
     SkXfermodeProc16    fProc16_0;
     SkXfermodeProc16    fProc16_255;
     SkXfermodeProc16    fProc16_General;
 };
 static const Proc16Rec gModeProcs16[] = {
     { NULL,                 NULL,                   NULL            }, // CLEAR
     { NULL,                 src_modeproc16_255,     NULL            },
     { dst_modeproc16,       dst_modeproc16,         dst_modeproc16  },
     { srcover_modeproc16_0, srcover_modeproc16_255, NULL            },
     { dstover_modeproc16_0, dstover_modeproc16_255, NULL            },
     { NULL,                 srcin_modeproc16_255,   NULL            },
     { NULL,                 dstin_modeproc16_255,   NULL            },
     { NULL,                 NULL,                   NULL            },// SRC_OUT
     { dstout_modeproc16_0,  NULL,                   NULL            },
     { srcatop_modeproc16_0, srcatop_modeproc16_255, srcatop_modeproc16  },
     { NULL,                 dstatop_modeproc16_255, NULL            },
     { NULL,                 NULL,                   NULL            }, // XOR
     { NULL,                 NULL,                   NULL            }, // plus
     { NULL,                 NULL,                   NULL            }, // modulate
     { NULL,                 NULL,                   NULL            }, // screen
     { NULL,                 NULL,                   NULL            }, // overlay
     { darken_modeproc16_0,  darken_modeproc16_255,  NULL            }, // darken
     { lighten_modeproc16_0, lighten_modeproc16_255, NULL            }, // lighten
     { NULL,                 NULL,                   NULL            }, // colordodge
     { NULL,                 NULL,                   NULL            }, // colorburn
     { NULL,                 NULL,                   NULL            }, // hardlight
     { NULL,                 NULL,                   NULL            }, // softlight
     { NULL,                 NULL,                   NULL            }, // difference
     { NULL,                 NULL,                   NULL            }, // exclusion
     { NULL,                 NULL,                   NULL            }, // multiply
     { NULL,                 NULL,                   NULL            }, // hue
     { NULL,                 NULL,                   NULL            }, // saturation
     { NULL,                 NULL,                   NULL            }, // color
     { NULL,                 NULL,                   NULL            }, // luminosity
 };
 SkXfermodeProc16 SkXfermode::GetProc16(Mode mode, SkColor srcColor) {
     SkXfermodeProc16  proc16 = NULL;
     if ((unsigned)mode < kModeCount) {
         const Proc16Rec& rec = gModeProcs16[mode];
         unsigned a = SkColorGetA(srcColor);
         if (0 == a) {
             proc16 = rec.fProc16_0;
         } else if (255 == a) {
             proc16 = rec.fProc16_255;
         } else {
             proc16 = rec.fProc16_General;
         }
     }
     return proc16;
 }
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkProcCoeffXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkClearXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkSrcXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkDstInXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkDstOutXfermode)
 #if !SK_ARM_NEON_IS_NONE
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkNEONProcCoeffXfermode)
 #endif
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END

The Tor Browser / annotate

gfx/skia/trunk/src/core/SkXfermode.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/core/SkXfermode.cpp