Add all remaining separable xfer modes to GPU backend.

include/core/SkXfermode.h

 
 /*
  * 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.
  */
 
 
 #ifndef SkXfermode_DEFINED
@@ skipping 69 matching lines @@
      */
     static bool AsCoeff(const SkXfermode*, Coeff* src, Coeff* dst);
 
     /** List of predefined xfermodes.
         The algebra for the modes uses the following symbols:
         Sa, Sc  - source alpha and color
         Da, Dc - destination alpha and color (before compositing)
         [a, c] - Resulting (alpha, color) values
         For these equations, the colors are in premultiplied state.
         If no xfermode is specified, kSrcOver is assumed.
+        The modes are ordered by those that can be expressed as a pair of Coeffs, followed by those
+        that aren't Coeffs but have separable r,g,b computations, and finally
+        those that are not separable.
      */
     enum Mode {
         kClear_Mode,    //!< [0, 0]
         kSrc_Mode,      //!< [Sa, Sc]
         kDst_Mode,      //!< [Da, Dc]
         kSrcOver_Mode,  //!< [Sa + Da - Sa*Da, Rc = Sc + (1 - Sa)*Dc]
         kDstOver_Mode,  //!< [Sa + Da - Sa*Da, Rc = Dc + (1 - Da)*Sc]
         kSrcIn_Mode,    //!< [Sa * Da, Sc * Da]
         kDstIn_Mode,    //!< [Sa * Da, Sa * Dc]
         kSrcOut_Mode,   //!< [Sa * (1 - Da), Sc * (1 - Da)]
         kDstOut_Mode,   //!< [Da * (1 - Sa), Dc * (1 - Sa)]
         kSrcATop_Mode,  //!< [Da, Sc * Da + (1 - Sa) * Dc]
         kDstATop_Mode,  //!< [Sa, Sa * Dc + Sc * (1 - Da)]
         kXor_Mode,      //!< [Sa + Da - 2 * Sa * Da, Sc * (1 - Da) + (1 - Sa) * Dc]
         kPlus_Mode,     //!< [Sa + Da, Sc + Dc]
         kModulate_Mode, // multiplies all components (= alpha and color)
 
         // Following blend modes are defined in the CSS Compositing standard:
         // https://dvcs.w3.org/hg/FXTF/rawfile/tip/compositing/index.html#blending
         kScreen_Mode,
-        // all above modes can be expressed as pair of src/dst Coeffs
-        kCoeffModesCnt,
-        kOverlay_Mode = kCoeffModesCnt,
+        kLastCoeffMode = kScreen_Mode,
+
+        kOverlay_Mode,
         kDarken_Mode,
         kLighten_Mode,
         kColorDodge_Mode,
         kColorBurn_Mode,
         kHardLight_Mode,
         kSoftLight_Mode,
         kDifference_Mode,
         kExclusion_Mode,
         kMultiply_Mode,
+        kLastSeparableMode = kMultiply_Mode,
 
         kHue_Mode,
         kSaturation_Mode,
         kColor_Mode,
         kLuminosity_Mode,
-
         kLastMode = kLuminosity_Mode
     };
 
     /**
      * Gets the name of the Mode as a string.
      */
     static const char* ModeName(Mode);
 
     /**
      *  If the xfermode is one of the modes in the Mode enum, then asMode()
@@ skipping 128 matching lines @@
         fProc = proc;
     }
 
 private:
     SkXfermodeProc  fProc;
 
     typedef SkXfermode INHERITED;
 };
 
 #endif