Added support for non-separable blending modes and fixed scalar issue

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 81 matching lines @@
         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]
-
-        // all remaining modes are defined in the SVG Compositing standard
-        // http://www.w3.org/TR/2009/WD-SVGCompositing-20090430/
-        kPlus_Mode,
+        kPlus_Mode,     //!< [Sa + Da, Sc + Dc]
         kModulate_Mode, // multiplies all components (= alpha and color)
 
         // all above modes can be expressed as pair of src/dst Coeffs
         kCoeffModesCnt,
 
+        // Following blend modes are defined in the CSS Compositing standard: 
+        // https://dvcs.w3.org/hg/FXTF/rawfile/tip/compositing/index.html#blending
         kScreen_Mode = kCoeffModesCnt,
         kOverlay_Mode,
         kDarken_Mode,
         kLighten_Mode,
         kColorDodge_Mode,
         kColorBurn_Mode,
         kHardLight_Mode,
         kSoftLight_Mode,
         kDifference_Mode,
         kExclusion_Mode,
         kMultiply_Mode,
 
-        kLastMode = kMultiply_Mode
+        kHue_Mode,
+        kSaturation_Mode,
+        kColor_Mode,
+        kLuminosity_Mode,
+
+        kLastMode = kLuminosity_Mode
     };
 
     /**
      *  If the xfermode is one of the modes in the Mode enum, then asMode()
      *  returns true and sets (if not null) mode accordingly. Otherwise it
      *  returns false and ignores the mode parameter.
      */
     virtual bool asMode(Mode* mode) const;
 
     /**
@@ skipping 98 matching lines @@
         fProc = proc;
     }
 
 private:
     SkXfermodeProc  fProc;
 
     typedef SkXfermode INHERITED;
 };
 
 #endif