Add flag to gradients to interpolate colors in premul space. Experimental API to encapsulate the sh…

src/effects/gradients/SkGradientShaderPriv.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkGradientShaderPriv_DEFINED
 #define SkGradientShaderPriv_DEFINED
 
@@ skipping 75 matching lines @@
         Descriptor() {
             sk_bzero(this, sizeof(*this));
             fTileMode = SkShader::kClamp_TileMode;
         }
 
         const SkColor*      fColors;
         const SkScalar*     fPos;
         int                 fCount;
         SkShader::TileMode  fTileMode;
         SkUnitMapper*       fMapper;
+        uint32_t            fFlags;
     };
 
 public:
     SkGradientShaderBase(const Descriptor& desc);
     virtual ~SkGradientShaderBase();
 
     virtual bool setContext(const SkBitmap&, const SkPaint&, const SkMatrix&) SK_OVERRIDE;
     virtual uint32_t getFlags() SK_OVERRIDE { return fFlags; }
     virtual bool isOpaque() const SK_OVERRIDE;
 
@@ skipping 28 matching lines @@
 
     SkUnitMapper* fMapper;
     SkMatrix    fPtsToUnit;     // set by subclass
     SkMatrix    fDstToIndex;
     SkMatrix::MapXYProc fDstToIndexProc;
     TileMode    fTileMode;
     TileProc    fTileProc;
     int         fColorCount;
     uint8_t     fDstToIndexClass;
     uint8_t     fFlags;
+    uint8_t     fGradFlags;
 
     struct Rec {
         SkFixed     fPos;   // 0...1
         uint32_t    fScale; // (1 << 24) / range
     };
     Rec*        fRecs;
 
     const uint16_t*     getCache16() const;
     const SkPMColor*    getCache32() const;
 
@@ skipping 11 matching lines @@
 
     mutable uint16_t*   fCache16;   // working ptr. If this is NULL, we need to recompute the cache values
     mutable SkPMColor*  fCache32;   // working ptr. If this is NULL, we need to recompute the cache values
 
     mutable uint16_t*   fCache16Storage;    // storage for fCache16, allocated on demand
     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 void Build16bitCache(uint16_t[], SkColor c0, SkColor c1, int count);
     static void Build32bitCache(SkPMColor[], SkColor c0, SkColor c1, int count,
-                                U8CPU alpha);
+                                U8CPU alpha, uint32_t gradFlags);
     void setCacheAlpha(U8CPU alpha) const;
     void initCommon();
 
     typedef SkShader INHERITED;
 };
 
 static inline int init_dither_toggle(int x, int y) {
     x &= 1;
     y = (y & 1) << 1;
     return (x | y) * SkGradientShaderBase::kDitherStride32;
@@ skipping 152 matching lines @@
     SkScalar fCachedYCoord;
     GrGLUniformManager::UniformHandle fFSYUni;
     GrGLEffectMatrix fEffectMatrix;
 
     typedef GrGLEffect INHERITED;
 };
 
 #endif
 
 #endif