create struct to hold all the params passed around for shader::context

src/effects/gradients/SkRadialGradient.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 SkRadialGradient_DEFINED
 #define SkRadialGradient_DEFINED
 
 #include "SkGradientShaderPriv.h"
 
 class SkRadialGradient : public SkGradientShaderBase {
 public:
     SkRadialGradient(const SkPoint& center, SkScalar radius, const Descriptor&,
                      const SkMatrix* localMatrix);
 
-    virtual SkShader::Context* createContext(const SkBitmap&, const SkPaint&, const SkMatrix&,
-                                             void* storage) const SK_OVERRIDE;
+    virtual SkShader::Context* createContext(const ContextRec&, void* storage) const SK_OVERRIDE;
     virtual size_t contextSize() const SK_OVERRIDE;
 
     class RadialGradientContext : public SkGradientShaderBase::GradientShaderBaseContext {
     public:
-        RadialGradientContext(const SkRadialGradient& shader, const SkBitmap& device,
-                              const SkPaint& paint, const SkMatrix& matrix);
-        ~RadialGradientContext() {}
+        RadialGradientContext(const SkRadialGradient&, const ContextRec&);
 
         virtual void shadeSpan(int x, int y, SkPMColor dstC[], int count) SK_OVERRIDE;
         virtual void shadeSpan16(int x, int y, uint16_t dstC[], int count) SK_OVERRIDE;
 
     private:
         typedef SkGradientShaderBase::GradientShaderBaseContext INHERITED;
     };
 
     virtual BitmapType asABitmap(SkBitmap* bitmap,
                                  SkMatrix* matrix,
                                  TileMode* xy) const SK_OVERRIDE;
     virtual GradientType asAGradient(GradientInfo* info) const SK_OVERRIDE;
     virtual GrEffectRef* asNewEffect(GrContext* context, const SkPaint&) const SK_OVERRIDE;
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkRadialGradient)
 
 protected:
     SkRadialGradient(SkReadBuffer& buffer);
     virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE;
 
 private:
     typedef SkGradientShaderBase INHERITED;
     const SkPoint fCenter;
     const SkScalar fRadius;
 };
 
 #endif