Image filters: refactor input GPU processing into filterInputGPU().

include/core/SkImageFilter.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageFilter_DEFINED
 #define SkImageFilter_DEFINED
 
@@ skipping 230 matching lines @@
     static SkImageFilter* CreateMatrixFilter(const SkMatrix& matrix,
                                              SkFilterQuality,
                                              SkImageFilter* input = NULL);
 
 #if SK_SUPPORT_GPU
     /**
      * Wrap the given texture in a texture-backed SkBitmap.
      */
     static void WrapTexture(GrTexture* texture, int width, int height, SkBitmap* result);
 
-    /**
-     * Recursively evaluate this filter on the GPU. If the filter has no GPU
-     * implementation, it will be processed in software and uploaded to the GPU.
-     */
-    bool getInputResultGPU(SkImageFilter::Proxy* proxy, const SkBitmap& src, const Context&,
-                           SkBitmap* result, SkIPoint* offset) const;
+    // Helper function which invokes GPU filter processing on the
+    // input at the specified "index". If the input is null, it leaves
+    // "result" and "offset" untouched, and returns true. If the input
+    // has a GPU implementation, it will be invoked directly.
+    // Otherwise, the filter will be processed in software and
+    // uploaded to the GPU.
+    bool filterInputGPU(int index, SkImageFilter::Proxy* proxy, const SkBitmap& src, const Context&,
+                        SkBitmap* result, SkIPoint* offset) const;
 #endif
 
     SK_TO_STRING_PUREVIRT()
     SK_DEFINE_FLATTENABLE_TYPE(SkImageFilter)
 
 protected:
     class Common {
     public:
         Common() {}
         ~Common();
@@ skipping 151 matching lines @@
  */
 #define SK_IMAGEFILTER_UNFLATTEN_COMMON(localVar, expectedCount)    \
     Common localVar;                                                \
     do {                                                            \
         if (!localVar.unflatten(buffer, expectedCount)) {           \
             return NULL;                                            \
         }                                                           \
     } while (0)
 
 #endif