Skia side RGB to YUV gpu conversion

include/core/SkPixelRef.h

 /*
  * Copyright 2008 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 SkPixelRef_DEFINED
 #define SkPixelRef_DEFINED
 
 #include "SkBitmap.h"
 #include "SkDynamicAnnotations.h"
 #include "SkRefCnt.h"
 #include "SkString.h"
 #include "SkFlattenable.h"
 #include "SkImageInfo.h"
+#include "SkSize.h"
 #include "SkTDArray.h"
 
 //#define xed
 
 #ifdef SK_DEBUG
     /**
      *  Defining SK_IGNORE_PIXELREF_SETPRELOCKED will force all pixelref
      *  subclasses to correctly handle lock/unlock pixels. For performance
      *  reasons, simple malloc-based subclasses call setPreLocked() to skip
      *  the overhead of implementing these calls.
@@ skipping 193 matching lines @@
      */
     bool decodeInto(int pow2, SkBitmap* bitmap) {
         SkASSERT(pow2 >= 0);
         return this->onDecodeInto(pow2, bitmap);
     }
 
     /** Are we really wrapping a texture instead of a bitmap?
      */
     virtual GrTexture* getTexture() { return NULL; }
 
+    /**
+     *  If any planes or rowBytes is NULL, this should output the sizes and return true
+     *  if it can efficiently return YUV planar data. If it cannot, it should return false.
+     *
+     *  If all planes and rowBytes are not NULL, then it should copy the associated Y,U,V data
+     *  into those planes of memory supplied by the caller. It should validate that the sizes
+     *  match what it expected. If the sizes do not match, it should return false.
+     */
+    virtual bool getYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3]) {

[scroggo, 2014/07/21 14:53:00]

Why not follow the convention used in SkImageGenerator (and elsewhere in Skia)
and have

bool getYUV8Planes() {
  return this->onGetYUV8Planes();
}

virtual bool onGetYUV8Planes();

[sugoi1, 2014/07/21 15:08:14]

Done.

+        return false;
+    }
+
     bool readPixels(SkBitmap* dst, const SkIRect* subset = NULL);
 
     /**
      *  Makes a deep copy of this PixelRef, respecting the requested config.
      *  @param colorType Desired colortype.
      *  @param subset Subset of this PixelRef to copy. Must be fully contained within the bounds of
      *         of this PixelRef.
      *  @return A new SkPixelRef, or NULL if either there is an error (e.g. the destination could
      *          not be created with the given config), or this PixelRef does not support deep
      *          copies.
@@ skipping 144 matching lines @@
     /**
      *  Allocate a new pixelref matching the specified ImageInfo, allocating
      *  the memory for the pixels. If the ImageInfo requires a ColorTable,
      *  the pixelref will ref() the colortable.
      *  On failure return NULL.
      */
     virtual SkPixelRef* create(const SkImageInfo&, size_t rowBytes, SkColorTable*) = 0;
 };
 
 #endif