scaling API on SkPixmap

include/core/SkPixmap.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPixmap_DEFINED
 #define SkPixmap_DEFINED
 
 #include "SkColor.h"
+#include "SkFilterQuality.h"
 #include "SkImageInfo.h"
 
 class SkColorTable;
 struct SkMask;
 
 /**
  *  Pairs SkImageInfo with actual pixels and rowbytes. This class does not try to manage the
  *  lifetime of the pixel memory (nor the colortable if provided).
  */
 class SK_API SkPixmap {
@@ skipping 106 matching lines @@
         return this->readPixels(dstInfo, dstPixels, dstRowBytes, 0, 0);
     }
     bool readPixels(const SkPixmap& dst, int srcX, int srcY) const {
         return this->readPixels(dst.info(), dst.writable_addr(), dst.rowBytes(), srcX, srcY);
     }
     bool readPixels(const SkPixmap& dst) const {
         return this->readPixels(dst.info(), dst.writable_addr(), dst.rowBytes(), 0, 0);
     }
 
     /**
+     *  Copy the pixels from this pixmap into the dst pixmap, converting as needed into dst's
+     *  colortype/alphatype. If the conversion cannot be performed, false is returned.
+     *
+     *  If dst's dimensions differ from the src dimension, the image will be scaled, applying the
+     *  specified filter-quality.
+     */
+    bool scalePixels(const SkPixmap& dst, SkFilterQuality) const;
+
+    /**
      *  Returns true if pixels were written to (e.g. if colorType is kUnknown_SkColorType, this
      *  will return false). If subset does not intersect the bounds of this pixmap, returns false.
      */
     bool erase(SkColor, const SkIRect& subset) const;
 
     bool erase(SkColor color) const { return this->erase(color, this->bounds()); }
 
 private:
     const void*     fPixels;
     SkColorTable*   fCTable;
@@ skipping 98 matching lines @@
 private:
     void        (*fUnlockProc)(void*);
     void*       fUnlockContext;
     SkPixmap    fPixmap;
     bool        fIsLocked;
 
     friend class SkBitmap;
 };
 
 #endif