Handling large jpegs in CPU raster - downsample to display res and 565

src/image/SkImage_Base.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 SkImage_Base_DEFINED
 #define SkImage_Base_DEFINED
 
@@ skipping 16 matching lines @@
 
     virtual const void* onPeekPixels(SkImageInfo*, size_t* /*rowBytes*/) const { return nullptr; }
 
     // Default impl calls onDraw
     virtual bool onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
                               int srcX, int srcY) const;
 
     virtual GrTexture* peekTexture() const { return nullptr; }
 
     // return a read-only copy of the pixels. We promise to not modify them,
-    // but only inspect them (or encode them).
-    virtual bool getROPixels(SkBitmap*) const = 0;
+    // but only inspect them (or encode them). scaleHint (0 < defines lowest
+    // acceptable (meaning smaller won't be provided) scale for requested bitmap.
+    virtual bool getROPixels(SkBitmap*, SkScalar scaleHint = SK_Scalar1) const = 0;
 
     virtual SkImage* onApplyFilter(SkImageFilter*, SkIPoint* offset,
                                    bool forceResultToOriginalSize) const;
 
     virtual SkSurface* onNewSurface(const SkImageInfo& info) const {
         return SkSurface::NewRaster(info);
     }
 
     // Caller must call unref when they are done.
     virtual GrTexture* asTextureRef(GrContext*, const GrTextureParams&) const = 0;
@@ skipping 21 matching lines @@
 
 static inline SkImage_Base* as_IB(SkImage* image) {
     return static_cast<SkImage_Base*>(image);
 }
 
 static inline const SkImage_Base* as_IB(const SkImage* image) {
     return static_cast<const SkImage_Base*>(image);
 }
 
 #endif