use pixmaps for dst in sprites -- NO BITMAPS

include/core/SkBitmap.h

 /*
  * Copyright 2006 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 SkBitmap_DEFINED
 #define SkBitmap_DEFINED
 
@@ skipping 636 matching lines @@
         @param allocator Allocator used to allocate the pixelref for the dst
                          bitmap. If this is null, the standard HeapAllocator
                          will be used.
         @param offset If not null, it is set to top-left coordinate to position
                       the returned bitmap so that it visually lines up with the
                       original
     */
     bool extractAlpha(SkBitmap* dst, const SkPaint* paint, Allocator* allocator,
                       SkIPoint* offset) const;
 
+    /**
+     *  If the pixels are available from this bitmap (w/o locking) return true, and fill out the
+     *  specified pixmap (if not null). If the pixels are not available (either because there are
+     *  none, or becuase accessing them would require locking or other machinary) return false and
+     *  ignore the pixmap parameter.
+     *
+     *  Note: if this returns true, the results (in the pixmap) are only valid until the bitmap
+     *  is changed in anyway, in which case the results are invalid.
+     */
+    bool peekPixels(SkPixmap*) const;
+
     SkDEBUGCODE(void validate() const;)
 
     class Allocator : public SkRefCnt {
     public:
         SK_DECLARE_INST_COUNT(Allocator)
 
         /** Allocate the pixel memory for the bitmap, given its dimensions and
             colortype. Return true on success, where success means either setPixels
             or setPixelRef was called. The pixels need not be locked when this
             returns. If the colortype requires a colortable, it also must be
@@ skipping 125 matching lines @@
 
 inline SkPMColor SkBitmap::getIndex8Color(int x, int y) const {
     SkASSERT(fPixels);
     SkASSERT(kIndex_8_SkColorType == this->colorType());
     SkASSERT((unsigned)x < (unsigned)this->width() && (unsigned)y < (unsigned)this->height());
     SkASSERT(fColorTable);
     return (*fColorTable)[*((const uint8_t*)fPixels + y * fRowBytes + x)];
 }
 
 #endif