add installPixels

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 230 matching lines @@
         any pixel/colortable ownership, just like reset().
     */
     bool setConfig(Config, int width, int height, size_t rowBytes, SkAlphaType);
 
     bool setConfig(Config config, int width, int height, size_t rowBytes = 0) {
         return this->setConfig(config, width, height, rowBytes,
                                kPremul_SkAlphaType);
     }
 
     bool setConfig(const SkImageInfo& info, size_t rowBytes = 0);
-
+    
+    /**
+     *  Allocate a pixelref to match the specified image info, using the default
+     *  allocator, computing a minimum rowBytes based on info.
+     *  On failure, the bitmap will be set to empty and return false.
+     */
+    bool allocPixels(const SkImageInfo&, SkColorTable* ctable = NULL);

[scroggo, 2014/01/23 21:53:02]

I assume these are to replace the existing setConfig + allocPixels. Does it make
sense to continue to allow the caller to specify how the pixels are allocated?
Or will they just then be forced to call installPixels?

Currently, Android passes an SkBitmap::Allocator to the image decoders. Their
special Allocator provides a Java allocation of memory that they can reuse for
future bitmaps. How can we continue to support this pattern? Perhaps their
Allocator can call installPixels?

[hal.canary, 2014/01/23 22:05:24]

Why not:

    bool allocPixels(const SkImageInfo&, 
                     Allocator*,
                     SkColorTable*);

[reed1, 2014/01/24 14:54:48]

Done.

+    
+    /**
+     *  Install a pixelref that wraps the specified pixels and rowBytes, and
+     *  optional ReleaseProc and context. When the pixels are no longer
+     *  referenced, if ReleaseProc is not null, it will be called with the
+     *  pixels and context as parameters.
+     *  On failure, the bitmap will be set to empty and return false.
+     */
+    bool installPixels(const SkImageInfo&, void* pixels, size_t rowBytes,
+                       void (*ReleaseProc)(void* addr, void* context),
+                       void* context);
+    
     /**
      *  If the bitmap's config can be represented as SkImageInfo, return true,
      *  and if info is not-null, set it to the bitmap's info. If it cannot be
      *  represented as SkImageInfo, return false and ignore the info parameter.
      */
     bool asImageInfo(SkImageInfo* info) const;
 
     /** Use this to assign a new pixel address for an existing bitmap. This
         will automatically release any pixelref previously installed. Only call
         this if you are handling ownership/lifetime of the pixel memory.
@@ skipping 565 matching lines @@
 
 inline SkPMColor SkBitmap::getIndex8Color(int x, int y) const {
     SkASSERT(fPixels);
     SkASSERT(fConfig == kIndex8_Config);
     SkASSERT((unsigned)x < fWidth && (unsigned)y < fHeight);
     SkASSERT(fColorTable);
     return (*fColorTable)[*((const uint8_t*)fPixels + y * fRowBytes + x)];
 }
 
 #endif