SkGpuDevice: Delay locking bitmap pixels until we have a known texture cache miss.

src/gpu/SkGr.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 
 #include "SkGr.h"
 
 /*  Fill out buffer with the compressed format Ganesh expects from a colortable
  based bitmap. [palette (colortable) + indices].
 
  At the moment Ganesh only supports 8bit version. If Ganesh allowed we others
  we could detect that the colortable.count is <= 16, and then repack the
  indices as nibbles to save RAM, but it would take more time (i.e. a lot
  slower than memcpy), so skipping that for now.
 
  Ganesh wants a full 256 palette entry, even though Skia's ctable is only as big
  as the colortable.count says it is.
  */
 static void build_compressed_data(void* buffer, const SkBitmap& bitmap) {
     SkASSERT(SkBitmap::kIndex8_Config == bitmap.config());
 
-    SkAutoLockPixels apl(bitmap);
+    SkAutoLockPixels alp(bitmap);
     if (!bitmap.readyToDraw()) {
         SkDEBUGFAIL("bitmap not ready to draw!");
         return;
     }
 
     SkColorTable* ctable = bitmap.getColorTable();
     char* dst = (char*)buffer;
 
     memcpy(dst, ctable->lockColors(), ctable->count() * sizeof(SkPMColor));
     ctable->unlockColors(false);
@@ skipping 90 matching lines @@
                 return result;
             }
         } else {
             origBitmap.copyTo(&tmpBitmap, SkBitmap::kARGB_8888_Config);
             // now bitmap points to our temp, which has been promoted to 32bits
             bitmap = &tmpBitmap;
             desc.fConfig = SkBitmapConfig2GrPixelConfig(bitmap->config());
         }
     }
 
+    SkAutoLockPixels alp(*bitmap);
+    if (!bitmap->readyToDraw()) {
+        return NULL;
+    }
     if (cache) {
         // This texture is likely to be used again so leave it in the cache
         GrCacheID cacheID;
         generate_bitmap_cache_id(origBitmap, &cacheID);
         return ctx->createTexture(params, desc, cacheID, bitmap->getPixels(), bitmap->rowBytes());
     } else {
         // This texture is unlikely to be used again (in its present form) so
         // just use a scratch texture. This will remove the texture from the
         // cache so no one else can find it. Additionally, once unlocked, the
         // scratch texture will go to the end of the list for purging so will
@@ skipping 66 matching lines @@
             return kRGB_565_GrPixelConfig;
         case SkBitmap::kARGB_4444_Config:
             return kRGBA_4444_GrPixelConfig;
         case SkBitmap::kARGB_8888_Config:
             return kSkia8888_GrPixelConfig;
         default:
             // kNo_Config, kA1_Config missing, and kRLE_Index8_Config
             return kUnknown_GrPixelConfig;
     }
 }