store SkAlphaType inside SkBitmap, on road to support unpremul

src/lazy/SkBitmapFactory.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapFactory.h"
 
 #include "SkBitmap.h"
@@ skipping 43 matching lines @@
     }
 
     bool isOpaque = false;
     SkBitmap::Config config = SkImageInfoToBitmapConfig(info, &isOpaque);
 
     Target target;
     // FIMXE: There will be a problem if this rowbytes is calculated differently from
     // in SkLazyPixelRef.
     target.fRowBytes = SkImageMinRowBytes(info);
 
-    dst->setConfig(config, info.fWidth, info.fHeight, target.fRowBytes);
-    dst->setIsOpaque(isOpaque);
+    dst->setConfig(config, info.fWidth, info.fHeight, target.fRowBytes,
+                   isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType);

[scroggo, 2013/10/18 19:32:40]

info should have the actual alpha type.

 
     // fImageCache and fCacheSelector are mutually exclusive.
     SkASSERT(NULL == fImageCache || NULL == fCacheSelector);
 
     SkImageCache* cache = NULL == fCacheSelector ? fImageCache : fCacheSelector->selectCache(info);
 
     if (cache != NULL) {
         // Now set a new LazyPixelRef on dst.
         SkAutoTUnref<SkLazyPixelRef> lazyRef(SkNEW_ARGS(SkLazyPixelRef,
                                                         (data, fDecodeProc, cache)));
         dst->setPixelRef(lazyRef);
         return true;
     } else {
         dst->allocPixels();
         target.fAddr = dst->getPixels();
         return fDecodeProc(data->data(), data->size(), &info, &target);
     }
 }