store SkAlphaType inside SkBitmap, on road to support unpremul

src/image/SkSurface_Raster.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 "SkSurface_Base.h"
 #include "SkImagePriv.h"
 #include "SkCanvas.h"
@@ skipping 21 matching lines @@
     bool        fWeOwnThePixels;
 
     typedef SkSurface_Base INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 bool SkSurface_Raster::Valid(const SkImage::Info& info, size_t rowBytes) {
     static const size_t kMaxTotalSize = SK_MaxS32;
 
-    bool isOpaque;
-    SkBitmap::Config config = SkImageInfoToBitmapConfig(info, &isOpaque);
+    SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
 
     int shift = 0;
     switch (config) {
         case SkBitmap::kA8_Config:
             shift = 0;
             break;
         case SkBitmap::kRGB_565_Config:
             shift = 1;
             break;
         case SkBitmap::kARGB_8888_Config:
@@ skipping 22 matching lines @@
     uint64_t size = (uint64_t)info.fHeight * rowBytes;
     if (size > kMaxTotalSize) {
         return false;
     }
 
     return true;
 }
 
 SkSurface_Raster::SkSurface_Raster(const SkImage::Info& info, void* pixels, size_t rb)
         : INHERITED(info.fWidth, info.fHeight) {
-    bool isOpaque;
-    SkBitmap::Config config = SkImageInfoToBitmapConfig(info, &isOpaque);
-
-    fBitmap.setConfig(config, info.fWidth, info.fHeight, rb);
+    SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
+    fBitmap.setConfig(config, info.fWidth, info.fHeight, rb, info.fAlphaType);
     fBitmap.setPixels(pixels);
-    fBitmap.setIsOpaque(isOpaque);
     fWeOwnThePixels = false;    // We are "Direct"
 }
 
 SkSurface_Raster::SkSurface_Raster(const SkImage::Info& info, SkPixelRef* pr, size_t rb)
         : INHERITED(info.fWidth, info.fHeight) {
-    bool isOpaque;
-    SkBitmap::Config config = SkImageInfoToBitmapConfig(info, &isOpaque);
-
-    fBitmap.setConfig(config, info.fWidth, info.fHeight, rb);
+    SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
+    fBitmap.setConfig(config, info.fWidth, info.fHeight, rb, info.fAlphaType);
     fBitmap.setPixelRef(pr);
-    fBitmap.setIsOpaque(isOpaque);
     fWeOwnThePixels = true;
 
-    if (!isOpaque) {
+    if (!SkAlphaTypeIsOpaque(info.fAlphaType)) {
         fBitmap.eraseColor(SK_ColorTRANSPARENT);
     }
 }
 
 SkCanvas* SkSurface_Raster::onNewCanvas() {
     return SkNEW_ARGS(SkCanvas, (fBitmap));
 }
 
 SkSurface* SkSurface_Raster::onNewSurface(const SkImage::Info& info) {
     return SkSurface::NewRaster(info);
@@ skipping 55 matching lines @@
 
     size_t size = (size_t)size64;
     void* pixels = sk_malloc_throw(size);
     if (NULL == pixels) {
         return NULL;
     }
 
     SkAutoTUnref<SkPixelRef> pr(SkNEW_ARGS(SkMallocPixelRef, (pixels, size, NULL, true)));
     return SkNEW_ARGS(SkSurface_Raster, (info, pr, rowBytes));
 }