Revert "Revert "speed up A8 by creating a new entry-point in SkDraw that blits the path's coverage …

src/core/SkBlitter.cpp

 
 /*
  * 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.
  */
 
 
 #include "SkBlitter.h"
@@ skipping 832 matching lines @@
             default:
                 break;
         }
     }
     return kNormal_XferInterp;
 }
 
 SkBlitter* SkBlitter::Choose(const SkBitmap& device,
                              const SkMatrix& matrix,
                              const SkPaint& origPaint,
-                             void* storage, size_t storageSize) {
+                             void* storage, size_t storageSize,
+                             bool drawCoverage) {
     SkASSERT(storageSize == 0 || storage != NULL);
 
     SkBlitter*  blitter = NULL;
 
     // which check, in case we're being called by a client with a dummy device
     // (e.g. they have a bounder that always aborts the draw)
-    if (SkBitmap::kNo_Config == device.config()) {
+    if (SkBitmap::kNo_Config == device.config() ||
+            (drawCoverage && (SkBitmap::kA8_Config != device.config()))) {
         SK_PLACEMENT_NEW(blitter, SkNullBlitter, storage, storageSize);
         return blitter;
     }
 
     SkShader* shader = origPaint.getShader();
     SkColorFilter* cf = origPaint.getColorFilter();
     SkXfermode* mode = origPaint.getXfermode();
     Sk3DShader* shader3D = NULL;
 
     SkTCopyOnFirstWrite<SkPaint> paint(origPaint);
@@ skipping 62 matching lines @@
      *      endContext
      *  We make the first call here, in case it fails we can abort the draw.
      *  The endContext() call is made by the blitter (assuming setContext did
      *  not fail) in its destructor.
      */
     if (shader && !shader->setContext(device, *paint, matrix)) {
         SK_PLACEMENT_NEW(blitter, SkNullBlitter, storage, storageSize);
         return blitter;
     }
 
+    
     switch (device.config()) {
         case SkBitmap::kA1_Config:
             SK_PLACEMENT_NEW_ARGS(blitter, SkA1_Blitter,
                                   storage, storageSize, (device, *paint));
             break;
 
         case SkBitmap::kA8_Config:
-            if (shader) {
+            if (drawCoverage) {
+                SkASSERT(NULL == shader);
+                SkASSERT(NULL == paint->getXfermode());
+                SK_PLACEMENT_NEW_ARGS(blitter, SkA8_Coverage_Blitter,
+                                      storage, storageSize, (device, *paint));
+            } else if (shader) {
                 SK_PLACEMENT_NEW_ARGS(blitter, SkA8_Shader_Blitter,
                                       storage, storageSize, (device, *paint));
             } else {
                 SK_PLACEMENT_NEW_ARGS(blitter, SkA8_Blitter,
                                       storage, storageSize, (device, *paint));
             }
             break;
 
         case SkBitmap::kRGB_565_Config:
             blitter = SkBlitter_ChooseD565(device, *paint, storage, storageSize);
@@ skipping 46 matching lines @@
 
     fShader->ref();
     fShaderFlags = fShader->getFlags();
 }
 
 SkShaderBlitter::~SkShaderBlitter() {
     SkASSERT(fShader->setContextHasBeenCalled());
     fShader->endContext();
     fShader->unref();
 }