Revert of Revert of Extract most of the mutable state of SkShader into a separate Context object.

src/core/SkBitmapProcState.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkBitmapProcState.h"
 #include "SkColorPriv.h"
 #include "SkFilterProc.h"
@@ skipping 342 matching lines @@
                 fScaledBitmap.reset();
                 return false;
             }
         }
     }
     fBitmap = &fScaledBitmap;
     unlocker.release();
     return true;
 }
 
-void SkBitmapProcState::endContext() {
-    SkDELETE(fBitmapFilter);
-    fBitmapFilter = NULL;
-    fScaledBitmap.reset();
-
-    if (fScaledCacheID) {
-        SkScaledImageCache::Unlock(fScaledCacheID);
-        fScaledCacheID = NULL;
-    }
-}
-
 SkBitmapProcState::~SkBitmapProcState() {
     if (fScaledCacheID) {
         SkScaledImageCache::Unlock(fScaledCacheID);
     }
     SkDELETE(fBitmapFilter);
 }
 
 bool SkBitmapProcState::chooseProcs(const SkMatrix& inv, const SkPaint& paint) {
     SkASSERT(fOrigBitmap.width() && fOrigBitmap.height());
 
     fBitmap = NULL;
     fInvMatrix = inv;
     fFilterLevel = paint.getFilterLevel();
 
     SkASSERT(NULL == fScaledCacheID);
 
     // possiblyScaleImage will look to see if it can rescale the image as a
     // preprocess; either by scaling up to the target size, or by selecting
     // a nearby mipmap level.  If it does, it will adjust the working
     // matrix as well as the working bitmap.  It may also adjust the filter
     // quality to avoid re-filtering an already perfectly scaled image.
     if (!this->possiblyScaleImage()) {
         if (!this->lockBaseBitmap()) {
             return false;
         }
     }
     // The above logic should have always assigned fBitmap, but in case it
     // didn't, we check for that now...
+    // TODO(dominikg): Ask humper@ if we can just use an SkASSERT(fBitmap)?
     if (NULL == fBitmap) {
         return false;
     }
 
     // If we are "still" kMedium_FilterLevel, then the request was not fulfilled by possiblyScale,
     // so we downgrade to kLow (so the rest of the sniffing code can assume that)
     if (SkPaint::kMedium_FilterLevel == fFilterLevel) {
         fFilterLevel = SkPaint::kLow_FilterLevel;
     }
 
@@ skipping 68 matching lines @@
         if (fInvType <= SkMatrix::kTranslate_Mask ||
                 !valid_for_filtering(fBitmap->width() | fBitmap->height())) {
             fFilterLevel = SkPaint::kNone_FilterLevel;
         }
     }
 
     // At this point, we know exactly what kind of sampling the per-scanline
     // shader will perform.
 
     fMatrixProc = this->chooseMatrixProc(trivialMatrix);
+    // TODO(dominikg): SkASSERT(fMatrixProc) instead? chooseMatrixProc never returns NULL.
     if (NULL == fMatrixProc) {
         return false;
     }
 
     ///////////////////////////////////////////////////////////////////////
 
     // No need to do this if we're doing HQ sampling; if filter quality is
     // still set to HQ by the time we get here, then we must have installed
     // the shader procs above and can skip all this.
 
@@ skipping 21 matching lines @@
                 index |= 16;
                 break;
             case SkBitmap::kARGB_4444_Config:
                 index |= 24;
                 break;
             case SkBitmap::kA8_Config:
                 index |= 32;
                 fPaintPMColor = SkPreMultiplyColor(paint.getColor());
                 break;
             default:
+                // TODO(dominikg): Should we ever get here? SkASSERT(false) instead?
                 return false;
         }
 
     #if !SK_ARM_NEON_IS_ALWAYS
         static const SampleProc32 gSkBitmapProcStateSample32[] = {
             S32_opaque_D32_nofilter_DXDY,
             S32_alpha_D32_nofilter_DXDY,
             S32_opaque_D32_nofilter_DX,
             S32_alpha_D32_nofilter_DX,
             S32_opaque_D32_filter_DXDY,
@@ skipping 499 matching lines @@
     } else {
         size >>= 2;
     }
 
     if (fFilterLevel != SkPaint::kNone_FilterLevel) {
         size >>= 1;
     }
 
     return size;
 }