[WIP] Add Context to SkDrawLooper.

src/effects/SkBlurDrawLooper.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 "SkBlurDrawLooper.h"
 #include "SkBlurMask.h"     // just for SkBlurMask::ConvertRadiusToSigma
 #include "SkBlurMaskFilter.h"
 #include "SkCanvas.h"
 #include "SkColorFilter.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMaskFilter.h"
 #include "SkPaint.h"
 #include "SkString.h"
 #include "SkStringUtils.h"
+#include "SkTemplatesPriv.h"
 
 SkBlurDrawLooper::SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy,
                                    SkColor color, uint32_t flags) {
     this->init(SkBlurMask::ConvertRadiusToSigma(radius), dx, dy, color, flags);
 }
 
 SkBlurDrawLooper::SkBlurDrawLooper(SkColor color, SkScalar sigma,
                                    SkScalar dx, SkScalar dy, uint32_t flags) {
     this->init(sigma, dx, dy, color, flags);
 }
 
 void SkBlurDrawLooper::init(SkScalar sigma, SkScalar dx, SkScalar dy,
                             SkColor color, uint32_t flags) {
     fDx = dx;
     fDy = dy;
     fBlurColor = color;
     fBlurFlags = flags;
-    fState = kDone;
 
     SkASSERT(flags <= kAll_BlurFlag);
     if (sigma > 0) {
         uint32_t blurFlags = flags & kIgnoreTransform_BlurFlag ?
             SkBlurMaskFilter::kIgnoreTransform_BlurFlag :
             SkBlurMaskFilter::kNone_BlurFlag;
 
         blurFlags |= flags & kHighQuality_BlurFlag ?
             SkBlurMaskFilter::kHighQuality_BlurFlag :
             SkBlurMaskFilter::kNone_BlurFlag;
@@ skipping 36 matching lines @@
 void SkBlurDrawLooper::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fDx);
     buffer.writeScalar(fDy);
     buffer.writeColor(fBlurColor);
     buffer.writeFlattenable(fBlur);
     buffer.writeFlattenable(fColorFilter);
     buffer.writeUInt(fBlurFlags);
 }
 
-void SkBlurDrawLooper::init(SkCanvas*) {
-    fState = kBeforeEdge;
+SkDrawLooper::DrawContext* SkBlurDrawLooper::init(SkCanvas*, void* storage,
+                                                  size_t storageSize) const {
+    BlurDrawLooperContext* context;
+    SK_PLACEMENT_NEW_ARGS(context, BlurDrawLooperContext, storage,
+                          storageSize, (this));

[Dominik Grewe, 2014/02/07 11:57:15]

This actually doesn't check if storageSize is large enough. It simply checks if
it's not 0. I used it nonetheless because it's being used in similar situations
in the code.

+    return context;
 }
 
-bool SkBlurDrawLooper::next(SkCanvas* canvas, SkPaint* paint) {
+SkBlurDrawLooper::BlurDrawLooperContext::BlurDrawLooperContext(
+        const SkBlurDrawLooper* looper)
+    : fLooper(looper), fState(SkBlurDrawLooper::kBeforeEdge) {}
+
+bool SkBlurDrawLooper::BlurDrawLooperContext::next(SkCanvas* canvas,
+                                                   SkPaint* paint) {
     switch (fState) {
         case kBeforeEdge:
             // we do nothing if a maskfilter is already installed
             if (paint->getMaskFilter()) {
                 fState = kDone;
                 return false;
             }
 #ifdef SK_BUILD_FOR_ANDROID
             SkColor blurColor;
-            blurColor = fBlurColor;
+            blurColor = fLooper->fBlurColor;
             if (SkColorGetA(blurColor) == 255) {
                 blurColor = SkColorSetA(blurColor, paint->getAlpha());
             }
             paint->setColor(blurColor);
 #else
-            paint->setColor(fBlurColor);
+            paint->setColor(fLooper->fBlurColor);
 #endif
-            paint->setMaskFilter(fBlur);
-            paint->setColorFilter(fColorFilter);
+            paint->setMaskFilter(fLooper->fBlur);
+            paint->setColorFilter(fLooper->fColorFilter);
             canvas->save(SkCanvas::kMatrix_SaveFlag);
-            if (fBlurFlags & kIgnoreTransform_BlurFlag) {
+            if (fLooper->fBlurFlags & kIgnoreTransform_BlurFlag) {
                 SkMatrix transform(canvas->getTotalMatrix());
-                transform.postTranslate(fDx, fDy);
+                transform.postTranslate(fLooper->fDx, fLooper->fDy);
                 canvas->setMatrix(transform);
             } else {
-                canvas->translate(fDx, fDy);
+                canvas->translate(fLooper->fDx, fLooper->fDy);
             }
             fState = kAfterEdge;
             return true;
         case kAfterEdge:
             canvas->restore();
             fState = kDone;
             return true;
         default:
             SkASSERT(kDone == fState);
             return false;
@@ skipping 24 matching lines @@
                           &needsSeparator);
         SkAddFlagToString(str, SkToBool(kHighQuality_BlurFlag & fBlurFlags), "HighQuality",
                           &needsSeparator);
     }
     str->append(")");
 
     // TODO: add optional "fBlurFilter->toString(str);" when SkMaskFilter::toString is added
     // alternatively we could cache the radius in SkBlurDrawLooper and just add it here
 }
 #endif