More carefully disable stages in Ganesh to avoid textures or effects

leaking between draw calls.

http://codereview.appspot.com/6353083/



git-svn-id: http://skia.googlecode.com/svn/trunk@4510 2bbb7eff-a529-9590-31e7-b0007b416f81

src/gpu/GrClipMaskManager.cpp

@@ -446,7 +446,7 @@ void GrClipMaskManager::drawTexture(GrTexture* target,
 
     fGpu->drawSimpleRect(rect, NULL, 1 << 0);
 
-    drawState->setTexture(0, NULL);
+    drawState->disableStage(0);
 }
 
 // get a texture to act as a temporary buffer for AA clip boolean operations

src/gpu/GrContext.cpp

@@ -1614,7 +1614,7 @@ void GrContext::setPaint(const GrPaint& paint) {
     
     // disable all stages not accessible via the paint
     for (int s = GrPaint::kTotalStages; s < GrDrawState::kNumStages; ++s) {
-        fDrawState->setTexture(s, NULL);
+        fDrawState->disableStage(s);
     }
 
     fDrawState->setColor(paint.fColor);

src/gpu/GrDrawState.h

@@ -225,14 +225,19 @@ public:
         }
         return true;
     }
+
+    void disableStage(int index) {
+        GrSafeSetNull(fTextures[index]);
+        fSamplerStates[index].setCustomStage(NULL);
+    }
+
     /**
      * Release all the textures and custom stages referred to by this
      * draw state.
      */
     void disableStages() {
         for (int i = 0; i < kNumStages; ++i) {
-            GrSafeSetNull(fTextures[i]);
-            fSamplerStates[i].setCustomStage(NULL);
+            this->disableStage(i);
         }
     }
 

src/gpu/GrSWMaskHelper.cpp

@@ -226,6 +226,6 @@ void GrSWMaskHelper::DrawToTargetWithPathMask(GrTexture* texture,
                             SK_Scalar1 * rect.fRight,
                             SK_Scalar1 * rect.fBottom);
     target->drawRect(dstRect, NULL, stageMask, srcRects, NULL);
-    drawState->setTexture(kPathMaskStage, NULL);
+    drawState->disableStage(kPathMaskStage);
 }
 

src/gpu/GrTextContext.cpp

@@ -68,7 +68,7 @@ void GrTextContext::flushGlyphs() {
         fMaxVertices = 0;
         fCurrVertex = 0;
         GrSafeSetNull(fCurrTexture);
-        drawState->setTexture(kGlyphMaskStage, NULL);
+        drawState->disableStage(kGlyphMaskStage);
     }
 }