Use GrConvexPolyEffect when clip is a single convex polygon

src/gpu/GrClipMaskManager.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 "GrClipMaskManager.h"
 #include "GrAAConvexPathRenderer.h"
 #include "GrAAHairLinePathRenderer.h"
 #include "GrAARectRenderer.h"
 #include "GrDrawTargetCaps.h"
 #include "GrGpu.h"
 #include "GrPaint.h"
 #include "GrPathRenderer.h"
 #include "GrRenderTarget.h"
 #include "GrStencilBuffer.h"
 #include "GrSWMaskHelper.h"
 #include "effects/GrTextureDomain.h"
+#include "effects/GrConvexPolyEffect.h"
 #include "SkRasterClip.h"
 #include "SkStrokeRec.h"
 #include "SkTLazy.h"
 
 #define GR_AA_CLIP 1
 
 typedef SkClipStack::Element Element;
 
 using namespace GrReducedClip;
 
@@ skipping 115 matching lines @@
             }
         }
     }
 
     if (ignoreClip) {
         fGpu->disableScissor();
         this->setGpuStencil();
         return true;
     }
 
+    // If there is only one clip element and it is a convex polygon we just install an effect that
+    // clips against the edges.

[robertphillips, 2014/01/31 19:58:58]

Will inverse filled paths work correctly?

[bsalomon, 2014/01/31 20:05:32]

Yup, the effect factory fails.

+    if (1 == elements.count() && SkClipStack::Element::kPath_Type == elements.tail()->getType() &&
+        SkRegion::kReplace_Op == elements.tail()->getOp()) {
+        const SkPath& p = elements.tail()->getPath();
+        bool isAA = GR_AA_CLIP && elements.tail()->isAA();
+        SkAutoTUnref<GrEffectRef> effect;
+        if (rt->isMultisampled()) {
+            // A coverage effect for AA clipping won't play nicely with MSAA.
+            if (!isAA) {
+                effect.reset(GrConvexPolyEffect::Create(GrConvexPolyEffect::kFillNoAA_EdgeType, p));
+            }
+        } else {
+            GrConvexPolyEffect::EdgeType type = isAA ? GrConvexPolyEffect::kFillAA_EdgeType :
+                                                       GrConvexPolyEffect::kFillNoAA_EdgeType;
+            effect.reset(GrConvexPolyEffect::Create(type, p));
+        }
+        if (effect) {
+            are->set(fGpu->drawState());
+            fGpu->drawState()->addCoverageEffect(effect);
+            fGpu->disableScissor();
+            this->setGpuStencil();
+            return true;
+        }
+    }
+
 #if GR_AA_CLIP
-    // TODO: catch isRect && requiresAA and use clip planes if available rather than a mask.
-
     // If MSAA is enabled we can do everything in the stencil buffer.
     if (0 == rt->numSamples() && requiresAA) {
         GrTexture* result = NULL;
 
         if (this->useSWOnlyPath(elements)) {
             // The clip geometry is complex enough that it will be more efficient to create it
             // entirely in software
             result = this->createSoftwareClipMask(genID,
                                                   initialState,
                                                   elements,
@@ skipping 866 matching lines @@
 
     // TODO: dynamically attach a stencil buffer
     int stencilBits = 0;
     GrStencilBuffer* stencilBuffer =
         drawState.getRenderTarget()->getStencilBuffer();
     if (NULL != stencilBuffer) {
         stencilBits = stencilBuffer->bits();
         this->adjustStencilParams(settings, clipMode, stencilBits);
     }
 }