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      1 
      2 /*
      3  * Copyright 2012 Google Inc.
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 
     10 #include "GrStencilAndCoverPathRenderer.h"
     11 #include "GrContext.h"
     12 #include "GrDrawTargetCaps.h"
     13 #include "GrGpu.h"
     14 #include "GrPath.h"
     15 #include "SkStrokeRec.h"
     16 
     17 GrPathRenderer* GrStencilAndCoverPathRenderer::Create(GrContext* context) {
     18     SkASSERT(NULL != context);
     19     SkASSERT(NULL != context->getGpu());
     20     if (context->getGpu()->caps()->pathRenderingSupport()) {
     21         return SkNEW_ARGS(GrStencilAndCoverPathRenderer, (context->getGpu()));
     22     } else {
     23         return NULL;
     24     }
     25 }
     26 
     27 GrStencilAndCoverPathRenderer::GrStencilAndCoverPathRenderer(GrGpu* gpu) {
     28     SkASSERT(gpu->caps()->pathRenderingSupport());
     29     fGpu = gpu;
     30     gpu->ref();
     31 }
     32 
     33 GrStencilAndCoverPathRenderer::~GrStencilAndCoverPathRenderer() {
     34     fGpu->unref();
     35 }
     36 
     37 bool GrStencilAndCoverPathRenderer::canDrawPath(const SkPath& path,
     38                                                 const SkStrokeRec& stroke,
     39                                                 const GrDrawTarget* target,
     40                                                 bool antiAlias) const {
     41     return !stroke.isHairlineStyle() &&
     42            !antiAlias && // doesn't do per-path AA, relies on the target having MSAA
     43            NULL != target->getDrawState().getRenderTarget()->getStencilBuffer() &&
     44            target->getDrawState().getStencil().isDisabled();
     45 }
     46 
     47 GrPathRenderer::StencilSupport GrStencilAndCoverPathRenderer::onGetStencilSupport(
     48                                                         const SkPath&,
     49                                                         const SkStrokeRec& ,
     50                                                         const GrDrawTarget*) const {
     51     return GrPathRenderer::kStencilOnly_StencilSupport;
     52 }
     53 
     54 void GrStencilAndCoverPathRenderer::onStencilPath(const SkPath& path,
     55                                                   const SkStrokeRec& stroke,
     56                                                   GrDrawTarget* target) {
     57     SkASSERT(!path.isInverseFillType());
     58     SkAutoTUnref<GrPath> p(fGpu->getContext()->createPath(path, stroke));
     59     target->stencilPath(p, path.getFillType());
     60 }
     61 
     62 bool GrStencilAndCoverPathRenderer::onDrawPath(const SkPath& path,
     63                                                const SkStrokeRec& stroke,
     64                                                GrDrawTarget* target,
     65                                                bool antiAlias) {
     66     SkASSERT(!antiAlias);
     67     SkASSERT(!stroke.isHairlineStyle());
     68 
     69     GrDrawState* drawState = target->drawState();
     70     SkASSERT(drawState->getStencil().isDisabled());
     71 
     72     SkAutoTUnref<GrPath> p(fGpu->getContext()->createPath(path, stroke));
     73 
     74     if (path.isInverseFillType()) {
     75         GR_STATIC_CONST_SAME_STENCIL(kInvertedStencilPass,
     76             kZero_StencilOp,
     77             kZero_StencilOp,
     78             // We know our rect will hit pixels outside the clip and the user bits will be 0
     79             // outside the clip. So we can't just fill where the user bits are 0. We also need to
     80             // check that the clip bit is set.
     81             kEqualIfInClip_StencilFunc,
     82             0xffff,
     83             0x0000,
     84             0xffff);
     85 
     86         *drawState->stencil() = kInvertedStencilPass;
     87     } else {
     88         GR_STATIC_CONST_SAME_STENCIL(kStencilPass,
     89             kZero_StencilOp,
     90             kZero_StencilOp,
     91             kNotEqual_StencilFunc,
     92             0xffff,
     93             0x0000,
     94             0xffff);
     95 
     96         *drawState->stencil() = kStencilPass;
     97     }
     98 
     99     target->drawPath(p, path.getFillType());
    100 
    101     target->drawState()->stencil()->setDisabled();
    102     return true;
    103 }
    104