skia2/include/gpu/GrPathRendererChain.h
kkinnunen 1899651ffc Extract gpu line dashing to GrDashLinePathRenderer
Move line dashing logic from GrContext::drawPath to
GrDashLinePathRenderer. This makes it possible to let path renderers render arbitrary dashed paths.

End goal is to implement dashing in GrStencilAndCoverPathRenderer.

Review URL: https://codereview.chromium.org/1100073003
2015-04-26 23:18:50 -07:00

84 lines
2.8 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrPathRendererChain_DEFINED
#define GrPathRendererChain_DEFINED
#include "SkRefCnt.h"
#include "SkTArray.h"
class GrContext;
class GrDrawTarget;
class GrPathRenderer;
class GrPipelineBuilder;
class GrStrokeInfo;
class SkMatrix;
class SkPath;
/**
* Keeps track of an ordered list of path renderers. When a path needs to be
* drawn this list is scanned to find the most preferred renderer. To add your
* path renderer to the list implement the GrPathRenderer::AddPathRenderers
* function.
*/
class GrPathRendererChain : public SkRefCnt {
public:
// See comments in GrPathRenderer.h
enum StencilSupport {
kNoSupport_StencilSupport,
kStencilOnly_StencilSupport,
kNoRestriction_StencilSupport,
};
SK_DECLARE_INST_COUNT(GrPathRendererChain)
GrPathRendererChain(GrContext* context);
~GrPathRendererChain();
// takes a ref and unrefs in destructor
GrPathRenderer* addPathRenderer(GrPathRenderer* pr);
/** Documents how the caller plans to use a GrPathRenderer to draw a path. It affects the PR
returned by getPathRenderer */
enum DrawType {
kColor_DrawType, // draw to the color buffer, no AA
kColorAntiAlias_DrawType, // draw to color buffer, with partial coverage AA
kStencilOnly_DrawType, // draw just to the stencil buffer
kStencilAndColor_DrawType, // draw the stencil and color buffer, no AA
kStencilAndColorAntiAlias_DrawType // draw the stencil and color buffer, with partial
// coverage AA.
};
/** Returns a GrPathRenderer compatible with the request if one is available. If the caller
is drawing the path to the stencil buffer then stencilSupport can be used to determine
whether the path can be rendered with arbitrary stencil rules or not. See comments on
StencilSupport in GrPathRenderer.h. */
GrPathRenderer* getPathRenderer(const GrDrawTarget* target,
const GrPipelineBuilder*,
const SkMatrix& viewMatrix,
const SkPath& path,
const GrStrokeInfo& stroke,
DrawType drawType,
StencilSupport* stencilSupport);
private:
GrPathRendererChain();
void init();
enum {
kPreAllocCount = 8,
};
bool fInit;
GrContext* fOwner;
SkSTArray<kPreAllocCount, GrPathRenderer*, true> fChain;
typedef SkRefCnt INHERITED;
};
#endif