src/gpu/GrPipelineBuilder.h - platform/external/skqp - Gitiles

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #ifndef GrPipelineBuilder_DEFINED
 #define GrPipelineBuilder_DEFINED

 #include "GrBlend.h"
 #include "GrCaps.h"
 #include "GrClip.h"
 #include "GrGpuResourceRef.h"
 #include "GrProcOptInfo.h"
 #include "GrRenderTarget.h"
 #include "GrStencil.h"
 #include "GrXferProcessor.h"
 #include "SkMatrix.h"
 #include "effects/GrCoverageSetOpXP.h"
 #include "effects/GrDisableColorXP.h"
 #include "effects/GrPorterDuffXferProcessor.h"
 #include "effects/GrSimpleTextureEffect.h"

 class GrDrawBatch;
 class GrCaps;
 class GrPaint;
 class GrTexture;

 class GrPipelineBuilder : public SkNoncopyable {
 public:
     GrPipelineBuilder();

     /**
      * Initializes the GrPipelineBuilder based on a GrPaint, render target, and clip. Note
      * that GrPipelineBuilder encompasses more than GrPaint. Aspects of GrPipelineBuilder that have
      * no GrPaint equivalents are set to default values with the exception of vertex attribute state
      * which is unmodified by this function and clipping which will be enabled.
      */
     GrPipelineBuilder(const GrPaint&, GrRenderTarget*, const GrClip&);

     virtual ~GrPipelineBuilder();

     ///////////////////////////////////////////////////////////////////////////
     /// @name Fragment Processors
     ///
     /// GrFragmentProcessors are used to compute per-pixel color and per-pixel fractional coverage.
     /// There are two chains of FPs, one for color and one for coverage. The first FP in each
     /// chain gets the initial color/coverage from the GrPrimitiveProcessor. It computes an output
     /// color/coverage which is fed to the next FP in the chain. The last color and coverage FPs
     /// feed their output to the GrXferProcessor which controls blending.
     ////

     int numColorFragmentProcessors() const { return fColorFragmentProcessors.count(); }
     int numCoverageFragmentProcessors() const { return fCoverageFragmentProcessors.count(); }
     int numFragmentProcessors() const { return this->numColorFragmentProcessors() +
                                                this->numCoverageFragmentProcessors(); }

     const GrFragmentProcessor* getColorFragmentProcessor(int idx) const {
         return fColorFragmentProcessors[idx];
     }
     const GrFragmentProcessor* getCoverageFragmentProcessor(int idx) const {
         return fCoverageFragmentProcessors[idx];
     }

     const GrFragmentProcessor* addColorFragmentProcessor(const GrFragmentProcessor* processor) {
         SkASSERT(processor);
         fColorFragmentProcessors.push_back(SkRef(processor));
         return processor;
     }

     const GrFragmentProcessor* addCoverageFragmentProcessor(const GrFragmentProcessor* processor) {
         SkASSERT(processor);
         fCoverageFragmentProcessors.push_back(SkRef(processor));
         return processor;
     }

     /**
      * Creates a GrSimpleTextureEffect that uses local coords as texture coordinates.
      */
     void addColorTextureProcessor(GrTexture* texture, const SkMatrix& matrix) {
         this->addColorFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix))->unref();
     }

     void addCoverageTextureProcessor(GrTexture* texture, const SkMatrix& matrix) {
         this->addCoverageFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix))->unref();
     }

     void addColorTextureProcessor(GrTexture* texture,
                                   const SkMatrix& matrix,
                                   const GrTextureParams& params) {
         this->addColorFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix,
                                                                       params))->unref();
     }

     void addCoverageTextureProcessor(GrTexture* texture,
                                      const SkMatrix& matrix,
                                      const GrTextureParams& params) {
         this->addCoverageFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix,
                                                                          params))->unref();
     }

     /**
      * When this object is destroyed it will remove any color/coverage FPs from the pipeline builder
      * that were added after its constructor.
      * This class can transiently modify its "const" GrPipelineBuilder object but will restore it
      * when done - so it is notionally "const" correct.
      */
     class AutoRestoreFragmentProcessorState : public ::SkNoncopyable {
     public:
         AutoRestoreFragmentProcessorState()
             : fPipelineBuilder(nullptr)
             , fColorEffectCnt(0)
             , fCoverageEffectCnt(0) {}

         AutoRestoreFragmentProcessorState(const GrPipelineBuilder& ds)
             : fPipelineBuilder(nullptr)
             , fColorEffectCnt(0)
             , fCoverageEffectCnt(0) {
             this->set(&ds);
         }

         ~AutoRestoreFragmentProcessorState() { this->set(nullptr); }

         void set(const GrPipelineBuilder* ds);

         bool isSet() const { return SkToBool(fPipelineBuilder); }

         const GrFragmentProcessor* addCoverageFragmentProcessor(
             const GrFragmentProcessor* processor) {
             SkASSERT(this->isSet());
             return fPipelineBuilder->addCoverageFragmentProcessor(processor);
         }

     private:
         // notionally const (as marginalia)
         GrPipelineBuilder*    fPipelineBuilder;
         int                   fColorEffectCnt;
         int                   fCoverageEffectCnt;
     };

     /// @}

     ///////////////////////////////////////////////////////////////////////////
     /// @name Blending
     ////

     /**
      * Installs a GrXPFactory. This object controls how src color, fractional pixel coverage,
      * and the dst color are blended.
      */
     const GrXPFactory* setXPFactory(const GrXPFactory* xpFactory) {
         fXPFactory.reset(SkRef(xpFactory));
         return xpFactory;
     }

     /**
      * Sets a GrXPFactory that will ignore src color and perform a set operation between the draws
      * output coverage and the destination. This is useful to render coverage masks as CSG.
      */
     void setCoverageSetOpXPFactory(SkRegion::Op regionOp, bool invertCoverage = false) {
         fXPFactory.reset(GrCoverageSetOpXPFactory::Create(regionOp, invertCoverage));
     }

     /**
      * Sets a GrXPFactory that disables color writes to the destination. This is useful when
      * rendering to the stencil buffer.
      */
     void setDisableColorXPFactory() {
         fXPFactory.reset(GrDisableColorXPFactory::Create());
     }

     const GrXPFactory* getXPFactory() const {
         if (!fXPFactory) {
             fXPFactory.reset(GrPorterDuffXPFactory::Create(SkXfermode::kSrc_Mode));
         }
         return fXPFactory.get();
     }

     /**
      * Checks whether the xp will need destination in a texture to correctly blend.
      */
     bool willXPNeedDstTexture(const GrCaps& caps, const GrProcOptInfo& colorPOI,
                               const GrProcOptInfo& coveragePOI) const;

     /// @}


     ///////////////////////////////////////////////////////////////////////////
     /// @name Render Target
     ////

     /**
      * Retrieves the currently set render-target.
      *
      * @return    The currently set render target.
      */
     GrRenderTarget* getRenderTarget() const { return fRenderTarget.get(); }

     /**
      * Sets the render-target used at the next drawing call
      *
      * @param target  The render target to set.
      */
     void setRenderTarget(GrRenderTarget* target) { fRenderTarget.reset(SkSafeRef(target)); }

     /**
      * Returns whether the rasterizer and stencil test (if any) will run at a higher sample rate
      * than the color buffer. In is scenario, the higher sample rate is resolved during blending.
      */
     bool hasMixedSamples() const {
         return fRenderTarget->hasMixedSamples() &&
                (this->isHWAntialias() || !fStencilSettings.isDisabled());
     }

     /// @}

     ///////////////////////////////////////////////////////////////////////////
     /// @name Stencil
     ////

     const GrStencilSettings& getStencil() const { return fStencilSettings; }

     /**
      * Sets the stencil settings to use for the next draw.
      * Changing the clip has the side-effect of possibly zeroing
      * out the client settable stencil bits. So multipass algorithms
      * using stencil should not change the clip between passes.
      * @param settings  the stencil settings to use.
      */
     void setStencil(const GrStencilSettings& settings) { fStencilSettings = settings; }

     GrStencilSettings* stencil() { return &fStencilSettings; }

     /**
      * AutoRestoreStencil
      *
      * This simple struct saves and restores the stencil settings
      * This class can transiently modify its "const" GrPipelineBuilder object but will restore it
      * when done - so it is notionally "const" correct.
      */
     class AutoRestoreStencil : public ::SkNoncopyable {
     public:
         AutoRestoreStencil() : fPipelineBuilder(nullptr) {}

         AutoRestoreStencil(const GrPipelineBuilder& ds) : fPipelineBuilder(nullptr) { this->set(&ds); }

         ~AutoRestoreStencil() { this->set(nullptr); }

         void set(const GrPipelineBuilder* ds) {
             if (fPipelineBuilder) {
                 fPipelineBuilder->setStencil(fStencilSettings);
             }
             fPipelineBuilder = const_cast<GrPipelineBuilder*>(ds);
             if (ds) {
                 fStencilSettings = ds->getStencil();
             }
         }

         bool isSet() const { return SkToBool(fPipelineBuilder); }

         void setStencil(const GrStencilSettings& settings) {
             SkASSERT(this->isSet());
             fPipelineBuilder->setStencil(settings);
         }

     private:
         // notionally const (as marginalia)
         GrPipelineBuilder*  fPipelineBuilder;
         GrStencilSettings   fStencilSettings;
     };


     /// @}

     ///////////////////////////////////////////////////////////////////////////
     /// @name State Flags
     ////

     /**
      *  Flags that affect rendering. Controlled using enable/disableState(). All
      *  default to disabled.
      */
     enum Flags {
         /**
          * Perform HW anti-aliasing. This means either HW FSAA, if supported by the render target,
          * or smooth-line rendering if a line primitive is drawn and line smoothing is supported by
          * the 3D API.
          */
         kHWAntialias_Flag   = 0x01,

         /**
          * Modifies the vertex shader so that vertices will be positioned at pixel centers.
          */
         kSnapVerticesToPixelCenters_Flag = 0x02,

         kLast_Flag = kSnapVerticesToPixelCenters_Flag,
     };

     bool isHWAntialias() const { return SkToBool(fFlags & kHWAntialias_Flag); }
     bool snapVerticesToPixelCenters() const {
         return SkToBool(fFlags & kSnapVerticesToPixelCenters_Flag); }

     /**
      * Enable render state settings.
      *
      * @param flags bitfield of Flags specifying the states to enable
      */
     void enableState(uint32_t flags) { fFlags |= flags; }

     /**
      * Disable render state settings.
      *
      * @param flags bitfield of Flags specifying the states to disable
      */
     void disableState(uint32_t flags) { fFlags &= ~(flags); }

     /**
      * Enable or disable flags based on a boolean.
      *
      * @param flags bitfield of Flags to enable or disable
      * @param enable    if true enable stateBits, otherwise disable
      */
     void setState(uint32_t flags, bool enable) {
         if (enable) {
             this->enableState(flags);
         } else {
             this->disableState(flags);
         }
     }

     /// @}

     ///////////////////////////////////////////////////////////////////////////
     /// @name Face Culling
     ////

     enum DrawFace {
         kInvalid_DrawFace = -1,

         kBoth_DrawFace,
         kCCW_DrawFace,
         kCW_DrawFace,
     };

     /**
      * Gets whether the target is drawing clockwise, counterclockwise,
      * or both faces.
      * @return the current draw face(s).
      */
     DrawFace getDrawFace() const { return fDrawFace; }

     /**
      * Controls whether clockwise, counterclockwise, or both faces are drawn.
      * @param face  the face(s) to draw.
      */
     void setDrawFace(DrawFace face) {
         SkASSERT(kInvalid_DrawFace != face);
         fDrawFace = face;
     }

     /// @}

     ///////////////////////////////////////////////////////////////////////////

     const GrProcOptInfo& colorProcInfo(const GrDrawBatch* batch) const {
         this->calcColorInvariantOutput(batch);
         return fColorProcInfo;
     }

     const GrProcOptInfo& coverageProcInfo(const GrDrawBatch* batch) const {
         this->calcCoverageInvariantOutput(batch);
         return fCoverageProcInfo;
     }

     void setClip(const GrClip& clip) { fClip = clip; }
     const GrClip& clip() const { return fClip; }

 private:
     // Calculating invariant color / coverage information is expensive, so we partially cache the
     // results.
     //
     // canUseFracCoveragePrimProc() - Called in regular skia draw, caches results but only for a
     //                                specific color and coverage.  May be called multiple times
     // GrOptDrawState constructor - never caches results

     /**
      * GrBatch provides the initial seed for these loops based off of its initial geometry data
      */
     void calcColorInvariantOutput(const GrDrawBatch*) const;
     void calcCoverageInvariantOutput(const GrDrawBatch*) const;

     // Some of the auto restore objects assume that no effects are removed during their lifetime.
     // This is used to assert that this condition holds.
     SkDEBUGCODE(mutable int fBlockEffectRemovalCnt;)

     typedef SkSTArray<4, const GrFragmentProcessor*, true> FragmentProcessorArray;

     SkAutoTUnref<GrRenderTarget>            fRenderTarget;
     uint32_t                                fFlags;
     GrStencilSettings                       fStencilSettings;
     DrawFace                                fDrawFace;
     mutable SkAutoTUnref<const GrXPFactory> fXPFactory;
     FragmentProcessorArray                  fColorFragmentProcessors;
     FragmentProcessorArray                  fCoverageFragmentProcessors;
     GrClip                                  fClip;

     mutable GrProcOptInfo fColorProcInfo;
     mutable GrProcOptInfo fCoverageProcInfo;

     friend class GrPipeline;
 };

 #endif
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#ifndef GrPipelineBuilder_DEFINED
	#define GrPipelineBuilder_DEFINED

	#include "GrBlend.h"
	#include "GrCaps.h"
	#include "GrClip.h"
	#include "GrGpuResourceRef.h"
	#include "GrProcOptInfo.h"
	#include "GrRenderTarget.h"
	#include "GrStencil.h"
	#include "GrXferProcessor.h"
	#include "SkMatrix.h"
	#include "effects/GrCoverageSetOpXP.h"
	#include "effects/GrDisableColorXP.h"
	#include "effects/GrPorterDuffXferProcessor.h"
	#include "effects/GrSimpleTextureEffect.h"

	class GrDrawBatch;
	class GrCaps;
	class GrPaint;
	class GrTexture;

	class GrPipelineBuilder : public SkNoncopyable {
	public:
	GrPipelineBuilder();

	/**
	* Initializes the GrPipelineBuilder based on a GrPaint, render target, and clip. Note
	* that GrPipelineBuilder encompasses more than GrPaint. Aspects of GrPipelineBuilder that have
	* no GrPaint equivalents are set to default values with the exception of vertex attribute state
	* which is unmodified by this function and clipping which will be enabled.
	*/
	GrPipelineBuilder(const GrPaint&, GrRenderTarget*, const GrClip&);

	virtual ~GrPipelineBuilder();

	///////////////////////////////////////////////////////////////////////////
	/// @name Fragment Processors
	///
	/// GrFragmentProcessors are used to compute per-pixel color and per-pixel fractional coverage.
	/// There are two chains of FPs, one for color and one for coverage. The first FP in each
	/// chain gets the initial color/coverage from the GrPrimitiveProcessor. It computes an output
	/// color/coverage which is fed to the next FP in the chain. The last color and coverage FPs
	/// feed their output to the GrXferProcessor which controls blending.
	////

	int numColorFragmentProcessors() const { return fColorFragmentProcessors.count(); }
	int numCoverageFragmentProcessors() const { return fCoverageFragmentProcessors.count(); }
	int numFragmentProcessors() const { return this->numColorFragmentProcessors() +
	this->numCoverageFragmentProcessors(); }

	const GrFragmentProcessor* getColorFragmentProcessor(int idx) const {
	return fColorFragmentProcessors[idx];
	}
	const GrFragmentProcessor* getCoverageFragmentProcessor(int idx) const {
	return fCoverageFragmentProcessors[idx];
	}

	const GrFragmentProcessor* addColorFragmentProcessor(const GrFragmentProcessor* processor) {
	SkASSERT(processor);
	fColorFragmentProcessors.push_back(SkRef(processor));
	return processor;
	}

	const GrFragmentProcessor* addCoverageFragmentProcessor(const GrFragmentProcessor* processor) {
	SkASSERT(processor);
	fCoverageFragmentProcessors.push_back(SkRef(processor));
	return processor;
	}

	/**
	* Creates a GrSimpleTextureEffect that uses local coords as texture coordinates.
	*/
	void addColorTextureProcessor(GrTexture* texture, const SkMatrix& matrix) {
	this->addColorFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix))->unref();
	}

	void addCoverageTextureProcessor(GrTexture* texture, const SkMatrix& matrix) {
	this->addCoverageFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix))->unref();
	}

	void addColorTextureProcessor(GrTexture* texture,
	const SkMatrix& matrix,
	const GrTextureParams& params) {
	this->addColorFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix,
	params))->unref();
	}

	void addCoverageTextureProcessor(GrTexture* texture,
	const SkMatrix& matrix,
	const GrTextureParams& params) {
	this->addCoverageFragmentProcessor(GrSimpleTextureEffect::Create(texture, matrix,
	params))->unref();
	}

	/**
	* When this object is destroyed it will remove any color/coverage FPs from the pipeline builder
	* that were added after its constructor.
	* This class can transiently modify its "const" GrPipelineBuilder object but will restore it
	* when done - so it is notionally "const" correct.
	*/
	class AutoRestoreFragmentProcessorState : public ::SkNoncopyable {
	public:
	AutoRestoreFragmentProcessorState()
	: fPipelineBuilder(nullptr)
	, fColorEffectCnt(0)
	, fCoverageEffectCnt(0) {}

	AutoRestoreFragmentProcessorState(const GrPipelineBuilder& ds)
	: fPipelineBuilder(nullptr)
	, fColorEffectCnt(0)
	, fCoverageEffectCnt(0) {
	this->set(&ds);
	}

	~AutoRestoreFragmentProcessorState() { this->set(nullptr); }

	void set(const GrPipelineBuilder* ds);

	bool isSet() const { return SkToBool(fPipelineBuilder); }

	const GrFragmentProcessor* addCoverageFragmentProcessor(
	const GrFragmentProcessor* processor) {
	SkASSERT(this->isSet());
	return fPipelineBuilder->addCoverageFragmentProcessor(processor);
	}

	private:
	// notionally const (as marginalia)
	GrPipelineBuilder* fPipelineBuilder;
	int fColorEffectCnt;
	int fCoverageEffectCnt;
	};

	/// @}

	///////////////////////////////////////////////////////////////////////////
	/// @name Blending
	////

	/**
	* Installs a GrXPFactory. This object controls how src color, fractional pixel coverage,
	* and the dst color are blended.
	*/
	const GrXPFactory* setXPFactory(const GrXPFactory* xpFactory) {
	fXPFactory.reset(SkRef(xpFactory));
	return xpFactory;
	}

	/**
	* Sets a GrXPFactory that will ignore src color and perform a set operation between the draws
	* output coverage and the destination. This is useful to render coverage masks as CSG.
	*/
	void setCoverageSetOpXPFactory(SkRegion::Op regionOp, bool invertCoverage = false) {
	fXPFactory.reset(GrCoverageSetOpXPFactory::Create(regionOp, invertCoverage));
	}

	/**
	* Sets a GrXPFactory that disables color writes to the destination. This is useful when
	* rendering to the stencil buffer.
	*/
	void setDisableColorXPFactory() {
	fXPFactory.reset(GrDisableColorXPFactory::Create());
	}

	const GrXPFactory* getXPFactory() const {
	if (!fXPFactory) {
	fXPFactory.reset(GrPorterDuffXPFactory::Create(SkXfermode::kSrc_Mode));
	}
	return fXPFactory.get();
	}

	/**
	* Checks whether the xp will need destination in a texture to correctly blend.
	*/
	bool willXPNeedDstTexture(const GrCaps& caps, const GrProcOptInfo& colorPOI,
	const GrProcOptInfo& coveragePOI) const;

	/// @}


	///////////////////////////////////////////////////////////////////////////
	/// @name Render Target
	////

	/**
	* Retrieves the currently set render-target.
	*
	* @return The currently set render target.
	*/
	GrRenderTarget* getRenderTarget() const { return fRenderTarget.get(); }

	/**
	* Sets the render-target used at the next drawing call
	*
	* @param target The render target to set.
	*/
	void setRenderTarget(GrRenderTarget* target) { fRenderTarget.reset(SkSafeRef(target)); }

	/**
	* Returns whether the rasterizer and stencil test (if any) will run at a higher sample rate
	* than the color buffer. In is scenario, the higher sample rate is resolved during blending.
	*/
	bool hasMixedSamples() const {
	return fRenderTarget->hasMixedSamples() &&
	(this->isHWAntialias() \|\| !fStencilSettings.isDisabled());
	}

	/// @}

	///////////////////////////////////////////////////////////////////////////
	/// @name Stencil
	////

	const GrStencilSettings& getStencil() const { return fStencilSettings; }

	/**
	* Sets the stencil settings to use for the next draw.
	* Changing the clip has the side-effect of possibly zeroing
	* out the client settable stencil bits. So multipass algorithms
	* using stencil should not change the clip between passes.
	* @param settings the stencil settings to use.
	*/
	void setStencil(const GrStencilSettings& settings) { fStencilSettings = settings; }

	GrStencilSettings* stencil() { return &fStencilSettings; }

	/**
	* AutoRestoreStencil
	*
	* This simple struct saves and restores the stencil settings
	* This class can transiently modify its "const" GrPipelineBuilder object but will restore it
	* when done - so it is notionally "const" correct.
	*/
	class AutoRestoreStencil : public ::SkNoncopyable {
	public:
	AutoRestoreStencil() : fPipelineBuilder(nullptr) {}

	AutoRestoreStencil(const GrPipelineBuilder& ds) : fPipelineBuilder(nullptr) { this->set(&ds); }

	~AutoRestoreStencil() { this->set(nullptr); }

	void set(const GrPipelineBuilder* ds) {
	if (fPipelineBuilder) {
	fPipelineBuilder->setStencil(fStencilSettings);
	}
	fPipelineBuilder = const_cast<GrPipelineBuilder*>(ds);
	if (ds) {
	fStencilSettings = ds->getStencil();
	}
	}

	bool isSet() const { return SkToBool(fPipelineBuilder); }

	void setStencil(const GrStencilSettings& settings) {
	SkASSERT(this->isSet());
	fPipelineBuilder->setStencil(settings);
	}

	private:
	// notionally const (as marginalia)
	GrPipelineBuilder* fPipelineBuilder;
	GrStencilSettings fStencilSettings;
	};


	/// @}

	///////////////////////////////////////////////////////////////////////////
	/// @name State Flags
	////

	/**
	* Flags that affect rendering. Controlled using enable/disableState(). All
	* default to disabled.
	*/
	enum Flags {
	/**
	* Perform HW anti-aliasing. This means either HW FSAA, if supported by the render target,
	* or smooth-line rendering if a line primitive is drawn and line smoothing is supported by
	* the 3D API.
	*/
	kHWAntialias_Flag = 0x01,

	/**
	* Modifies the vertex shader so that vertices will be positioned at pixel centers.
	*/
	kSnapVerticesToPixelCenters_Flag = 0x02,

	kLast_Flag = kSnapVerticesToPixelCenters_Flag,
	};

	bool isHWAntialias() const { return SkToBool(fFlags & kHWAntialias_Flag); }
	bool snapVerticesToPixelCenters() const {
	return SkToBool(fFlags & kSnapVerticesToPixelCenters_Flag); }

	/**
	* Enable render state settings.
	*
	* @param flags bitfield of Flags specifying the states to enable
	*/
	void enableState(uint32_t flags) { fFlags \|= flags; }

	/**
	* Disable render state settings.
	*
	* @param flags bitfield of Flags specifying the states to disable
	*/
	void disableState(uint32_t flags) { fFlags &= ~(flags); }

	/**
	* Enable or disable flags based on a boolean.
	*
	* @param flags bitfield of Flags to enable or disable
	* @param enable if true enable stateBits, otherwise disable
	*/
	void setState(uint32_t flags, bool enable) {
	if (enable) {
	this->enableState(flags);
	} else {
	this->disableState(flags);
	}
	}

	/// @}

	///////////////////////////////////////////////////////////////////////////
	/// @name Face Culling
	////

	enum DrawFace {
	kInvalid_DrawFace = -1,

	kBoth_DrawFace,
	kCCW_DrawFace,
	kCW_DrawFace,
	};

	/**
	* Gets whether the target is drawing clockwise, counterclockwise,
	* or both faces.
	* @return the current draw face(s).
	*/
	DrawFace getDrawFace() const { return fDrawFace; }

	/**
	* Controls whether clockwise, counterclockwise, or both faces are drawn.
	* @param face the face(s) to draw.
	*/
	void setDrawFace(DrawFace face) {
	SkASSERT(kInvalid_DrawFace != face);
	fDrawFace = face;
	}

	/// @}

	///////////////////////////////////////////////////////////////////////////

	const GrProcOptInfo& colorProcInfo(const GrDrawBatch* batch) const {
	this->calcColorInvariantOutput(batch);
	return fColorProcInfo;
	}

	const GrProcOptInfo& coverageProcInfo(const GrDrawBatch* batch) const {
	this->calcCoverageInvariantOutput(batch);
	return fCoverageProcInfo;
	}

	void setClip(const GrClip& clip) { fClip = clip; }
	const GrClip& clip() const { return fClip; }

	private:
	// Calculating invariant color / coverage information is expensive, so we partially cache the
	// results.
	//
	// canUseFracCoveragePrimProc() - Called in regular skia draw, caches results but only for a
	// specific color and coverage. May be called multiple times
	// GrOptDrawState constructor - never caches results

	/**
	* GrBatch provides the initial seed for these loops based off of its initial geometry data
	*/
	void calcColorInvariantOutput(const GrDrawBatch*) const;
	void calcCoverageInvariantOutput(const GrDrawBatch*) const;

	// Some of the auto restore objects assume that no effects are removed during their lifetime.
	// This is used to assert that this condition holds.
	SkDEBUGCODE(mutable int fBlockEffectRemovalCnt;)

	typedef SkSTArray<4, const GrFragmentProcessor*, true> FragmentProcessorArray;

	SkAutoTUnref<GrRenderTarget> fRenderTarget;
	uint32_t fFlags;
	GrStencilSettings fStencilSettings;
	DrawFace fDrawFace;
	mutable SkAutoTUnref<const GrXPFactory> fXPFactory;
	FragmentProcessorArray fColorFragmentProcessors;
	FragmentProcessorArray fCoverageFragmentProcessors;
	GrClip fClip;

	mutable GrProcOptInfo fColorProcInfo;
	mutable GrProcOptInfo fCoverageProcInfo;

	friend class GrPipeline;
	};

	#endif