src/gpu/GrPipelineBuilder.h - skia - Git at Google

 /*
  * 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 "GrGpuResourceRef.h"
 #include "GrProcOptInfo.h"
 #include "GrRenderTarget.h"
 #include "GrUserStencilSettings.h"
 #include "GrXferProcessor.h"
 #include "SkMatrix.h"
 #include "SkRefCnt.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 and MSAA availability. 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&, bool useHWAA = false);

     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].get();
     }
     const GrFragmentProcessor* getCoverageFragmentProcessor(int idx) const {
         return fCoverageFragmentProcessors[idx].get();
     }

     void addColorFragmentProcessor(sk_sp<GrFragmentProcessor> processor) {
         SkASSERT(processor);
         fColorFragmentProcessors.push_back(std::move(processor));
     }

     void addCoverageFragmentProcessor(sk_sp<GrFragmentProcessor> processor) {
         SkASSERT(processor);
         fCoverageFragmentProcessors.push_back(std::move(processor));
     }

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

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

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

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

     /**
      * 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); }

         void addCoverageFragmentProcessor(sk_sp<GrFragmentProcessor> processor) {
             SkASSERT(this->isSet());
             return fPipelineBuilder->addCoverageFragmentProcessor(std::move(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.
      */
     void setXPFactory(sk_sp<GrXPFactory> xpFactory) {
         fXPFactory = std::move(xpFactory);
     }

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

     const GrXPFactory* getXPFactory() const {
         return fXPFactory.get();
     }

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

     /// @}


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

     bool hasUserStencilSettings() const { return !fUserStencilSettings->isUnused(); }
     const GrUserStencilSettings* getUserStencil() const { return fUserStencilSettings; }

     /**
      * Sets the user stencil settings for the next draw.
      * This class only stores pointers to stencil settings objects.
      * The caller guarantees the pointer will remain valid until it
      * changes or goes out of scope.
      * @param settings  the stencil settings to use.
      */
     void setUserStencil(const GrUserStencilSettings* settings) { fUserStencilSettings = settings; }
     void disableUserStencil() { fUserStencilSettings = &GrUserStencilSettings::kUnused; }

     /// @}

     ///////////////////////////////////////////////////////////////////////////
     /// @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,

         /**
          * Suppress linear -> sRGB conversion when rendering to sRGB render targets.
          */
         kDisableOutputConversionToSRGB_Flag = 0x04,

         /**
          * Allow sRGB -> linear conversion when reading from sRGB inputs.
          */
         kAllowSRGBInputs_Flag = 0x08,

         /**
          * Signals that one or more FPs need access to the distance vector field to the nearest
          * edge
          */
         kUsesDistanceVectorField_Flag = 0x10,

         kLast_Flag = kUsesDistanceVectorField_Flag,
     };

     bool isHWAntialias() const { return SkToBool(fFlags & kHWAntialias_Flag); }
     bool snapVerticesToPixelCenters() const {
         return SkToBool(fFlags & kSnapVerticesToPixelCenters_Flag); }
     bool getDisableOutputConversionToSRGB() const {
         return SkToBool(fFlags & kDisableOutputConversionToSRGB_Flag); }
     bool getAllowSRGBInputs() const {
         return SkToBool(fFlags & kAllowSRGBInputs_Flag); }
     bool getUsesDistanceVectorField() const {
         return SkToBool(fFlags & kUsesDistanceVectorField_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
     ////

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

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

     /// @}

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

     bool usePLSDstRead(const GrDrawBatch* batch) const;

 private:
     // 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, sk_sp<GrFragmentProcessor>> FragmentProcessorArray;

     uint32_t                                fFlags;
     const GrUserStencilSettings*            fUserStencilSettings;
     GrDrawFace                              fDrawFace;
     mutable sk_sp<GrXPFactory>              fXPFactory;
     FragmentProcessorArray                  fColorFragmentProcessors;
     FragmentProcessorArray                  fCoverageFragmentProcessors;

     friend class GrPipeline;
     friend class GrDrawTarget;
 };

 #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 "GrGpuResourceRef.h"
	#include "GrProcOptInfo.h"
	#include "GrRenderTarget.h"
	#include "GrUserStencilSettings.h"
	#include "GrXferProcessor.h"
	#include "SkMatrix.h"
	#include "SkRefCnt.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 and MSAA availability. 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&, bool useHWAA = false);

	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].get();
	}
	const GrFragmentProcessor* getCoverageFragmentProcessor(int idx) const {
	return fCoverageFragmentProcessors[idx].get();
	}

	void addColorFragmentProcessor(sk_sp<GrFragmentProcessor> processor) {
	SkASSERT(processor);
	fColorFragmentProcessors.push_back(std::move(processor));
	}

	void addCoverageFragmentProcessor(sk_sp<GrFragmentProcessor> processor) {
	SkASSERT(processor);
	fCoverageFragmentProcessors.push_back(std::move(processor));
	}

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

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

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

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

	/**
	* 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); }

	void addCoverageFragmentProcessor(sk_sp<GrFragmentProcessor> processor) {
	SkASSERT(this->isSet());
	return fPipelineBuilder->addCoverageFragmentProcessor(std::move(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.
	*/
	void setXPFactory(sk_sp<GrXPFactory> xpFactory) {
	fXPFactory = std::move(xpFactory);
	}

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

	const GrXPFactory* getXPFactory() const {
	return fXPFactory.get();
	}

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

	/// @}


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

	bool hasUserStencilSettings() const { return !fUserStencilSettings->isUnused(); }
	const GrUserStencilSettings* getUserStencil() const { return fUserStencilSettings; }

	/**
	* Sets the user stencil settings for the next draw.
	* This class only stores pointers to stencil settings objects.
	* The caller guarantees the pointer will remain valid until it
	* changes or goes out of scope.
	* @param settings the stencil settings to use.
	*/
	void setUserStencil(const GrUserStencilSettings* settings) { fUserStencilSettings = settings; }
	void disableUserStencil() { fUserStencilSettings = &GrUserStencilSettings::kUnused; }

	/// @}

	///////////////////////////////////////////////////////////////////////////
	/// @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,

	/**
	* Suppress linear -> sRGB conversion when rendering to sRGB render targets.
	*/
	kDisableOutputConversionToSRGB_Flag = 0x04,

	/**
	* Allow sRGB -> linear conversion when reading from sRGB inputs.
	*/
	kAllowSRGBInputs_Flag = 0x08,

	/**
	* Signals that one or more FPs need access to the distance vector field to the nearest
	* edge
	*/
	kUsesDistanceVectorField_Flag = 0x10,

	kLast_Flag = kUsesDistanceVectorField_Flag,
	};

	bool isHWAntialias() const { return SkToBool(fFlags & kHWAntialias_Flag); }
	bool snapVerticesToPixelCenters() const {
	return SkToBool(fFlags & kSnapVerticesToPixelCenters_Flag); }
	bool getDisableOutputConversionToSRGB() const {
	return SkToBool(fFlags & kDisableOutputConversionToSRGB_Flag); }
	bool getAllowSRGBInputs() const {
	return SkToBool(fFlags & kAllowSRGBInputs_Flag); }
	bool getUsesDistanceVectorField() const {
	return SkToBool(fFlags & kUsesDistanceVectorField_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
	////

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

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

	/// @}

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

	bool usePLSDstRead(const GrDrawBatch* batch) const;

	private:
	// 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, sk_sp<GrFragmentProcessor>> FragmentProcessorArray;

	uint32_t fFlags;
	const GrUserStencilSettings* fUserStencilSettings;
	GrDrawFace fDrawFace;
	mutable sk_sp<GrXPFactory> fXPFactory;
	FragmentProcessorArray fColorFragmentProcessors;
	FragmentProcessorArray fCoverageFragmentProcessors;

	friend class GrPipeline;
	friend class GrDrawTarget;
	};

	#endif