GrXPFactory Class Reference

#include <GrXferProcessor.h>

Inheritance diagram for GrXPFactory:

Public Types
enum class	AnalysisProperties : unsigned {   kNone = 0x0 , kReadsDstInShader = 0x1 , kCompatibleWithCoverageAsAlpha = 0x2 , kIgnoresInputColor = 0x4 ,   kRequiresDstTexture = 0x10 , kRequiresNonOverlappingDraws = 0x20 , kUsesNonCoherentHWBlending = 0x40 , kUnaffectedByDstValue = 0x80 }

Public Member Functions
	GR_DECL_BITFIELD_CLASS_OPS_FRIENDS (AnalysisProperties)

Static Public Member Functions
static sk_sp< const GrXferProcessor >	MakeXferProcessor (const GrXPFactory *, const GrProcessorAnalysisColor &, GrProcessorAnalysisCoverage, const GrCaps &caps, GrClampType)
static AnalysisProperties	GetAnalysisProperties (const GrXPFactory *, const GrProcessorAnalysisColor &, const GrProcessorAnalysisCoverage &, const GrCaps &, GrClampType)
static const GrXPFactory *	FromBlendMode (SkBlendMode)

Protected Member Functions
constexpr	GrXPFactory ()

Private Member Functions
virtual sk_sp< const GrXferProcessor >	makeXferProcessor (const GrProcessorAnalysisColor &, GrProcessorAnalysisCoverage, const GrCaps &, GrClampType) const =0
virtual AnalysisProperties	analysisProperties (const GrProcessorAnalysisColor &, const GrProcessorAnalysisCoverage &, const GrCaps &, GrClampType) const =0

Detailed Description

We install a GrXPFactory (XPF) early on in the pipeline before all the final draw information is known (e.g. whether there is fractional pixel coverage, will coverage be 1 or 4 channel, is the draw opaque, etc.). Once the state of the draw is finalized, we use the XPF along with all the draw information to create a GrXferProcessor (XP) which can implement the desired blending for the draw.

Before the XP is created, the XPF is able to answer queries about what functionality the XPs it creates will have. For example, can it create an XP that supports RGB coverage or will the XP blend with the destination color.

GrXPFactories are intended to be static immutable objects. We pass them around as raw pointers and expect the pointers to always be valid and for the factories to be reusable and thread safe. Equality is tested for using pointer comparison. GrXPFactory destructors must be no-ops.

Definition at line 202 of file GrXferProcessor.h.

Member Enumeration Documentation

AnalysisProperties

enum class GrXPFactory::AnalysisProperties : unsigned

strong

Enumerator
kNone
kReadsDstInShader	The fragment shader will require the destination color.
kCompatibleWithCoverageAsAlpha	The op may apply coverage as alpha and still blend correctly.
kIgnoresInputColor	The color input to the GrXferProcessor will be ignored.
kRequiresDstTexture	The destination color will be provided to the fragment processor using a texture. This is additional information about the implementation of kReadsDstInShader.
kRequiresNonOverlappingDraws	If set, each pixel can only be touched once during a draw (e.g., because we have a dst texture or because we need an xfer barrier).
kUsesNonCoherentHWBlending	If set the draw will use fixed function non coherent advanced blends.
kUnaffectedByDstValue	If set, the existing dst value has no effect on the final output.

Definition at line 204 of file GrXferProcessor.h.

                                  : unsigned {
        kNone = 0x0,
        /**
         * The fragment shader will require the destination color.
         */
        kReadsDstInShader = 0x1,
        /**
         * The op may apply coverage as alpha and still blend correctly.
         */
        kCompatibleWithCoverageAsAlpha = 0x2,
        /**
         * The color input to the GrXferProcessor will be ignored.
         */
        kIgnoresInputColor = 0x4,
        /**
         * The destination color will be provided to the fragment processor using a texture. This is
         * additional information about the implementation of kReadsDstInShader.
         */
        kRequiresDstTexture = 0x10,
        /**
         * If set, each pixel can only be touched once during a draw (e.g., because we have a dst
         * texture or because we need an xfer barrier).
         */
        kRequiresNonOverlappingDraws = 0x20,
        /**
         * If set the draw will use fixed function non coherent advanced blends.
         */
        kUsesNonCoherentHWBlending = 0x40,
        /**
         * If set, the existing dst value has no effect on the final output.
         */
        kUnaffectedByDstValue = 0x80,
    };

Constructor & Destructor Documentation

GrXPFactory()

constexpr GrXPFactory::GrXPFactory ( )

inlineconstexprprotected

Definition at line 254 of file GrXferProcessor.h.

{}

Member Function Documentation

analysisProperties()

virtual AnalysisProperties GrXPFactory::analysisProperties ( const GrProcessorAnalysisColor &  , const GrProcessorAnalysisCoverage &  , const GrCaps &  , GrClampType    ) const

privatepure virtual

Subclass analysis implementation. This should not return kNeedsDstInTexture as that will be inferred by the base class based on kReadsDstInShader and the caps.

FromBlendMode()

const GrXPFactory * GrXPFactory::FromBlendMode ( SkBlendMode  mode )

static

Definition at line 102 of file GrXferProcessor.cpp.

                                                              {
    if (SkBlendMode_AsCoeff(mode, nullptr, nullptr)) {
        const GrXPFactory* result = GrPorterDuffXPFactory::Get(mode);
        SkASSERT(result);
        return result;
    }
 
    SkASSERT(GrCustomXfermode::IsSupportedMode(mode));
    return GrCustomXfermode::Get(mode);
}

GetAnalysisProperties()

GrXPFactory::AnalysisProperties GrXPFactory::GetAnalysisProperties ( const GrXPFactory *  factory, const GrProcessorAnalysisColor &  color, const GrProcessorAnalysisCoverage &  coverage, const GrCaps &  caps, GrClampType  clampType  )

static

Definition at line 66 of file GrXferProcessor.cpp.

                               {
    AnalysisProperties result;
    if (factory) {
        result = factory->analysisProperties(color, coverage, caps, clampType);
    } else {
        result = GrPorterDuffXPFactory::SrcOverAnalysisProperties(color, coverage, caps, clampType);
    }
    if (coverage == GrProcessorAnalysisCoverage::kNone) {
        result |= AnalysisProperties::kCompatibleWithCoverageAsAlpha;
    }
    SkASSERT(!(result & AnalysisProperties::kRequiresDstTexture));
    if ((result & AnalysisProperties::kReadsDstInShader) &&
        !caps.shaderCaps()->fDstReadInShaderSupport) {
        result |= AnalysisProperties::kRequiresDstTexture |
                  AnalysisProperties::kRequiresNonOverlappingDraws;
    }
    return result;
}

GR_DECL_BITFIELD_CLASS_OPS_FRIENDS()

GrXPFactory::GR_DECL_BITFIELD_CLASS_OPS_FRIENDS

(

AnalysisProperties

)

makeXferProcessor()

virtual sk_sp< const GrXferProcessor > GrXPFactory::makeXferProcessor ( const GrProcessorAnalysisColor &  , GrProcessorAnalysisCoverage  , const GrCaps &  , GrClampType    ) const

privatepure virtual

MakeXferProcessor()

sk_sp< const GrXferProcessor > GrXPFactory::MakeXferProcessor ( const GrXPFactory *  factory, const GrProcessorAnalysisColor &  color, GrProcessorAnalysisCoverage  coverage, const GrCaps &  caps, GrClampType  clampType  )

static

Definition at line 90 of file GrXferProcessor.cpp.

                                                                                   {
    if (factory) {
        return factory->makeXferProcessor(color, coverage, caps, clampType);
    } else {
        return GrPorterDuffXPFactory::MakeSrcOverXferProcessor(color, coverage, caps);
    }
}

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The documentation for this class was generated from the following files:

• third_party/skia/src/gpu/ganesh/GrXferProcessor.h
• third_party/skia/src/gpu/ganesh/GrXferProcessor.cpp