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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrPrimitiveProcessor_DEFINED
#define GrPrimitiveProcessor_DEFINED
#include "GrColor.h"
#include "GrNonAtomicRef.h"
#include "GrProcessor.h"
#include "GrProxyRef.h"
#include "GrShaderVar.h"
class GrCoordTransform;
/*
* The GrPrimitiveProcessor represents some kind of geometric primitive. This includes the shape
* of the primitive and the inherent color of the primitive. The GrPrimitiveProcessor is
* responsible for providing a color and coverage input into the Ganesh rendering pipeline. Through
* optimization, Ganesh may decide a different color, no color, and / or no coverage are required
* from the GrPrimitiveProcessor, so the GrPrimitiveProcessor must be able to support this
* functionality.
*
* There are two feedback loops between the GrFragmentProcessors, the GrXferProcessor, and the
* GrPrimitiveProcessor. These loops run on the CPU and to determine known properties of the final
* color and coverage inputs to the GrXferProcessor in order to perform optimizations that preserve
* correctness. The GrDrawOp seeds these loops with initial color and coverage, in its
* getProcessorAnalysisInputs implementation. These seed values are processed by the
* subsequent
* stages of the rendering pipeline and the output is then fed back into the GrDrawOp in
* the applyPipelineOptimizations call, where the op can use the information to inform decisions
* about GrPrimitiveProcessor creation.
*/
class GrGLSLPrimitiveProcessor;
/**
* GrPrimitiveProcessor defines an interface which all subclasses must implement. All
* GrPrimitiveProcessors must proivide seed color and coverage for the Ganesh color / coverage
* pipelines, and they must provide some notion of equality
*
* TODO: This class does not really need to be ref counted. Instances should be allocated using
* GrOpFlushState's arena and destroyed when the arena is torn down.
*/
class GrPrimitiveProcessor : public GrProcessor, public GrNonAtomicRef<GrPrimitiveProcessor> {
public:
class TextureSampler;
/** Describes a vertex or instance attribute. */
class Attribute {
public:
constexpr Attribute() = default;
constexpr Attribute(const char* name, GrVertexAttribType type) : fName(name), fType(type) {}
constexpr Attribute(const Attribute&) = default;
Attribute& operator=(const Attribute&) = default;
constexpr bool isInitialized() const { return SkToBool(fName); }
constexpr const char* name() const { return fName; }
constexpr GrVertexAttribType type() const { return fType; }
inline constexpr size_t size() const;
constexpr size_t sizeAlign4() const { return SkAlign4(this->size()); }
GrShaderVar asShaderVar() const {
return {fName, GrVertexAttribTypeToSLType(fType), GrShaderVar::kIn_TypeModifier};
}
private:
const char* fName = nullptr;
GrVertexAttribType fType = kFloat_GrVertexAttribType;
};
GrPrimitiveProcessor(ClassID);
int numTextureSamplers() const { return fTextureSamplerCnt; }
const TextureSampler& textureSampler(int index) const;
int numVertexAttributes() const { return fVertexAttributeCnt; }
const Attribute& vertexAttribute(int i) const;
int numInstanceAttributes() const { return fInstanceAttributeCnt; }
const Attribute& instanceAttribute(int i) const;
bool hasVertexAttributes() const { return SkToBool(fVertexAttributeCnt); }
bool hasInstanceAttributes() const { return SkToBool(fInstanceAttributeCnt); }
#ifdef SK_DEBUG
/**
* A common practice is to populate the the vertex/instance's memory using an implicit array of
* structs. In this case, it is best to assert that:
* debugOnly_stride == sizeof(struct) and
* offsetof(struct, field[i]) == debugOnly_AttributeOffset(i)
* In general having Op subclasses assert that attribute offsets and strides agree with their
* tessellation code's expectations is good practice.
* However, these functions walk the attributes to compute offsets and call virtual functions
* to access the attributes. Thus, they are only available in debug builds.
*/
size_t debugOnly_vertexStride() const;
size_t debugOnly_instanceStride() const;
size_t debugOnly_vertexAttributeOffset(int) const;
size_t debugOnly_instanceAttributeOffset(int) const;
#endif
// Only the GrGeometryProcessor subclass actually has a geo shader or vertex attributes, but
// we put these calls on the base class to prevent having to cast
virtual bool willUseGeoShader() const = 0;
/**
* Computes a transformKey from an array of coord transforms. Will only look at the first
* <numCoords> transforms in the array.
*
* TODO: A better name for this function would be "compute" instead of "get".
*/
uint32_t getTransformKey(const SkTArray<const GrCoordTransform*, true>& coords,
int numCoords) const;
/**
* Sets a unique key on the GrProcessorKeyBuilder that is directly associated with this geometry
* processor's GL backend implementation.
*
* TODO: A better name for this function would be "compute" instead of "get".
*/
virtual void getGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const = 0;
/** Returns a new instance of the appropriate *GL* implementation class
for the given GrProcessor; caller is responsible for deleting
the object. */
virtual GrGLSLPrimitiveProcessor* createGLSLInstance(const GrShaderCaps&) const = 0;
virtual bool isPathRendering() const { return false; }
/**
* If non-null, overrides the dest color returned by GrGLSLFragmentShaderBuilder::dstColor().
*/
virtual const char* getDestColorOverride() const { return nullptr; }
virtual float getSampleShading() const { return 0.0; }
protected:
void setVertexAttributeCnt(int cnt) {
SkASSERT(cnt >= 0);
fVertexAttributeCnt = cnt;
}
void setInstanceAttributeCnt(int cnt) {
SkASSERT(cnt >= 0);
fInstanceAttributeCnt = cnt;
}
void setTextureSamplerCnt(int cnt) {
SkASSERT(cnt >= 0);
fTextureSamplerCnt = cnt;
}
/**
* Helper for implementing onTextureSampler(). E.g.:
* return IthTexureSampler(i, fMyFirstSampler, fMySecondSampler, fMyThirdSampler);
*/
template <typename... Args>
static const TextureSampler& IthTextureSampler(int i, const TextureSampler& samp0,
const Args&... samps) {
return (0 == i) ? samp0 : IthTextureSampler(i - 1, samps...);
}
inline static const TextureSampler& IthTextureSampler(int i);
private:
virtual const Attribute& onVertexAttribute(int) const = 0;
virtual const Attribute& onInstanceAttribute(int) const = 0;
virtual const TextureSampler& onTextureSampler(int) const { return IthTextureSampler(0); }
int fVertexAttributeCnt = 0;
int fInstanceAttributeCnt = 0;
int fTextureSamplerCnt = 0;
typedef GrProcessor INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
/**
* Used to represent a texture that is required by a GrPrimitiveProcessor. It holds a GrTextureProxy
* along with an associated GrSamplerState. TextureSamplers don't perform any coord manipulation to
* account for texture origin.
*/
class GrPrimitiveProcessor::TextureSampler {
public:
TextureSampler() = default;
TextureSampler(GrTextureType, GrPixelConfig, const GrSamplerState&, GrShaderFlags visibility);
explicit TextureSampler(GrTextureType, GrPixelConfig,
GrSamplerState::Filter = GrSamplerState::Filter::kNearest,
GrSamplerState::WrapMode wrapXAndY = GrSamplerState::WrapMode::kClamp,
GrShaderFlags visibility = kFragment_GrShaderFlag);
TextureSampler(const TextureSampler&) = delete;
TextureSampler& operator=(const TextureSampler&) = delete;
void reset(GrTextureType, GrPixelConfig, const GrSamplerState&,
GrShaderFlags visibility = kFragment_GrShaderFlag);
void reset(GrTextureType, GrPixelConfig,
GrSamplerState::Filter = GrSamplerState::Filter::kNearest,
GrSamplerState::WrapMode wrapXAndY = GrSamplerState::WrapMode::kClamp,
GrShaderFlags visibility = kFragment_GrShaderFlag);
GrTextureType textureType() const { return fTextureType; }
GrPixelConfig config() const { return fConfig; }
GrShaderFlags visibility() const { return fVisibility; }
const GrSamplerState& samplerState() const { return fSamplerState; }
bool isInitialized() const { return fConfig != kUnknown_GrPixelConfig; }
private:
GrSamplerState fSamplerState;
GrTextureType fTextureType = GrTextureType::k2D;
GrPixelConfig fConfig = kUnknown_GrPixelConfig;
GrShaderFlags fVisibility = kNone_GrShaderFlags;
};
const GrPrimitiveProcessor::TextureSampler& GrPrimitiveProcessor::IthTextureSampler(int i) {
SK_ABORT("Illegal texture sampler index");
static const TextureSampler kBogus;
return kBogus;
}
//////////////////////////////////////////////////////////////////////////////
/**
* Returns the size of the attrib type in bytes.
* This was moved from include/private/GrTypesPriv.h in service of Skia dependents that build
* with C++11.
*/
static constexpr inline size_t GrVertexAttribTypeSize(GrVertexAttribType type) {
switch (type) {
case kFloat_GrVertexAttribType:
return sizeof(float);
case kFloat2_GrVertexAttribType:
return 2 * sizeof(float);
case kFloat3_GrVertexAttribType:
return 3 * sizeof(float);
case kFloat4_GrVertexAttribType:
return 4 * sizeof(float);
case kHalf_GrVertexAttribType:
return sizeof(float);
case kHalf2_GrVertexAttribType:
return 2 * sizeof(float);
case kHalf3_GrVertexAttribType:
return 3 * sizeof(float);
case kHalf4_GrVertexAttribType:
return 4 * sizeof(float);
case kInt2_GrVertexAttribType:
return 2 * sizeof(int32_t);
case kInt3_GrVertexAttribType:
return 3 * sizeof(int32_t);
case kInt4_GrVertexAttribType:
return 4 * sizeof(int32_t);
case kByte_GrVertexAttribType:
return 1 * sizeof(char);
case kByte2_GrVertexAttribType:
return 2 * sizeof(char);
case kByte3_GrVertexAttribType:
return 3 * sizeof(char);
case kByte4_GrVertexAttribType:
return 4 * sizeof(char);
case kUByte_GrVertexAttribType:
return 1 * sizeof(char);
case kUByte2_GrVertexAttribType:
return 2 * sizeof(char);
case kUByte3_GrVertexAttribType:
return 3 * sizeof(char);
case kUByte4_GrVertexAttribType:
return 4 * sizeof(char);
case kUByte_norm_GrVertexAttribType:
return 1 * sizeof(char);
case kUByte4_norm_GrVertexAttribType:
return 4 * sizeof(char);
case kShort2_GrVertexAttribType:
return 2 * sizeof(int16_t);
case kUShort2_GrVertexAttribType: // fall through
case kUShort2_norm_GrVertexAttribType:
return 2 * sizeof(uint16_t);
case kInt_GrVertexAttribType:
return sizeof(int32_t);
case kUint_GrVertexAttribType:
return sizeof(uint32_t);
}
// GCC fails because SK_ABORT evaluates to non constexpr. clang and cl.exe think this is
// unreachable and don't complain.
#if defined(__clang__) || !defined(__GNUC__)
SK_ABORT("Unsupported type conversion");
#endif
return 0;
}
constexpr size_t GrPrimitiveProcessor::Attribute::size() const {
return GrVertexAttribTypeSize(fType);
}
#endif