blob: 957ccecab802d83b0dc7f5188a95f5f2c090001e [file] [log] [blame]
/*
* 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 GrGLSLGeometryProcessor_DEFINED
#define GrGLSLGeometryProcessor_DEFINED
#include "src/gpu/GrFragmentProcessor.h"
#include "src/gpu/GrGeometryProcessor.h"
#include "src/gpu/GrShaderCaps.h"
#include "src/gpu/glsl/GrGLSLProgramDataManager.h"
#include "src/gpu/glsl/GrGLSLUniformHandler.h"
class GrGeometryProcessor;
class GrGLSLFPFragmentBuilder;
class GrGLSLGeometryBuilder;
class GrGLSLGPBuilder;
class GrGLSLVaryingHandler;
class GrGLSLVertexBuilder;
class GrShaderCaps;
/**
* GrGeometryProcessor-derived classes that need to emit GLSL vertex shader code should be paired
* with a sibling class derived from GrGLSLGeometryProcessor (and return an instance of it from
* createGLSLInstance).
*/
class GrGLSLGeometryProcessor {
public:
using UniformHandle = GrGLSLProgramDataManager::UniformHandle;
using SamplerHandle = GrGLSLUniformHandler::SamplerHandle;
virtual ~GrGLSLGeometryProcessor() {}
/**
* This class provides access to each GrFragmentProcessor in a GrPipeline that requires varying
* local coords to be produced by the primitive processor. It is also used by the primitive
* processor to specify the fragment shader variable that will hold the transformed coords for
* each of those GrFragmentProcessors. It is required that the primitive processor iterate over
* each fragment processor and insert a shader var result for each. The GrGLSLFragmentProcessors
* will reference these variables in their fragment code.
*/
class FPCoordTransformHandler : public SkNoncopyable {
public:
FPCoordTransformHandler(const GrPipeline&, SkTArray<GrShaderVar>*);
~FPCoordTransformHandler() { SkASSERT(!fIter); }
operator bool() const { return (bool)fIter; }
// Gets the current GrFragmentProcessor
const GrFragmentProcessor& get() const;
FPCoordTransformHandler& operator++();
void specifyCoordsForCurrCoordTransform(GrShaderVar varyingVar) {
SkASSERT(!fAddedCoord);
fTransformedCoordVars->push_back(varyingVar);
SkDEBUGCODE(fAddedCoord = true;)
}
private:
GrFragmentProcessor::CIter fIter;
SkDEBUGCODE(bool fAddedCoord = false;)
SkTArray<GrShaderVar>* fTransformedCoordVars;
};
struct EmitArgs {
EmitArgs(GrGLSLVertexBuilder* vertBuilder,
GrGLSLGeometryBuilder* geomBuilder,
GrGLSLFPFragmentBuilder* fragBuilder,
GrGLSLVaryingHandler* varyingHandler,
GrGLSLUniformHandler* uniformHandler,
const GrShaderCaps* caps,
const GrGeometryProcessor& geomProc,
const char* outputColor,
const char* outputCoverage,
const SamplerHandle* texSamplers,
FPCoordTransformHandler* transformHandler)
: fVertBuilder(vertBuilder)
, fGeomBuilder(geomBuilder)
, fFragBuilder(fragBuilder)
, fVaryingHandler(varyingHandler)
, fUniformHandler(uniformHandler)
, fShaderCaps(caps)
, fGeomProc(geomProc)
, fOutputColor(outputColor)
, fOutputCoverage(outputCoverage)
, fTexSamplers(texSamplers)
, fFPCoordTransformHandler(transformHandler) {}
GrGLSLVertexBuilder* fVertBuilder;
GrGLSLGeometryBuilder* fGeomBuilder;
GrGLSLFPFragmentBuilder* fFragBuilder;
GrGLSLVaryingHandler* fVaryingHandler;
GrGLSLUniformHandler* fUniformHandler;
const GrShaderCaps* fShaderCaps;
const GrGeometryProcessor& fGeomProc;
const char* fOutputColor;
const char* fOutputCoverage;
const SamplerHandle* fTexSamplers;
FPCoordTransformHandler* fFPCoordTransformHandler;
};
/* Any general emit code goes in the base class emitCode. Subclasses override onEmitCode */
void emitCode(EmitArgs&);
/**
* Called after all effect emitCode() functions, to give the processor a chance to write out
* additional transformation code now that all uniforms have been emitted.
* It generates the final code for assigning transformed coordinates to the varyings recorded
* in the call to collectTransforms(). This must happen after FP code emission so that it has
* access to any uniforms the FPs registered for uniform sample matrix invocations.
*/
void emitTransformCode(GrGLSLVertexBuilder* vb,
GrGLSLUniformHandler* uniformHandler);
/**
* A GrGLSLGeometryProcessor instance can be reused with any GrGLSLGeometryProcessor that
* produces the same stage key; this function reads data from a GrGLSLGeometryProcessor and
* uploads any uniform variables required by the shaders created in emitCode(). The
* GrGeometryProcessor parameter is guaranteed to be of the same type and to have an
* identical processor key as the GrGeometryProcessor that created this
* GrGLSLGeometryProcessor.
* The subclass should use the transform range to perform any setup required for the coord
* transforms of the FPs that are part of the same program, such as updating matrix uniforms.
* The range will iterate over the transforms in the same order as the TransformHandler passed
* to emitCode.
*/
virtual void setData(const GrGLSLProgramDataManager&,
const GrShaderCaps&,
const GrGeometryProcessor&) = 0;
// We use these methods as a temporary back door to inject OpenGL tessellation code. Once
// tessellation is supported by SkSL we can remove these.
virtual SkString getTessControlShaderGLSL(const GrGeometryProcessor&,
const char* versionAndExtensionDecls,
const GrGLSLUniformHandler&,
const GrShaderCaps&) const {
SK_ABORT("Not implemented.");
}
virtual SkString getTessEvaluationShaderGLSL(const GrGeometryProcessor&,
const char* versionAndExtensionDecls,
const GrGLSLUniformHandler&,
const GrShaderCaps&) const {
SK_ABORT("Not implemented.");
}
protected:
void setupUniformColor(GrGLSLFPFragmentBuilder* fragBuilder,
GrGLSLUniformHandler* uniformHandler,
const char* outputName,
UniformHandle* colorUniform);
// A helper for setting the matrix on a uniform handle initialized through
// writeOutputPosition or writeLocalCoord. Automatically handles elided uniforms,
// scale+translate matrices, and state tracking (if provided state pointer is non-null).
static void SetTransform(const GrGLSLProgramDataManager&,
const GrShaderCaps&,
const UniformHandle& uniform,
const SkMatrix& matrix,
SkMatrix* state = nullptr);
struct GrGPArgs {
// Used to specify the output variable used by the GP to store its device position. It can
// either be a float2 or a float3 (in order to handle perspective). The subclass sets this
// in its onEmitCode().
GrShaderVar fPositionVar;
// Used to specify the variable storing the draw's local coordinates. It can be either a
// float2, float3, or void. It can only be void when no FP needs local coordinates. This
// variable can be an attribute or local variable, but should not itself be a varying.
// GrGLSLGeometryProcessor automatically determines if this must be passed to a FS.
GrShaderVar fLocalCoordVar;
};
// Helpers for adding code to write the transformed vertex position. The first simple version
// just writes a variable named by 'posName' into the position output variable with the
// assumption that the position is 2D. The second version transforms the input position by a
// view matrix and the output variable is 2D or 3D depending on whether the view matrix is
// perspective. Both versions declare the output position variable and will set
// GrGPArgs::fPositionVar.
static void WriteOutputPosition(GrGLSLVertexBuilder*, GrGPArgs*, const char* posName);
static void WriteOutputPosition(GrGLSLVertexBuilder*,
GrGLSLUniformHandler*,
const GrShaderCaps&,
GrGPArgs*,
const char* posName,
const SkMatrix& viewMatrix,
UniformHandle* viewMatrixUniform);
// Helper to transform an existing variable by a given local matrix (e.g. the inverse view
// matrix). It will declare the transformed local coord variable and will set
// GrGPArgs::fLocalCoordVar.
static void WriteLocalCoord(GrGLSLVertexBuilder*,
GrGLSLUniformHandler*,
const GrShaderCaps&,
GrGPArgs*,
GrShaderVar localVar,
const SkMatrix& localMatrix,
UniformHandle* localMatrixUniform);
// GPs that use writeOutputPosition and/or writeLocalCoord must incorporate the matrix type
// into their key, and should use this function or one of the other related helpers.
static uint32_t ComputeMatrixKey(const GrShaderCaps& caps, const SkMatrix& mat) {
if (!caps.reducedShaderMode()) {
if (mat.isIdentity()) {
return 0b00;
}
if (mat.isScaleTranslate()) {
return 0b01;
}
}
if (!mat.hasPerspective()) {
return 0b10;
}
return 0b11;
}
static uint32_t ComputeMatrixKeys(const GrShaderCaps& shaderCaps,
const SkMatrix& viewMatrix,
const SkMatrix& localMatrix) {
return (ComputeMatrixKey(shaderCaps, viewMatrix) << kMatrixKeyBits) |
ComputeMatrixKey(shaderCaps, localMatrix);
}
static uint32_t AddMatrixKeys(const GrShaderCaps& shaderCaps,
uint32_t flags,
const SkMatrix& viewMatrix,
const SkMatrix& localMatrix) {
// Shifting to make room for the matrix keys shouldn't lose bits
SkASSERT(((flags << (2 * kMatrixKeyBits)) >> (2 * kMatrixKeyBits)) == flags);
return (flags << (2 * kMatrixKeyBits)) |
ComputeMatrixKeys(shaderCaps, viewMatrix, localMatrix);
}
static constexpr int kMatrixKeyBits = 2;
private:
virtual void onEmitCode(EmitArgs&, GrGPArgs*) = 0;
// Iterates over the FPs in 'handler' to register additional varyings and uniforms to support
// VS-promoted local coord evaluation for the FPs. Subclasses must call this with
// 'localCoordsVar' set to an SkSL variable expression of type 'float2' or 'float3' representing
// the original local coordinates of the draw.
//
// This must happen before FP code emission so that the FPs can find the appropriate varying
// handles they use in place of explicit coord sampling; it is automatically called after
// onEmitCode() returns using the value stored in GpArgs::fLocalCoordVar.
void collectTransforms(GrGLSLVertexBuilder* vb,
GrGLSLVaryingHandler* varyingHandler,
GrGLSLUniformHandler* uniformHandler,
const GrShaderVar& localCoordsVar,
FPCoordTransformHandler* handler);
struct TransformInfo {
// The vertex-shader output variable to assign the transformed coordinates to
GrShaderVar fOutputCoords;
// The coordinate to be transformed
GrShaderVar fLocalCoords;
// The leaf FP of a transform hierarchy to be evaluated in the vertex shader;
// this FP will be const-uniform sampled, and all of its parents will have a sample matrix
// type of none or const-uniform.
const GrFragmentProcessor* fFP;
};
SkTArray<TransformInfo> fTransformInfos;
};
#endif