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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 GrGLSLGeometryProcessor_DEFINED
#define GrGLSLGeometryProcessor_DEFINED
#include "GrGLSLPrimitiveProcessor.h"
class GrGLSLGPBuilder;
* If a GL effect needs a GrGLFullShaderBuilder* object to emit vertex code, then it must inherit
* from this class. Since paths don't have vertices, this class is only meant to be used internally
* by skia, for special cases.
class GrGLSLGeometryProcessor : public GrGLSLPrimitiveProcessor {
/* Any general emit code goes in the base class emitCode. Subclasses override onEmitCode */
void emitCode(EmitArgs&) final;
// A helper which subclasses can use to upload coord transform matrices in setData().
void setTransformDataHelper(const SkMatrix& localMatrix,
const GrGLSLProgramDataManager& pdman,
// Emit transformed local coords from the vertex shader as a uniform matrix and varying per
// coord-transform. localCoordsVar must be a 2- or 3-component vector. If it is 3 then it is
// assumed to be a 2D homogeneous coordinate.
void emitTransforms(GrGLSLVertexBuilder*,
const GrShaderVar& localCoordsVar,
const SkMatrix& localMatrix,
// Version of above that assumes identity for the local matrix.
void emitTransforms(GrGLSLVertexBuilder* vb,
GrGLSLVaryingHandler* varyingHandler,
GrGLSLUniformHandler* uniformHandler,
const GrShaderVar& localCoordsVar,
FPCoordTransformHandler* handler) {
this->emitTransforms(vb, varyingHandler, uniformHandler, localCoordsVar, SkMatrix::I(),
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;
// 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.
void writeOutputPosition(GrGLSLVertexBuilder*, GrGPArgs*, const char* posName);
void writeOutputPosition(GrGLSLVertexBuilder*,
GrGLSLUniformHandler* uniformHandler,
const char* posName,
const SkMatrix& mat,
UniformHandle* viewMatrixUniform);
static uint32_t ComputePosKey(const SkMatrix& mat) {
if (mat.isIdentity()) {
return 0x0;
} else if (!mat.hasPerspective()) {
return 0x01;
} else {
return 0x02;
virtual void onEmitCode(EmitArgs&, GrGPArgs*) = 0;
struct TransformUniform {
UniformHandle fHandle;
SkMatrix fCurrentValue = SkMatrix::InvalidMatrix();
SkTArray<TransformUniform, true> fInstalledTransforms;
typedef GrGLSLPrimitiveProcessor INHERITED;