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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 GrGLGeometryProcessor_DEFINED
#define GrGLGeometryProcessor_DEFINED
#include "GrGLPrimitiveProcessor.h"
class GrGLGPBuilder;
/**
* 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 GrGLGeometryProcessor : public GrGLPrimitiveProcessor {
public:
/* Any general emit code goes in the base class emitCode. Subclasses override onEmitCode */
void emitCode(EmitArgs&) override;
// By default we use the identity matrix
void setTransformData(const GrPrimitiveProcessor&,
const GrGLProgramDataManager& pdman,
int index,
const SkTArray<const GrCoordTransform*, true>& transforms) override {
this->setTransformDataMatrix(SkMatrix::I(), pdman, index, transforms);
}
// A helper which subclasses can use if needed
template <class GeometryProcessor>
void setTransformDataHelper(const GrPrimitiveProcessor& primProc,
const GrGLProgramDataManager& pdman,
int index,
const SkTArray<const GrCoordTransform*, true>& transforms) {
const GeometryProcessor& gp = primProc.cast<GeometryProcessor>();
this->setTransformDataMatrix(gp.localMatrix(), pdman, index, transforms);
}
protected:
// Emit a uniform matrix for each coord transform.
void emitTransforms(GrGLGPBuilder* gp,
const GrShaderVar& posVar,
const char* localCoords,
const TransformsIn& tin,
TransformsOut* tout) {
this->emitTransforms(gp, posVar, localCoords, SkMatrix::I(), tin, tout);
}
// Emit pre-transformed coords as a vertex attribute per coord-transform.
void emitTransforms(GrGLGPBuilder*,
const GrShaderVar& posVar,
const char* localCoords,
const SkMatrix& localMatrix,
const TransformsIn&,
TransformsOut*);
// caller has emitted transforms via attributes
void emitTransforms(GrGLGPBuilder*,
const char* localCoords,
const TransformsIn& tin,
TransformsOut* tout);
struct GrGPArgs {
// The variable used by a GP to store its position. It can be
// either a vec2 or a vec3 depending on the presence of perspective.
GrShaderVar fPositionVar;
};
// Create the correct type of position variable given the CTM
void setupPosition(GrGLGPBuilder*, GrGPArgs*, const char* posName);
void setupPosition(GrGLGPBuilder*, GrGPArgs*, 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;
}
}
private:
void setTransformDataMatrix(const SkMatrix& localMatrix,
const GrGLProgramDataManager& pdman,
int index,
const SkTArray<const GrCoordTransform*, true>& transforms) {
SkSTArray<2, Transform, true>& procTransforms = fInstalledTransforms[index];
int numTransforms = transforms.count();
for (int t = 0; t < numTransforms; ++t) {
SkASSERT(procTransforms[t].fHandle.isValid());
const SkMatrix& transform = GetTransformMatrix(localMatrix, *transforms[t]);
if (!procTransforms[t].fCurrentValue.cheapEqualTo(transform)) {
pdman.setSkMatrix(procTransforms[t].fHandle.toIndex(), transform);
procTransforms[t].fCurrentValue = transform;
}
}
}
virtual void onEmitCode(EmitArgs&, GrGPArgs*) = 0;
typedef GrGLPrimitiveProcessor INHERITED;
};
#endif