gecko/gfx/skia/include/gpu/GrDrawEffect.h
2013-04-02 16:49:07 -04:00

52 lines
2.1 KiB
C++

#ifndef GrDrawEffect_DEFINED
#define GrDrawEffect_DEFINED
#include "GrEffectStage.h"
/**
* This class is used to communicate the particular GrEffect used in a draw to the backend-specific
* effect subclass (e.g. GrGLEffect). It is used to by the backend-specific class to generate a
* cache key for the effect, generate code on a program cache miss, and to upload uniform values to
* the program.
* In addition to the effect, it also communicates any changes between the relationship between
* the view matrix and local coordinate system since the effect was installed in its GrDrawState.
* The typical use case is that sometime after an effect was installed a decision was made to draw
* in device coordinates (i.e. use an identity view-matrix). In such a case the GrDrawEffect's
* coord-change-matrix would be the inverse of the view matrix that was set when the effect was
* installed. GrGLEffectMatrix is a handy class that implements a local coordinate matrix that
* automatically accounts for the coord-change matrix.
*/
class GrDrawEffect {
public:
GrDrawEffect(const GrEffectStage& stage, bool explicitLocalCoords)
: fEffectStage(&stage)
, fExplicitLocalCoords(explicitLocalCoords) {
GrAssert(NULL != fEffectStage);
GrAssert(NULL != fEffectStage->getEffect());
}
const GrEffectRef* effect() const { return fEffectStage->getEffect(); }
template <typename T>
const T& castEffect() const { return *static_cast<const T*>(this->effect()->get()); }
const SkMatrix& getCoordChangeMatrix() const {
if (fExplicitLocalCoords) {
return SkMatrix::I();
} else {
return fEffectStage->getCoordChangeMatrix();
}
}
bool programHasExplicitLocalCoords() const { return fExplicitLocalCoords; }
const int* getVertexAttribIndices() const { return fEffectStage->getVertexAttribIndices(); }
int getVertexAttribIndexCount() const { return fEffectStage->getVertexAttribIndexCount(); }
private:
const GrEffectStage* fEffectStage;
bool fExplicitLocalCoords;
};
#endif