1
2#ifndef GrDrawEffect_DEFINED
3#define GrDrawEffect_DEFINED
4
5#include "GrEffectStage.h"
6
7/**
8 * This class is used to communicate the particular GrEffect used in a draw to the backend-specific
9 * effect subclass (e.g. GrGLEffect). It is used to by the backend-specific class to generate a
10 * cache key for the effect, generate code on a program cache miss, and to upload uniform values to
11 * the program.
12 * In addition to the effect, it also communicates any changes between the relationship between
13 * the view matrix and local coordinate system since the effect was installed in its GrDrawState.
14 * The typical use case is that sometime after an effect was installed a decision was made to draw
15 * in device coordinates (i.e. use an identity view-matrix). In such a case the GrDrawEffect's
16 * coord-change-matrix would be the inverse of the view matrix that was set when the effect was
17 * installed.
18 */
19class GrDrawEffect {
20public:
21    GrDrawEffect(const GrEffectStage& stage, bool explicitLocalCoords)
22        : fEffectStage(&stage)
23        , fExplicitLocalCoords(explicitLocalCoords) {
24        SkASSERT(NULL != fEffectStage);
25        SkASSERT(NULL != fEffectStage->getEffect());
26    }
27    const GrEffectRef* effect() const { return fEffectStage->getEffect(); }
28
29    template <typename T>
30    const T& castEffect() const { return *static_cast<const T*>(this->effect()->get()); }
31
32    const SkMatrix& getCoordChangeMatrix() const {
33        if (fExplicitLocalCoords) {
34            return SkMatrix::I();
35        } else {
36            return fEffectStage->getCoordChangeMatrix();
37        }
38    }
39
40    bool programHasExplicitLocalCoords() const { return fExplicitLocalCoords; }
41
42    const int* getVertexAttribIndices() const { return fEffectStage->getVertexAttribIndices(); }
43    int getVertexAttribIndexCount() const { return fEffectStage->getVertexAttribIndexCount(); }
44
45private:
46    const GrEffectStage*    fEffectStage;
47    bool                    fExplicitLocalCoords;
48};
49
50#endif
51