Home | History | Annotate | Download | only in gpu 
      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. GrGLEffectMatrix is a handy class that implements a local coordinate matrix that
     18  * automatically accounts for the coord-change matrix.
     19  */
     20 class GrDrawEffect {
     21 public:
     22     GrDrawEffect(const GrEffectStage& stage, bool explicitLocalCoords)
     23         : fEffectStage(&stage)
     24         , fExplicitLocalCoords(explicitLocalCoords) {
     25         GrAssert(NULL != fEffectStage);
     26         GrAssert(NULL != fEffectStage->getEffect());
     27     }
     28     const GrEffectRef* effect() const { return fEffectStage->getEffect(); }
     29 
     30     template <typename T>
     31     const T& castEffect() const { return *static_cast<const T*>(this->effect()->get()); }
     32 
     33     const SkMatrix& getCoordChangeMatrix() const {
     34         if (fExplicitLocalCoords) {
     35             return SkMatrix::I();
     36         } else {
     37             return fEffectStage->getCoordChangeMatrix();
     38         }
     39     }
     40 
     41     bool programHasExplicitLocalCoords() const { return fExplicitLocalCoords; }
     42 
     43     const int* getVertexAttribIndices() const { return fEffectStage->getVertexAttribIndices(); }
     44     int getVertexAttribIndexCount() const { return fEffectStage->getVertexAttribIndexCount(); }
     45 
     46 private:
     47     const GrEffectStage*    fEffectStage;
     48     bool                    fExplicitLocalCoords;
     49 };
     50 
     51 #endif
     52