michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef GrSingleTextureEffect_DEFINED
michael@0: #define GrSingleTextureEffect_DEFINED
michael@0: 
michael@0: #include "GrEffect.h"
michael@0: #include "SkMatrix.h"
michael@0: #include "GrCoordTransform.h"
michael@0: 
michael@0: class GrTexture;
michael@0: 
michael@0: /**
michael@0:  * A base class for effects that draw a single texture with a texture matrix. This effect has no
michael@0:  * backend implementations. One must be provided by the subclass.
michael@0:  */
michael@0: class GrSingleTextureEffect : public GrEffect {
michael@0: public:
michael@0:     virtual ~GrSingleTextureEffect();
michael@0: 
michael@0: protected:
michael@0:     /** unfiltered, clamp mode */
michael@0:     GrSingleTextureEffect(GrTexture*, const SkMatrix&, GrCoordSet = kLocal_GrCoordSet);
michael@0:     /** clamp mode */
michael@0:     GrSingleTextureEffect(GrTexture*, const SkMatrix&, GrTextureParams::FilterMode filterMode,
michael@0:                           GrCoordSet = kLocal_GrCoordSet);
michael@0:     GrSingleTextureEffect(GrTexture*,
michael@0:                           const SkMatrix&,
michael@0:                           const GrTextureParams&,
michael@0:                           GrCoordSet = kLocal_GrCoordSet);
michael@0: 
michael@0:     /**
michael@0:      * Helper for subclass onIsEqual() functions.
michael@0:      */
michael@0:     bool hasSameTextureParamsMatrixAndSourceCoords(const GrSingleTextureEffect& other) const {
michael@0:         // We don't have to check the accesses' swizzles because they are inferred from the texture.
michael@0:         return fTextureAccess == other.fTextureAccess &&
michael@0:                fCoordTransform.getMatrix().cheapEqualTo(other.fCoordTransform.getMatrix()) &&
michael@0:                fCoordTransform.sourceCoords() == other.fCoordTransform.sourceCoords();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Can be used as a helper to implement subclass getConstantColorComponents(). It assumes that
michael@0:      * the subclass output color will be a modulation of the input color with a value read from the
michael@0:      * texture.
michael@0:      */
michael@0:     void updateConstantColorComponentsForModulation(GrColor* color, uint32_t* validFlags) const {
michael@0:         if ((*validFlags & kA_GrColorComponentFlag) && 0xFF == GrColorUnpackA(*color) &&
michael@0:             GrPixelConfigIsOpaque(this->texture(0)->config())) {
michael@0:             *validFlags = kA_GrColorComponentFlag;
michael@0:         } else {
michael@0:             *validFlags = 0;
michael@0:         }
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     GrCoordTransform fCoordTransform;
michael@0:     GrTextureAccess  fTextureAccess;
michael@0: 
michael@0:     typedef GrEffect INHERITED;
michael@0: };
michael@0: 
michael@0: #endif