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 GrTBackendEffectFactory_DEFINED
michael@0: #define GrTBackendEffectFactory_DEFINED
michael@0: 
michael@0: #include "GrBackendEffectFactory.h"
michael@0: #include "GrDrawEffect.h"
michael@0: #include "gl/GrGLProgramEffects.h"
michael@0: 
michael@0: /**
michael@0:  * Implements GrBackendEffectFactory for a GrEffect subclass as a singleton.
michael@0:  */
michael@0: template <typename EffectClass>
michael@0: class GrTBackendEffectFactory : public GrBackendEffectFactory {
michael@0: 
michael@0: public:
michael@0:     typedef typename EffectClass::GLEffect GLEffect;
michael@0: 
michael@0:     /** Returns a human-readable name that is accessible via GrEffect or
michael@0:         GrGLEffect and is consistent between the two of them.
michael@0:      */
michael@0:     virtual const char* name() const SK_OVERRIDE { return EffectClass::Name(); }
michael@0: 
michael@0:     /** Returns a value that identifies the GLSL shader code generated by
michael@0:         a GrEffect. This enables caching of generated shaders. Part of the
michael@0:         id identifies the GrEffect subclass. The remainder is based
michael@0:         on the aspects of the GrEffect object's configuration that affect
michael@0:         GLSL code generation. */
michael@0:     virtual EffectKey glEffectKey(const GrDrawEffect& drawEffect,
michael@0:                                   const GrGLCaps& caps) const SK_OVERRIDE {
michael@0:         SkASSERT(kIllegalEffectClassID != fEffectClassID);
michael@0:         EffectKey effectKey = GLEffect::GenKey(drawEffect, caps);
michael@0:         EffectKey textureKey = GrGLProgramEffects::GenTextureKey(drawEffect, caps);
michael@0:         EffectKey transformKey = GrGLProgramEffects::GenTransformKey(drawEffect);
michael@0:         EffectKey attribKey = GrGLProgramEffects::GenAttribKey(drawEffect);
michael@0: #ifdef SK_DEBUG
michael@0:         static const EffectKey kIllegalEffectKeyMask = (uint16_t) (~((1U << kEffectKeyBits) - 1));
michael@0:         SkASSERT(!(kIllegalEffectKeyMask & effectKey));
michael@0: 
michael@0:         static const EffectKey kIllegalTextureKeyMask = (uint16_t) (~((1U << kTextureKeyBits) - 1));
michael@0:         SkASSERT(!(kIllegalTextureKeyMask & textureKey));
michael@0: 
michael@0:         static const EffectKey kIllegalTransformKeyMask = (uint16_t) (~((1U << kTransformKeyBits) - 1));
michael@0:         SkASSERT(!(kIllegalTransformKeyMask & transformKey));
michael@0: 
michael@0:         static const EffectKey kIllegalAttribKeyMask = (uint16_t) (~((1U << kAttribKeyBits) - 1));
michael@0:         SkASSERT(!(kIllegalAttribKeyMask & textureKey));
michael@0: 
michael@0:         static const EffectKey kIllegalClassIDMask = (uint16_t) (~((1U << kClassIDBits) - 1));
michael@0:         SkASSERT(!(kIllegalClassIDMask & fEffectClassID));
michael@0: #endif
michael@0:         return (fEffectClassID << (kEffectKeyBits+kTextureKeyBits+kTransformKeyBits+kAttribKeyBits)) |
michael@0:                (attribKey << (kEffectKeyBits+kTextureKeyBits+kTransformKeyBits)) |
michael@0:                (transformKey << (kEffectKeyBits+kTextureKeyBits)) |
michael@0:                (textureKey << kEffectKeyBits) |
michael@0:                (effectKey);
michael@0:     }
michael@0: 
michael@0:     /** Returns a new instance of the appropriate *GL* implementation class
michael@0:         for the given GrEffect; caller is responsible for deleting
michael@0:         the object. */
michael@0:     virtual GrGLEffect* createGLInstance(const GrDrawEffect& drawEffect) const SK_OVERRIDE {
michael@0:         return SkNEW_ARGS(GLEffect, (*this, drawEffect));
michael@0:     }
michael@0: 
michael@0:     /** This class is a singleton. This function returns the single instance.
michael@0:      */
michael@0:     static const GrBackendEffectFactory& getInstance() {
michael@0:         static SkAlignedSTStorage<1, GrTBackendEffectFactory> gInstanceMem;
michael@0:         static const GrTBackendEffectFactory* gInstance;
michael@0:         if (!gInstance) {
michael@0:             gInstance = SkNEW_PLACEMENT(gInstanceMem.get(),
michael@0:                                         GrTBackendEffectFactory);
michael@0:         }
michael@0:         return *gInstance;
michael@0:     }
michael@0: 
michael@0: protected:
michael@0:     GrTBackendEffectFactory() {
michael@0:         fEffectClassID = GenID();
michael@0:     }
michael@0: };
michael@0: 
michael@0: #endif