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* Copyright 2012 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef GrTBackendEffectFactory_DEFINED
#define GrTBackendEffectFactory_DEFINED
#include "GrBackendEffectFactory.h"
#include "GrDrawEffect.h"
#include "gl/GrGLProgramEffects.h"
* Implements GrBackendEffectFactory for a GrEffect subclass as a singleton. This can be used by
* most GrEffect subclasses to implement the GrEffect::getFactory() method:
* const GrBackendEffectFactory& MyEffect::getFactory() const {
* return GrTBackendEffectFactory<MyEffect>::getInstance();
* }
* Using this class requires that the GrEffect subclass always produces the same GrGLEffect
* subclass. Additionally, It adds the following requirements to the GrEffect and GrGLEffect
* subclasses:
* 1. The GrGLEffect used by GrEffect subclass MyEffect must be named or typedef'ed to
* MyEffect::GLEffect.
* 2. MyEffect::GLEffect must have a static function:
* EffectKey GenKey(const GrDrawEffect, const GrGLCaps&)
* which generates a key that maps 1 to 1 with code variations emitted by
* MyEffect::GLEffect::emitCode().
* 3. MyEffect must have a static function:
* const char* Name()
* which returns a human-readable name for the effect.
template <typename EffectClass>
class GrTBackendEffectFactory : public GrBackendEffectFactory {
typedef typename EffectClass::GLEffect GLEffect;
/** Returns a human-readable name for the effect. Implemented using GLEffect::Name as described
* in this class's comment. */
virtual const char* name() const SK_OVERRIDE { return EffectClass::Name(); }
/** Implemented using GLEffect::GenKey as described in this class's comment. */
virtual void getGLEffectKey(const GrDrawEffect& drawEffect,
const GrGLCaps& caps,
GrEffectKeyBuilder* b) const SK_OVERRIDE {
GLEffect::GenKey(drawEffect, caps, b);
/** Returns a new instance of the appropriate *GL* implementation class
for the given GrEffect; caller is responsible for deleting
the object. */
virtual GrGLEffect* createGLInstance(const GrDrawEffect& drawEffect) const SK_OVERRIDE {
return SkNEW_ARGS(GLEffect, (*this, drawEffect));
/** This class is a singleton. This function returns the single instance. */
static const GrBackendEffectFactory& getInstance() {
static SkAlignedSTStorage<1, GrTBackendEffectFactory> gInstanceMem;
static const GrTBackendEffectFactory* gInstance;
if (!gInstance) {
gInstance = SkNEW_PLACEMENT(gInstanceMem.get(),
return *gInstance;
GrTBackendEffectFactory() {}