blob: 28114436de9b8a1bbf7210be340896eaad14eb9c [file] [log] [blame]
* 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 GrBackendEffectFactory_DEFINED
#define GrBackendEffectFactory_DEFINED
#include "GrTypes.h"
#include "SkTemplates.h"
#include "SkThread_platform.h"
#include "GrNoncopyable.h"
/** Given a GrEffect of a particular type, creates the corresponding graphics-backend-specific
effect object. Also tracks equivalence of shaders generated via a key. Each factory instance
is assigned a generation ID at construction. The ID of the return of GrEffect::getFactory()
is used as a type identifier. Thus a GrEffect subclass must return a singleton from
getFactory(). GrEffect subclasses should use the derived class GrTBackendEffectFactory that is
templated on the GrEffect subclass as their factory object. It requires that the GrEffect
subclass has a nested class (or typedef) GLEffect which is its GL implementation and a subclass
of GrGLEffect.
class GrEffectRef;
class GrGLEffect;
class GrGLCaps;
class GrDrawEffect;
class GrBackendEffectFactory : public GrNoncopyable {
typedef uint32_t EffectKey;
enum {
kNoEffectKey = 0,
kEffectKeyBits = 15,
* Some aspects of the generated code may be determined by the particular textures that are
* associated with the effect. These manipulations are performed by GrGLShaderBuilder beyond
* GrGLEffects' control. So there is a dedicated part of the key which is combined
* automatically with the bits produced by GrGLEffect::GenKey().
kTextureKeyBits = 6,
kAttribKeyBits = 6
virtual EffectKey glEffectKey(const GrDrawEffect&, const GrGLCaps&) const = 0;
virtual GrGLEffect* createGLInstance(const GrDrawEffect&) const = 0;
bool operator ==(const GrBackendEffectFactory& b) const {
return fEffectClassID == b.fEffectClassID;
bool operator !=(const GrBackendEffectFactory& b) const {
return !(*this == b);
virtual const char* name() const = 0;
enum {
kIllegalEffectClassID = 0,
GrBackendEffectFactory() {
fEffectClassID = kIllegalEffectClassID;
virtual ~GrBackendEffectFactory() {}
static EffectKey GenID() {
GR_DEBUGCODE(static const int32_t kClassIDBits = 8 * sizeof(EffectKey) -
kTextureKeyBits - kEffectKeyBits - kAttribKeyBits);
// fCurrEffectClassID has been initialized to kIllegalEffectClassID. The
// atomic inc returns the old value not the incremented value. So we add
// 1 to the returned value.
int32_t id = sk_atomic_inc(&fCurrEffectClassID) + 1;
GrAssert(id < (1 << kClassIDBits));
return static_cast<EffectKey>(id);
EffectKey fEffectClassID;
static int32_t fCurrEffectClassID;