| /* |
| * 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 GrEffect_DEFINED |
| #define GrEffect_DEFINED |
| |
| #include "GrColor.h" |
| #include "GrEffectUnitTest.h" |
| #include "GrNoncopyable.h" |
| #include "GrRefCnt.h" |
| #include "GrTexture.h" |
| #include "GrTextureAccess.h" |
| #include "GrTypesPriv.h" |
| |
| class GrBackendEffectFactory; |
| class GrContext; |
| class GrEffect; |
| class SkString; |
| |
| /** |
| * A Wrapper class for GrEffect. Its ref-count will track owners that may use effects to enqueue |
| * new draw operations separately from ownership within a deferred drawing queue. When the |
| * GrEffectRef ref count reaches zero the scratch GrResources owned by the effect can be recycled |
| * in service of later draws. However, the deferred draw queue may still own direct references to |
| * the underlying GrEffect. |
| * |
| * GrEffectRefs created by new are placed in a per-thread managed pool. The pool is destroyed when |
| * the thread ends. Therefore, all dynamically allocated GrEffectRefs must be unreffed before thread |
| * termination. |
| */ |
| class GrEffectRef : public SkRefCnt { |
| public: |
| SK_DECLARE_INST_COUNT(GrEffectRef); |
| virtual ~GrEffectRef(); |
| |
| GrEffect* get() { return fEffect; } |
| const GrEffect* get() const { return fEffect; } |
| |
| const GrEffect* operator-> () { return fEffect; } |
| const GrEffect* operator-> () const { return fEffect; } |
| |
| void* operator new(size_t size); |
| void operator delete(void* target); |
| |
| void* operator new(size_t size, void* placement) { |
| return ::operator new(size, placement); |
| } |
| void operator delete(void* target, void* placement) { |
| ::operator delete(target, placement); |
| } |
| |
| private: |
| friend class GrEffect; // to construct these |
| |
| explicit GrEffectRef(GrEffect* effect); |
| |
| GrEffect* fEffect; |
| |
| typedef SkRefCnt INHERITED; |
| }; |
| |
| /** Provides custom vertex shader, fragment shader, uniform data for a particular stage of the |
| Ganesh shading pipeline. |
| Subclasses must have a function that produces a human-readable name: |
| static const char* Name(); |
| GrEffect objects *must* be immutable: after being constructed, their fields may not change. |
| |
| GrEffect subclass objects should be created by factory functions that return GrEffectRef. |
| There is no public way to wrap a GrEffect in a GrEffectRef. Thus, a factory should be a static |
| member function of a GrEffect subclass. |
| |
| Because almost no code should ever handle a GrEffect directly outside of a GrEffectRef, we |
| privately inherit from GrRefCnt to help prevent accidental direct ref'ing/unref'ing of effects. |
| |
| Dynamically allocated GrEffects and their corresponding GrEffectRefs are managed by a per-thread |
| memory pool. The ref count of an effect must reach 0 before the thread terminates and the pool |
| is destroyed. To create a static effect use the macro GR_CREATE_STATIC_EFFECT declared below. |
| */ |
| class GrEffect : private GrRefCnt { |
| public: |
| SK_DECLARE_INST_COUNT(GrEffect) |
| |
| /** |
| * The types of vertex coordinates available to an effect in the vertex shader. Effects can |
| * require their own vertex attribute but these coordinates are made available by the framework |
| * in all programs. kCustom_CoordsType is provided to signify that an alternative set of coords |
| * is used (usually an explicit vertex attribute) but its meaning is determined by the effect |
| * subclass. |
| */ |
| enum CoordsType { |
| kLocal_CoordsType, |
| kPosition_CoordsType, |
| |
| kCustom_CoordsType, |
| }; |
| |
| virtual ~GrEffect(); |
| |
| /** |
| * This function is used to perform optimizations. When called the color and validFlags params |
| * indicate whether the input components to this effect in the FS will have known values. |
| * validFlags is a bitfield of GrColorComponentFlags. The function updates both params to |
| * indicate known values of its output. A component of the color param only has meaning if the |
| * corresponding bit in validFlags is set. |
| */ |
| virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const = 0; |
| |
| /** This object, besides creating back-end-specific helper objects, is used for run-time-type- |
| identification. The factory should be an instance of templated class, |
| GrTBackendEffectFactory. It is templated on the subclass of GrEffect. The subclass must have |
| a nested type (or typedef) named GLEffect which will be the subclass of GrGLEffect created |
| by the factory. |
| |
| Example: |
| class MyCustomEffect : public GrEffect { |
| ... |
| virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE { |
| return GrTBackendEffectFactory<MyCustomEffect>::getInstance(); |
| } |
| ... |
| }; |
| */ |
| virtual const GrBackendEffectFactory& getFactory() const = 0; |
| |
| /** Returns true if this and other effect conservatively draw identically. It can only return |
| true when the two effects are of the same subclass (i.e. they return the same object from |
| from getFactory()). |
| |
| A return value of true from isEqual() should not be used to test whether the effects would |
| generate the same shader code. To test for identical code generation use the EffectKey |
| computed by the GrBackendEffectFactory: |
| effectA.getFactory().glEffectKey(effectA) == effectB.getFactory().glEffectKey(effectB). |
| */ |
| bool isEqual(const GrEffectRef& other) const { |
| return this->isEqual(*other.get()); |
| } |
| |
| /** Human-meaningful string to identify this effect; may be embedded |
| in generated shader code. */ |
| const char* name() const; |
| |
| int numTextures() const { return fTextureAccesses.count(); } |
| |
| /** Returns the access pattern for the texture at index. index must be valid according to |
| numTextures(). */ |
| const GrTextureAccess& textureAccess(int index) const { return *fTextureAccesses[index]; } |
| |
| /** Shortcut for textureAccess(index).texture(); */ |
| GrTexture* texture(int index) const { return this->textureAccess(index).getTexture(); } |
| |
| /** Will this effect read the destination pixel value? */ |
| bool willReadDstColor() const { return fWillReadDstColor; } |
| |
| /** Will this effect read the fragment position? */ |
| bool willReadFragmentPosition() const { return fWillReadFragmentPosition; } |
| |
| int numVertexAttribs() const { return fVertexAttribTypes.count(); } |
| |
| GrSLType vertexAttribType(int index) const { return fVertexAttribTypes[index]; } |
| |
| static const int kMaxVertexAttribs = 2; |
| |
| /** Useful for effects that want to insert a texture matrix that is implied by the texture |
| dimensions */ |
| static inline SkMatrix MakeDivByTextureWHMatrix(const GrTexture* texture) { |
| GrAssert(NULL != texture); |
| SkMatrix mat; |
| mat.setIDiv(texture->width(), texture->height()); |
| return mat; |
| } |
| |
| void* operator new(size_t size); |
| void operator delete(void* target); |
| |
| void* operator new(size_t size, void* placement) { |
| return ::operator new(size, placement); |
| } |
| void operator delete(void* target, void* placement) { |
| ::operator delete(target, placement); |
| } |
| |
| /** These functions are used when recording effects into a deferred drawing queue. The inc call |
| keeps the effect alive outside of GrEffectRef while allowing any resources owned by the |
| effect to be returned to the cache for reuse. The dec call must balance the inc call. */ |
| void incDeferredRefCounts() const { |
| this->ref(); |
| int count = fTextureAccesses.count(); |
| for (int t = 0; t < count; ++t) { |
| fTextureAccesses[t]->getTexture()->incDeferredRefCount(); |
| } |
| } |
| void decDeferredRefCounts() const { |
| int count = fTextureAccesses.count(); |
| for (int t = 0; t < count; ++t) { |
| fTextureAccesses[t]->getTexture()->decDeferredRefCount(); |
| } |
| this->unref(); |
| } |
| |
| protected: |
| /** |
| * Subclasses call this from their constructor to register GrTextureAccesses. The effect |
| * subclass manages the lifetime of the accesses (this function only stores a pointer). This |
| * must only be called from the constructor because GrEffects are immutable. |
| */ |
| void addTextureAccess(const GrTextureAccess* textureAccess); |
| |
| /** |
| * Subclasses call this from their constructor to register vertex attributes (at most |
| * kMaxVertexAttribs). This must only be called from the constructor because GrEffects are |
| * immutable. |
| */ |
| void addVertexAttrib(GrSLType type); |
| |
| GrEffect() : fWillReadDstColor(false), fWillReadFragmentPosition(false), fEffectRef(NULL) {} |
| |
| /** This should be called by GrEffect subclass factories. See the comment on AutoEffectUnref for |
| an example factory function. */ |
| static GrEffectRef* CreateEffectRef(GrEffect* effect) { |
| if (NULL == effect->fEffectRef) { |
| effect->fEffectRef = SkNEW_ARGS(GrEffectRef, (effect)); |
| } else { |
| effect->fEffectRef->ref(); |
| } |
| return effect->fEffectRef; |
| } |
| |
| static const GrEffectRef* CreateEffectRef(const GrEffect* effect) { |
| return CreateEffectRef(const_cast<GrEffect*>(effect)); |
| } |
| |
| /** Used by GR_CREATE_STATIC_EFFECT below */ |
| static GrEffectRef* CreateStaticEffectRef(void* refStorage, GrEffect* effect) { |
| GrAssert(NULL == effect->fEffectRef); |
| effect->fEffectRef = SkNEW_PLACEMENT_ARGS(refStorage, GrEffectRef, (effect)); |
| return effect->fEffectRef; |
| } |
| |
| |
| /** Helper used in subclass factory functions to unref the effect after it has been wrapped in a |
| GrEffectRef. E.g.: |
| |
| class EffectSubclass : public GrEffect { |
| public: |
| GrEffectRef* Create(ParamType1 param1, ParamType2 param2, ...) { |
| AutoEffectUnref effect(SkNEW_ARGS(EffectSubclass, (param1, param2, ...))); |
| return CreateEffectRef(effect); |
| } |
| */ |
| class AutoEffectUnref { |
| public: |
| AutoEffectUnref(GrEffect* effect) : fEffect(effect) { } |
| ~AutoEffectUnref() { fEffect->unref(); } |
| operator GrEffect*() { return fEffect; } |
| private: |
| GrEffect* fEffect; |
| }; |
| |
| /** Helper for getting the GrEffect out of a GrEffectRef and down-casting to a GrEffect subclass |
| */ |
| template <typename T> |
| static const T& CastEffect(const GrEffect& effectRef) { |
| return *static_cast<const T*>(&effectRef); |
| } |
| |
| /** |
| * If the effect subclass will read the destination pixel value then it must call this function |
| * from its constructor. Otherwise, when its generated backend-specific effect class attempts |
| * to generate code that reads the destination pixel it will fail. |
| */ |
| void setWillReadDstColor() { fWillReadDstColor = true; } |
| |
| /** |
| * If the effect will generate a backend-specific effect that will read the fragment position |
| * in the FS then it must call this method from its constructor. Otherwise, the request to |
| * access the fragment position will be denied. |
| */ |
| void setWillReadFragmentPosition() { fWillReadFragmentPosition = true; } |
| |
| private: |
| bool isEqual(const GrEffect& other) const { |
| if (&this->getFactory() != &other.getFactory()) { |
| return false; |
| } |
| bool result = this->onIsEqual(other); |
| #if GR_DEBUG |
| if (result) { |
| GrAssert(this->numTextures() == other.numTextures()); |
| for (int i = 0; i < this->numTextures(); ++i) { |
| GrAssert(*fTextureAccesses[i] == *other.fTextureAccesses[i]); |
| } |
| } |
| #endif |
| return result; |
| } |
| |
| /** Subclass implements this to support isEqual(). It will only be called if it is known that |
| the two effects are of the same subclass (i.e. they return the same object from |
| getFactory()).*/ |
| virtual bool onIsEqual(const GrEffect& other) const = 0; |
| |
| void EffectRefDestroyed() { fEffectRef = NULL; } |
| |
| friend class GrEffectRef; // to call EffectRefDestroyed() |
| friend class GrEffectStage; // to rewrap GrEffect in GrEffectRef when restoring an effect-stage |
| // from deferred state, to call isEqual on naked GrEffects, and |
| // to inc/dec deferred ref counts. |
| |
| SkSTArray<4, const GrTextureAccess*, true> fTextureAccesses; |
| SkSTArray<kMaxVertexAttribs, GrSLType, true> fVertexAttribTypes; |
| bool fWillReadDstColor; |
| bool fWillReadFragmentPosition; |
| GrEffectRef* fEffectRef; |
| |
| typedef GrRefCnt INHERITED; |
| }; |
| |
| inline GrEffectRef::GrEffectRef(GrEffect* effect) { |
| GrAssert(NULL != effect); |
| effect->ref(); |
| fEffect = effect; |
| } |
| |
| /** |
| * This creates an effect outside of the effect memory pool. The effect's destructor will be called |
| * at global destruction time. NAME will be the name of the created GrEffectRef. |
| */ |
| #define GR_CREATE_STATIC_EFFECT(NAME, EFFECT_CLASS, ARGS) \ |
| enum { \ |
| k_##NAME##_EffectRefOffset = GR_CT_ALIGN_UP(sizeof(EFFECT_CLASS), 8), \ |
| k_##NAME##_StorageSize = k_##NAME##_EffectRefOffset + sizeof(GrEffectRef) \ |
| }; \ |
| static SkAlignedSStorage<k_##NAME##_StorageSize> g_##NAME##_Storage; \ |
| static void* NAME##_RefLocation = (char*)g_##NAME##_Storage.get() + k_##NAME##_EffectRefOffset; \ |
| static GrEffect* NAME##_Effect SkNEW_PLACEMENT_ARGS(g_##NAME##_Storage.get(), EFFECT_CLASS, ARGS);\ |
| static SkAutoTDestroy<GrEffect> NAME##_ad(NAME##_Effect); \ |
| static GrEffectRef* NAME(GrEffect::CreateStaticEffectRef(NAME##_RefLocation, NAME##_Effect)); \ |
| static SkAutoTDestroy<GrEffectRef> NAME##_Ref_ad(NAME) |
| |
| |
| #endif |