| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrGeometryProcessor_DEFINED |
| #define GrGeometryProcessor_DEFINED |
| |
| #include "GrGeometryData.h" |
| #include "GrProcessor.h" |
| #include "GrShaderVar.h" |
| |
| /** |
| * A GrGeomteryProcessor is used to perform computation in the vertex shader and |
| * add support for custom vertex attributes. A GrGemeotryProcessor is typically |
| * tied to the code that does a specific type of high-level primitive rendering |
| * (e.g. anti-aliased circle rendering). The GrGeometryProcessor used for a draw is |
| * specified using GrDrawState. There can only be one geometry processor active for |
| * a draw. The custom vertex attributes required by the geometry processor must be |
| * added to the vertex attribute array specified on the GrDrawState. |
| * GrGeometryProcessor subclasses should be immutable after construction. |
| */ |
| class GrGeometryProcessor : public GrProcessor { |
| public: |
| GrGeometryProcessor() |
| : fWillUseGeoShader(false) {} |
| |
| virtual const GrBackendGeometryProcessorFactory& getFactory() const = 0; |
| |
| /* |
| * This only has a max because GLProgramsTest needs to generate test arrays, and these have to |
| * be static |
| * TODO make this truly dynamic |
| */ |
| static const int kMaxVertexAttribs = 2; |
| typedef SkTArray<GrShaderVar, true> VertexAttribArray; |
| |
| const VertexAttribArray& getVertexAttribs() const { return fVertexAttribs; } |
| |
| bool willUseGeoShader() const { return fWillUseGeoShader; } |
| |
| /** Returns true if this and other processor conservatively draw identically. It can only return |
| true when the two prcoessors 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 processors |
| would generate the same shader code. To test for identical code generation use the |
| processors' keys computed by the GrBackendEffectFactory. */ |
| bool isEqual(const GrGeometryProcessor& that) const { |
| if (&this->getFactory() != &that.getFactory() || !this->hasSameTextureAccesses(that)) { |
| return false; |
| } |
| return this->onIsEqual(that); |
| } |
| |
| protected: |
| /** |
| * Subclasses call this from their constructor to register vertex attributes (at most |
| * kMaxVertexAttribs). This must only be called from the constructor because GrProcessors are |
| * immutable. |
| */ |
| const GrShaderVar& addVertexAttrib(const GrShaderVar& var) { |
| SkASSERT(fVertexAttribs.count() < kMaxVertexAttribs); |
| return fVertexAttribs.push_back(var); |
| } |
| |
| void setWillUseGeoShader() { fWillUseGeoShader = true; } |
| |
| private: |
| virtual bool onIsEqual(const GrGeometryProcessor&) const = 0; |
| |
| SkSTArray<kMaxVertexAttribs, GrShaderVar, true> fVertexAttribs; |
| bool fWillUseGeoShader; |
| |
| typedef GrProcessor INHERITED; |
| }; |
| |
| #endif |