74077b9941
TBR= BUG=skia: Committed: https://skia.googlesource.com/skia/+/852ae80b9c3c6fd53f993ac35133d80863993cbe Review URL: https://codereview.chromium.org/671023002
79 lines
2.9 KiB
C++
79 lines
2.9 KiB
C++
/*
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* Copyright 2013 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef GrGeometryProcessor_DEFINED
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#define GrGeometryProcessor_DEFINED
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#include "GrProcessor.h"
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#include "GrShaderVar.h"
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/**
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* A GrGeomteryProcessor is used to perform computation in the vertex shader and
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* add support for custom vertex attributes. A GrGemeotryProcessor is typically
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* tied to the code that does a specific type of high-level primitive rendering
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* (e.g. anti-aliased circle rendering). The GrGeometryProcessor used for a draw is
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* specified using GrDrawState. There can only be one geometry processor active for
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* a draw. The custom vertex attributes required by the geometry processor must be
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* added to the vertex attribute array specified on the GrDrawState.
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* GrGeometryProcessor subclasses should be immutable after construction.
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*/
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class GrGeometryProcessor : public GrProcessor {
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public:
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GrGeometryProcessor()
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: fWillUseGeoShader(false) {}
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virtual const GrBackendGeometryProcessorFactory& getFactory() const = 0;
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/*
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* This only has a max because GLProgramsTest needs to generate test arrays, and these have to
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* be static
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* TODO make this truly dynamic
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*/
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static const int kMaxVertexAttribs = 2;
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typedef SkTArray<GrShaderVar, true> VertexAttribArray;
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const VertexAttribArray& getVertexAttribs() const { return fVertexAttribs; }
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bool willUseGeoShader() const { return fWillUseGeoShader; }
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/** Returns true if this and other processor conservatively draw identically. It can only return
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true when the two prcoessors are of the same subclass (i.e. they return the same object from
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from getFactory()).
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A return value of true from isEqual() should not be used to test whether the prcoessors
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would generate the same shader code. To test for identical code generation use the
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processors' keys computed by the GrBackendEffectFactory. */
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bool isEqual(const GrGeometryProcessor& that) const {
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if (&this->getFactory() != &that.getFactory() || !this->hasSameTextureAccesses(that)) {
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return false;
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}
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return this->onIsEqual(that);
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}
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protected:
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/**
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* Subclasses call this from their constructor to register vertex attributes (at most
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* kMaxVertexAttribs). This must only be called from the constructor because GrProcessors are
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* immutable.
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*/
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const GrShaderVar& addVertexAttrib(const GrShaderVar& var) {
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SkASSERT(fVertexAttribs.count() < kMaxVertexAttribs);
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return fVertexAttribs.push_back(var);
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}
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void setWillUseGeoShader() { fWillUseGeoShader = true; }
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private:
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virtual bool onIsEqual(const GrGeometryProcessor&) const = 0;
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SkSTArray<kMaxVertexAttribs, GrShaderVar, true> fVertexAttribs;
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bool fWillUseGeoShader;
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typedef GrProcessor INHERITED;
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};
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#endif
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