Remove GP from drawstate, revision of invariant output for GP

src/gpu/GrGeometryProcessor.h

 /*
  * 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
 
@@ skipping 21 matching lines @@
     static const size_t kMaxSize = 32;
 
 private:
     uint8_t fData[kMaxSize];
 };
 
 class GrGLCaps;
 class GrGLGeometryProcessor;
 class GrOptDrawState;
 
+struct GrInitInvariantOutput;
+
+/*
+ * GrGeometryProcessors and GrPathProcessors may effect invariantColor
+ */
+class GrPrimitiveProcessor : public GrProcessor {
+public:
+    // TODO GPs and PPs have to provide an initial coverage because the coverage invariant code is
+    // broken right now
+    virtual uint8_t coverage() const = 0;
+    virtual void computeOutputColor(GrInitInvariantOutput* out) const = 0;

[bsalomon, 2014/12/10 15:27:00]

I'm wondering if this should be "getInvariantColorOutput"? computeOutputeColor
sounds like it is related to emitting code for color computation. (also not
crazy about the name we're using for FP... "compute" doesn't seem like a useful
verb. updateInvariant()? updateInvariantOutput?)

Also, I wonder if we should go ahead with a non-virtual foo, virtual onFoo
pattern here. It wouldn't surprise if we want to do stuff in the base class at
some point (e.g. overrides). If the foo() call is simply an inline call to onFoo
then there is no extra expense. The number of GPs is smallish now so making the
switch is less painful.

+    virtual void computeOutputCoverage(GrInitInvariantOutput* out) const = 0;
+
+private:
+    typedef GrProcessor INHERITED;
+};
+
 /**
  * A GrGeometryProcessor 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 {
+class GrGeometryProcessor : public GrPrimitiveProcessor {
 public:
     GrGeometryProcessor(GrColor color, uint8_t coverage = 0xff)
         : fVertexStride(0)
         , fColor(color)
         , fCoverage(coverage)
         , fWillUseGeoShader(false)
         , fHasVertexColor(false)
         , fHasVertexCoverage(false)
         , fHasLocalCoords(false) {}
 
@@ skipping 41 matching lines @@
         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->classID() != that.classID() || !this->hasSameTextureAccesses(that)) {
             return false;
         }
 
-        if (!fHasVertexColor && this->getColor() != that.getColor()) {
+        if (!fHasVertexColor && this->color() != that.color()) {
             return false;
         }
 
-        if (!fHasVertexCoverage && this->getCoverage() != that.getCoverage()) {
+        // TODO this is fragile, most gps set their coverage to 0xff so this is okay

[bsalomon, 2014/12/10 15:27:00]

what's the plan here?

+        if (!fHasVertexCoverage && this->coverage() != that.coverage()) {
             return false;
         }
         return this->onIsEqual(that);
     }
 
     struct InitBT {
         bool fOutputColor;
         bool fOutputCoverage;
         GrColor fColor;
         GrColor fCoverage;
     };
 
     virtual void initBatchTracker(GrBatchTracker*, const InitBT&) const {}
 
-    GrColor getColor() const { return fColor; }
-    uint8_t getCoverage() const { return fCoverage; }
+    GrColor color() const { return fColor; }
+    uint8_t coverage() const { return fCoverage; }
 
     // TODO this is a total hack until the gp can own whether or not it uses uniform
     // color / coverage
     bool hasVertexColor() const { return fHasVertexColor; }
     bool hasVertexCoverage() const { return fHasVertexCoverage; }
     bool hasLocalCoords() const { return fHasLocalCoords; }
 
-    void computeInvariantColor(GrInvariantOutput* inout) const;
+    virtual void computeOutputColor(GrInitInvariantOutput* out) const SK_OVERRIDE;
+    virtual void computeOutputCoverage(GrInitInvariantOutput* out) const SK_OVERRIDE;
 
 protected:
     /**
      * Subclasses call this from their constructor to register vertex attributes.  Attributes
      * will be padded to the nearest 4 bytes for performance reasons.
      * TODO After deferred geometry, we should do all of this inline in GenerateGeometry alongside
      * the struct used to actually populate the attributes
      */
     const GrAttribute& addVertexAttrib(const GrAttribute& attribute) {
         fVertexStride += attribute.fOffset;
         return fAttribs.push_back(attribute);
     }
 
     void setWillUseGeoShader() { fWillUseGeoShader = true; }
 
     // TODO hack see above
     void setHasVertexColor() { fHasVertexColor = true; }
     void setHasVertexCoverage() { fHasVertexCoverage = true; }
     void setHasLocalCoords() { fHasLocalCoords = true; }
 
+    virtual void onComputeOutputColor(GrInitInvariantOutput*) const {}
+    virtual void onComputeOutputCoverage(GrInitInvariantOutput*) const = 0;
+
 private:
     virtual bool onIsEqual(const GrGeometryProcessor&) const = 0;
 
     SkSTArray<kMaxVertexAttribs, GrAttribute, true> fAttribs;
     size_t fVertexStride;
     GrColor fColor;
+    // TODO HACK
+public:
     uint8_t fCoverage;
     bool fWillUseGeoShader;
     bool fHasVertexColor;
     bool fHasVertexCoverage;
     bool fHasLocalCoords;
 
     typedef GrProcessor INHERITED;
 };
+
+/*
+ * The path equivalent of the GP.  Can only upload uniform color.

[bsalomon, 2014/12/10 15:27:00]

Maybe a comment that we plan to extend responsibility to specify coord
transforms to the prim proc subclasses?

+ */
+class GrPathProcessor : public GrPrimitiveProcessor {
+public:
+    static GrPathProcessor* Create(GrColor color) {
+        return SkNEW_ARGS(GrPathProcessor, (color));
+    }
+
+    virtual const char* name() SK_OVERRIDE const { return "PathProcessor"; }
+    virtual uint8_t coverage() SK_OVERRIDE const { return 0xff; }

[bsalomon, 2014/12/10 15:27:00]

no need for virtual keyword on overrides.

+    virtual void computeOutputColor(GrInitInvariantOutput* out) const SK_OVERRIDE;
+    virtual void computeOutputCoverage(GrInitInvariantOutput* out) const SK_OVERRIDE;
+
+private:
+    GrPathProcessor(GrColor color) : fColor(color) {}
+    GrColor fColor;
+
+    typedef GrProcessor INHERITED;
+};
 #endif