Add XferProcessor factory in GrPaint and GrDrawState.

src/gpu/GrDrawState.h

Index: src/gpu/GrDrawState.h
diff --git a/src/gpu/GrDrawState.h b/src/gpu/GrDrawState.h
index a049f1d8071e725d9dc96a3a1ac5b09a1c9dadbf..e699f85236da2efc4e63b648ef8ed9078d612bca 100644
--- a/src/gpu/GrDrawState.h
+++ b/src/gpu/GrDrawState.h
@@ -215,6 +215,11 @@ public:
         }
     }
 
+    /**
+     * Determines whether the output of the coverage stages will be single component.
+     */
+    bool coverageWillBeSingleComponent() const;

[bsalomon, 2014/11/26 21:02:45]

needs to be public?

[egdaniel, 2014/12/01 18:18:24]

It is a query used by PD-XPF for checking RGBCoverage. Currently we hide DS's
invariant output from all classes except GrOptDrawState. I don't want to open
the flood gate to friending all effects.

I guess the change we can make is to have this function (and in future cl's
createXferProcessor(...)) take in the invariant color and coverage instead of
the draw state. But this does mess with the query's in the text context for
applyRGBCoverage since they won't have access to the DS invariants to pass in.

I kind of feel in the end public queries on the DS end up being clearer and
cleaner.

[bsalomon, 2014/12/01 19:24:39]

I don't think PD-XPF should be allowed to see GrDrawState at all. It's private.
I think we need some encapsulation of just the info that XP(F) is allowed to
see.

+
     /// @}
 
     /**
@@ -260,6 +265,10 @@ public:
 
     bool hasGeometryProcessor() const { return SkToBool(fGeometryProcessor.get()); }
     const GrGeometryProcessor* getGeometryProcessor() const { return fGeometryProcessor.get(); }
+
+    bool hasXPFactory() const { return SkToBool(fXPFactory.get()); }
+    const GrXPFactory* getXPFactory() const { return fXPFactory.get(); }
+
     const GrFragmentStage& getColorStage(int idx) const { return fColorStages[idx]; }
     const GrFragmentStage& getCoverageStage(int idx) const { return fCoverageStages[idx]; }
 
@@ -783,6 +792,7 @@ private:
     GrBlendCoeff                            fSrcBlend;
     GrBlendCoeff                            fDstBlend;
     SkAutoTUnref<const GrGeometryProcessor> fGeometryProcessor;
+    SkAutoTUnref<const GrXPFactory>         fXPFactory;
     FragmentStageArray                      fColorStages;
     FragmentStageArray                      fCoverageStages;
     uint32_t                                fHints;