Move GrInvariantOutput out of GrProcessor and into its own class.

include/gpu/GrProcessor.h

 /*
  * 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 GrProcessor_DEFINED
 #define GrProcessor_DEFINED
 
 #include "GrBackendProcessorFactory.h"
 #include "GrColor.h"
 #include "GrProcessorUnitTest.h"
 #include "GrProgramElement.h"
 #include "GrTextureAccess.h"
 #include "SkMath.h"
 
 class GrContext;
 class GrCoordTransform;
+class GrInvariantOutput;
 
 /** Provides custom shader code to the Ganesh shading pipeline. GrProcessor objects *must* be
     immutable: after being constructed, their fields may not change.
 
     Dynamically allocated GrProcessors are managed by a per-thread memory pool. The ref count of an
     processor must reach 0 before the thread terminates and the pool is destroyed. To create a
     static processor use the helper macro GR_CREATE_STATIC_PROCESSOR declared below.
  */
 class GrProcessor : public GrProgramElement {
 public:
     SK_DECLARE_INST_COUNT(GrProcessor)
 
     virtual ~GrProcessor();
 
-    struct InvariantOutput{
-        InvariantOutput() : fColor(0), fValidFlags(0), fIsSingleComponent(false),
-                            fNonMulStageFound(false), fWillUseInputColor(true) {}
-
-        enum ReadInput {
-            kWill_ReadInput,
-            kWillNot_ReadInput,
-        };
-
-        void mulByUnknownOpaqueColor() {
-            if (this->isOpaque()) {
-                fValidFlags = kA_GrColorComponentFlag;
-                fIsSingleComponent = false;
-            } else {
-                // Since the current state is not opaque we no longer care if the color being
-                // multiplied is opaque.
-                this->mulByUnknownColor(); 
-            }
-        }
-
-        void mulByUnknownColor() {
-            if (this->hasZeroAlpha()) {
-                this->internalSetToTransparentBlack();
-            } else {
-                this->internalSetToUnknown();
-            }
-        }
-
-        void mulByUnknownAlpha() {
-            if (this->hasZeroAlpha()) {
-                this->internalSetToTransparentBlack();
-            } else {
-                // We don't need to change fIsSingleComponent in this case
-                fValidFlags = 0;
-            }
-        }
-
-        void mulByKnownAlpha(uint8_t alpha) {
-            if (this->hasZeroAlpha() || 0 == alpha) {
-                this->internalSetToTransparentBlack();
-            } else {
-                if (alpha != 255) {
-                    // Multiply color by alpha
-                    fColor = GrColorPackRGBA(SkMulDiv255Round(GrColorUnpackR(fColor), alpha),
-                                             SkMulDiv255Round(GrColorUnpackG(fColor), alpha),
-                                             SkMulDiv255Round(GrColorUnpackB(fColor), alpha),
-                                             SkMulDiv255Round(GrColorUnpackA(fColor), alpha));
-                }
-            }
-        }
-
-        void invalidateComponents(uint8_t invalidateFlags, ReadInput readsInput) {
-            fValidFlags &= ~invalidateFlags;
-            fIsSingleComponent = false;
-            if (kWillNot_ReadInput == readsInput) {
-                fWillUseInputColor = false;
-            }
-        }
-
-        void setToOther(uint8_t validFlags, GrColor color, ReadInput readsInput) {
-            fValidFlags = validFlags;
-            fColor = color;
-            fIsSingleComponent = false;
-            fNonMulStageFound = true;
-            if (kWillNot_ReadInput == readsInput) {
-                fWillUseInputColor = false;
-            }
-        }
-
-        void setToUnknown(ReadInput readsInput) {
-            this->internalSetToUnknown();
-            fNonMulStageFound= true;
-            if (kWillNot_ReadInput == readsInput) {
-                fWillUseInputColor = false;
-            }
-        }
-
-        bool isOpaque() const {
-            return ((fValidFlags & kA_GrColorComponentFlag) && 0xFF == GrColorUnpackA(fColor));
-        }
-
-        bool isSolidWhite() const {
-            return (fValidFlags == kRGBA_GrColorComponentFlags && 0xFFFFFFFF == fColor);
-        }
-
-        GrColor color() const { return fColor; }
-        uint8_t validFlags() const { return fValidFlags; }
-
-        /**
-         * If isSingleComponent is true, then the flag values for r, g, b, and a must all be the
-         * same. If the flags are all set then all color components must be equal.
-         */
-        SkDEBUGCODE(void validate() const;)
-
-    private:
-        void internalSetToTransparentBlack() {
-            fValidFlags = kRGBA_GrColorComponentFlags;
-            fColor = 0;
-            fIsSingleComponent = true;
-        }
-
-        void internalSetToUnknown() {
-            fValidFlags = 0;
-            fIsSingleComponent = false;
-        }
-
-        bool hasZeroAlpha() const {
-            return ((fValidFlags & kA_GrColorComponentFlag) && 0 == GrColorUnpackA(fColor));
-        }
-
-        SkDEBUGCODE(bool colorComponentsAllEqual() const;)
-        /**
-         * If alpha is valid, check that any valid R,G,B values are <= A
-         */
-        SkDEBUGCODE(bool validPreMulColor() const;)
-
-        // Friended class that have "controller" code which loop over stages calling
-        // computeInvarianteOutput(). These controllers may need to manually adjust the internal
-        // members of InvariantOutput
-        friend class GrDrawState;
-        friend class GrOptDrawState;
-        friend class GrPaint;
-        friend class GrProcessor;
-
-        GrColor fColor;
-        uint32_t fValidFlags;
-        bool fIsSingleComponent;
-        bool fNonMulStageFound;
-        bool fWillUseInputColor;
-    };
-
     /**
      * This function is used to perform optimizations. When called the invarientOuput param
      * indicate whether the input components to this processor in the FS will have known values.
      * In inout the validFlags member is a bitfield of GrColorComponentFlags. The isSingleComponent
      * member indicates whether the input will be 1 or 4 bytes. The function updates the members of
      * inout to indicate known values of its output. A component of the color member only has
      * meaning if the corresponding bit in validFlags is set.
      */
-    void computeInvariantOutput(InvariantOutput* inout) const {
-        inout->fWillUseInputColor = true;
-        this->onComputeInvariantOutput(inout);
-#ifdef SK_DEBUG
-        inout->validate();
-#endif
-    }
+    void computeInvariantOutput(GrInvariantOutput* inout) const; 
 
     /** 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,
         GrTBackendProcessorFactory. It is templated on the subclass of GrProcessor. The subclass
         must have a nested type (or typedef) named GLProcessor which will be the subclass of
         GrGLProcessor created by the factory.
 
         Example:
         class MyCustomProcessor : public GrProcessor {
         ...
@@ skipping 50 matching lines @@
     bool hasSameTextureAccesses(const GrProcessor&) const;
 
     /**
      * If the prcoessor will generate a backend-specific processor 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:
-
     /** 
      * Subclass implements this to support getConstantColorComponents(...).
      */
-    virtual void onComputeInvariantOutput(InvariantOutput* inout) const = 0;
+    virtual void onComputeInvariantOutput(GrInvariantOutput* inout) const = 0;
 
     SkSTArray<4, const GrTextureAccess*, true>   fTextureAccesses;
     bool                                         fWillReadFragmentPosition;
 
     typedef GrProgramElement INHERITED;
 };
 
 
 /**
  * This creates a processor outside of the memory pool. The processor's destructor will be called
  * at global destruction time. NAME will be the name of the created instance.
  */
 #define GR_CREATE_STATIC_PROCESSOR(NAME, PROC_CLASS, ARGS)                                 \
 static SkAlignedSStorage<sizeof(PROC_CLASS)> g_##NAME##_Storage;                           \
 static PROC_CLASS* NAME SkNEW_PLACEMENT_ARGS(g_##NAME##_Storage.get(), PROC_CLASS, ARGS);  \
 static SkAutoTDestroy<GrProcessor> NAME##_ad(NAME);
 
 #endif