Adds local coords to GrEffect system.

src/gpu/GrDrawState.h

Index: src/gpu/GrDrawState.h
===================================================================
--- src/gpu/GrDrawState.h	(revision 8216)
+++ src/gpu/GrDrawState.h	(working copy)
@@ -257,38 +257,26 @@
     /**
      * The vertex data used by the current program is represented as a bitfield
      * of flags. Programs always use positions and may also use texture
-     * coordinates, per-vertex colors, per-vertex coverage and edge data. Each
-     * stage can use the explicit texture coordinates as its input texture
-     * coordinates or it may use the positions as texture coordinates.
+     * coordinates, per-vertex colors, per-vertex coverage and edge data. The
+     * local coords accessible by effects may either come from positions or
+     * be specified explicitly.
      */
 
     /**
-     * Generates a bit indicating that a texture stage uses texture coordinates
-     *
-     * @param stageIdx    the stage that will use texture coordinates.
-     *
-     * @return the bit to add to a GrAttribBindings bitfield.
-     */
-    static int ExplicitTexCoordAttribBindingsBit(int stageIdx) {
-        GrAssert(stageIdx < kNumStages);
-        return (1 << stageIdx);
-    }
-
-    static bool StageBindsExplicitTexCoords(GrAttribBindings bindings, int stageIdx);
-
-    /**
      * Additional Bits that can be specified in GrAttribBindings.
      */
     enum AttribBindingsBits {
+        /** explicit local coords are provided (instead of using pre-view-matrix positions) */

[jvanverth1, 2013/03/19 15:11:59]

It may not matter, but for consistency's sake it'd be good to have the bit order
here match the index order below. Then the bit for an index is 1 << (index-1),
ignoring position. Or maybe set kPosition_AttribBindingsBit to 0x1, shift
everything else up one bit, and have kDefault_AttribBindings set to
kPosition_AttribBindings bit. That would get rid of the (i ==
kPosition_AttribIndex) check in operator==(), below.

[bsalomon, 2013/03/19 15:22:25]

Can do... but if we're about to get rid of them is it worth it?

[jvanverth1, 2013/03/19 15:36:51]

Well, like I said, it may not matter... :)

+        kLocalCoords_AttribBindingsBit        = 0x1,
         /* program uses colors (GrColor) */
-        kColor_AttribBindingsBit              = 1 << (kNumStages + 0),
+        kColor_AttribBindingsBit              = 0x2,
         /* program uses coverage (GrColor)
          */
-        kCoverage_AttribBindingsBit           = 1 << (kNumStages + 1),
+        kCoverage_AttribBindingsBit           = 0x4,
         /* program uses edge data. Distance to the edge is used to
          * compute a coverage. See GrDrawState::setVertexEdgeType().
          */
-        kEdge_AttribBindingsBit               = 1 << (kNumStages + 2),
+        kEdge_AttribBindingsBit               = 0x8,
         // for below assert
         kDummyAttribBindingsBit,
         kHighAttribBindingsBit = kDummyAttribBindingsBit - 1
@@ -313,17 +301,6 @@
     // Helpers for picking apart attribute bindings
 
     /**
-     * Helper function to determine if program uses explicit texture
-     * coordinates.
-     *
-     * @param  bindings  attribute bindings to query
-     *
-     * @return true if program uses texture coordinates,
-     *         false otherwise.
-     */
-    static bool AttributesBindExplicitTexCoords(GrAttribBindings bindings);
-
-    /**
      * Determines whether src alpha is guaranteed to be one for all src pixels
      */
     bool srcAlphaWillBeOne(GrAttribBindings) const;
@@ -356,9 +333,9 @@
         kColor_AttribIndex,
         kCoverage_AttribIndex,
         kEdge_AttribIndex,
-        kTexCoord_AttribIndex,
+        kLocalCoords_AttribIndex,
 
-        kLast_AttribIndex = kTexCoord_AttribIndex
+        kLast_AttribIndex = kLocalCoords_AttribIndex
     };
     static const int kAttribIndexCount = kLast_AttribIndex + 1;
 
@@ -410,7 +387,7 @@
 
     /**
      * Add a color filter that can be represented by a color and a mode. Applied
-     * after color-computing texture stages.
+     * after color-computing effect stages.
      */
     void setColorFilter(GrColor c, SkXfermode::Mode mode) {
         fCommon.fColorFilterColor = c;
@@ -492,7 +469,7 @@
     }
 
     /**
-     * Creates a GrSimpleTextureEffect.
+     * Creates a GrSimpleTextureEffect that uses local coords as texture coordinates.
      */
     void createTextureEffect(int stageIdx, GrTexture* texture, const SkMatrix& matrix) {
         GrAssert(!this->getStage(stageIdx).getEffect());
@@ -551,42 +528,16 @@
     }
 
     /**
-     * Called when the source coord system is changing. preConcat gives the transformation from the
-     * old coord system to the new coord system.
+     * Called when the source coord system is changing. This ensures that effects will see the
+     * correct local coordinates. oldToNew gives the transformation from the old coord system in
+     * which the geometry was specified to the new coordinate system from which it will be rendered.
      */
-    void preConcatStageMatrices(const SkMatrix& preConcat) {
-        this->preConcatStageMatrices(~0U, preConcat);
-    }
-    /**
-     * Version of above that applies the update matrix selectively to stages via a mask.
-     */
-    void preConcatStageMatrices(uint32_t stageMask, const SkMatrix& preConcat) {
+    void localCoordChange(const SkMatrix& oldToNew) {
         for (int i = 0; i < kNumStages; ++i) {
-            if (((1 << i) & stageMask) && this->isStageEnabled(i)) {
-                fStages[i].preConcatCoordChange(preConcat);
-            }
-        }
-    }
-
-    /**
-     * Called when the source coord system is changing. preConcatInverse is the inverse of the
-     * transformation from the old coord system to the new coord system. Returns false if the matrix
-     * cannot be inverted.
-     */
-    bool preConcatStageMatricesWithInverse(const SkMatrix& preConcatInverse) {
-        SkMatrix inv;
-        bool computed = false;
-        for (int i = 0; i < kNumStages; ++i) {
             if (this->isStageEnabled(i)) {
-                if (!computed && !preConcatInverse.invert(&inv)) {
-                    return false;
-                } else {
-                    computed = true;
-                }
-                fStages[i].preConcatCoordChange(preConcatInverse);
+                fStages[i].localCoordChange(oldToNew);
             }
         }
-        return true;
     }
 
     /// @}
@@ -827,11 +778,9 @@
     public:
         AutoViewMatrixRestore() : fDrawState(NULL) {}
 
-        AutoViewMatrixRestore(GrDrawState* ds,
-                              const SkMatrix& preconcatMatrix,
-                              uint32_t explicitCoordStageMask = 0) {
+        AutoViewMatrixRestore(GrDrawState* ds, const SkMatrix& preconcatMatrix) {
             fDrawState = NULL;
-            this->set(ds, preconcatMatrix, explicitCoordStageMask);
+            this->set(ds, preconcatMatrix);
         }
 
         ~AutoViewMatrixRestore() { this->restore(); }
@@ -841,9 +790,7 @@
          */
         void restore();
 
-        void set(GrDrawState* drawState,
-                 const SkMatrix& preconcatMatrix,
-                 uint32_t explicitCoordStageMask = 0);
+        void set(GrDrawState* drawState, const SkMatrix& preconcatMatrix);
 
         bool isSet() const { return NULL != fDrawState; }
 
@@ -870,15 +817,14 @@
          * positions, then we don't want to modify its matrix. The explicitCoordStageMask is used
          * to specify such stages.
          */
-        AutoDeviceCoordDraw(GrDrawState* drawState,
-                            uint32_t explicitCoordStageMask = 0) {
+        AutoDeviceCoordDraw(GrDrawState* drawState) {
             fDrawState = NULL;
-            this->set(drawState, explicitCoordStageMask);
+            this->set(drawState);
         }
 
         ~AutoDeviceCoordDraw() { this->restore(); }
 
-        bool set(GrDrawState* drawState, uint32_t explicitCoordStageMask = 0);
+        bool set(GrDrawState* drawState);
 
         /**
          * Returns true if this object was successfully initialized on to a GrDrawState. It may
@@ -1195,8 +1141,7 @@
             return false;
         }
         for (int i = 0; i < kAttribIndexCount; ++i) {
-            if ((i == kPosition_AttribIndex ||
-                    s.fCommon.fAttribBindings & kAttribIndexMasks[i]) &&

[jvanverth1, 2013/03/19 15:11:59]

Can we get rid of kAttribIndexMasks now? It was only created because the
texCoords took up multiple bits.

[bsalomon, 2013/03/19 15:22:25]

Yes, I was planning to do that in a follow-up change.

+            if ((i == kPosition_AttribIndex || s.fCommon.fAttribBindings & (1 << i)) &&
                 fAttribIndices[i] != s.fAttribIndices[i]) {
                 return false;
             }