Calculate stage stats in GrOptDrawState

src/gpu/GrOptDrawState.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrOptDrawState.h"
 
 #include "GrDrawState.h"
@@ skipping 23 matching lines @@
             sizeof(fFixedFunctionVertexAttribIndices));
 
 
     fInputColorIsUsed = true;
     fInputCoverageIsUsed = true;
 
     this->copyEffectiveColorStages(drawState);
     this->copyEffectiveCoverageStages(drawState);
     this->adjustFromBlendOpts();
     this->remapEffectStagesVAIndices();
+    this->getStageStats();
 };
 
 void GrOptDrawState::initializeVAIndexMap() {
     fVAIndexMap.reset(fVACount);
     int* map = fVAIndexMap.get();
     for (int i = 0; i < fVACount; ++i) {
         map[i] = i;
     }
 }
 
@@ skipping 152 matching lines @@
         }
     }
     if (ds.numCoverageStages() > 0) {
         fCoverageStages.reset(&ds.getCoverageStage(firstCoverageStage),
                               ds.numCoverageStages() - firstCoverageStage);
     } else {
         fCoverageStages.reset();
     }
 }
 
+static void get_stage_stats(const GrEffectStage& stage, bool* readsDst,
+                            bool* readsFragPosition, bool* requiresVertexShader) {
+    if (stage.getEffect()->willReadDstColor()) {
+        *readsDst = true;
+    }
+    if (stage.getEffect()->willReadFragmentPosition()) {
+        *readsFragPosition = true;
+    }
+    if (stage.getEffect()->requiresVertexShader()) {

[bsalomon, 2014/09/05 15:27:54]

this is going away... reqVS will be equivalent to this->hasGeometryProcessor().

+        *requiresVertexShader = true;
+    }
+}
+
+void GrOptDrawState::getStageStats() {
+    fReadsDst = false;
+    fReadsFragPosition = false;
+    fRequiresVertexShader = false;
+
+    for (int s = 0; s < this->numColorStages(); ++s) {
+        const GrEffectStage& stage = this->getColorStage(s);
+        get_stage_stats(stage, &fReadsDst, &fReadsFragPosition, &fRequiresVertexShader);
+    }
+    for (int s = 0; s < this->numCoverageStages(); ++s) {
+        const GrEffectStage& stage = this->getCoverageStage(s);
+        get_stage_stats(stage, &fReadsDst, &fReadsFragPosition, &fRequiresVertexShader);
+    }
+}
+
 bool GrOptDrawState::operator== (const GrOptDrawState& that) const {
     return this->isEqual(that);
 }