Revise attribute binding interface

src/gpu/gl/GrGLProgramDesc.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLProgramDesc.h"
 #include "GrBackendEffectFactory.h"
 #include "GrDrawEffect.h"
@@ skipping 14 matching lines @@
     bool skipCoverage = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
 
     bool skipColor = SkToBool(blendOpts & (GrDrawState::kEmitTransBlack_BlendOptFlag |
                                            GrDrawState::kEmitCoverage_BlendOptFlag));
 
     // The descriptor is used as a cache key. Thus when a field of the
     // descriptor will not affect program generation (because of the attribute
     // bindings in use or other descriptor field settings) it should be set
     // to a canonical value to avoid duplicate programs with different keys.
 
-    // Must initialize all fields or cache will have false negatives!
-    desc->fAttribBindings = drawState.getAttribBindings();
 
     desc->fEmitsPointSize = isPoints;
 
-    bool requiresAttributeColors =
-        !skipColor && SkToBool(desc->fAttribBindings & GrDrawState::kColor_AttribBindingsBit);
-    bool requiresAttributeCoverage =
-        !skipCoverage && SkToBool(desc->fAttribBindings & GrDrawState::kCoverage_AttribBindingsBit);
+    bool requiresColorAttrib = !skipColor && drawState.hasColorVertexAttribute();
+    bool requiresCoverageAttrib = !skipCoverage && drawState.hasCoverageVertexAttribute();
+    // we only need the local coords if we're actually going to generate effect code
+    bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
+                                    drawState.hasLocalCoordAttribute();
 
     // fColorInput/fCoverageInput records how colors are specified for the program so we strip the
     // bits from the bindings to avoid false negatives when searching for an existing program in the
     // cache.
-    desc->fAttribBindings &=
-        ~(GrDrawState::kColor_AttribBindingsBit | GrDrawState::kCoverage_AttribBindingsBit);
 
     desc->fColorFilterXfermode = skipColor ? SkXfermode::kDst_Mode : drawState.getColorFilterMode();
 
-    // no reason to do edge aa or look at per-vertex coverage if coverage is ignored
-    if (skipCoverage) {
-        desc->fAttribBindings &= ~(GrDrawState::kCoverage_AttribBindingsBit);
-    }
 
     bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
     bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
-                             (!requiresAttributeColors && 0xffffffff == drawState.getColor());
+                             (!requiresColorAttrib && 0xffffffff == drawState.getColor());
     if (colorIsTransBlack) {
         desc->fColorInput = kTransBlack_ColorInput;
     } else if (colorIsSolidWhite) {
         desc->fColorInput = kSolidWhite_ColorInput;
-    } else if (GR_GL_NO_CONSTANT_ATTRIBUTES && !requiresAttributeColors) {
+    } else if (GR_GL_NO_CONSTANT_ATTRIBUTES && !requiresColorAttrib) {
         desc->fColorInput = kUniform_ColorInput;
     } else {
         desc->fColorInput = kAttribute_ColorInput;
     }
 
-    bool covIsSolidWhite = !requiresAttributeCoverage && 0xffffffff == drawState.getCoverage();
+    bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverage();
 
     if (skipCoverage) {
         desc->fCoverageInput = kTransBlack_ColorInput;
     } else if (covIsSolidWhite) {
         desc->fCoverageInput = kSolidWhite_ColorInput;
-    } else if (GR_GL_NO_CONSTANT_ATTRIBUTES && !requiresAttributeCoverage) {
+    } else if (GR_GL_NO_CONSTANT_ATTRIBUTES && !requiresCoverageAttrib) {
         desc->fCoverageInput = kUniform_ColorInput;
     } else {
         desc->fCoverageInput = kAttribute_ColorInput;
     }
 
     int lastEnabledStage = -1;
 
     for (int s = 0; s < GrDrawState::kNumStages; ++s) {
 
         bool skip = s < drawState.getFirstCoverageStage() ? skipColor : skipCoverage;
         if (!skip && drawState.isStageEnabled(s)) {
             lastEnabledStage = s;
             const GrEffectRef& effect = *drawState.getStage(s).getEffect();
             const GrBackendEffectFactory& factory = effect->getFactory();
-            bool explicitLocalCoords = (drawState.getAttribBindings() &
-                                        GrDrawState::kLocalCoords_AttribBindingsBit);
-            GrDrawEffect drawEffect(drawState.getStage(s), explicitLocalCoords);
+            GrDrawEffect drawEffect(drawState.getStage(s), requiresLocalCoordAttrib);
             desc->fEffectKeys[s] = factory.glEffectKey(drawEffect, gpu->glCaps());
         } else {
             desc->fEffectKeys[s] = 0;
         }
     }
 
     desc->fDualSrcOutput = kNone_DualSrcOutput;
 
     // Currently the experimental GS will only work with triangle prims (and it doesn't do anything
     // other than pass through values from the VS to the FS anyway).
@@ skipping 13 matching lines @@
     int firstCoverageStage = GrDrawState::kNumStages;
     desc->fDiscardIfZeroCoverage = false; // Enabled below if stenciling and there is coverage.
     bool hasCoverage = false;
     // If we're rendering coverage-as-color then it's as though there are no coverage stages.
     if (!drawState.isCoverageDrawing()) {
         // We can have coverage either through a stage or coverage vertex attributes.
         if (drawState.getFirstCoverageStage() <= lastEnabledStage) {
             firstCoverageStage = drawState.getFirstCoverageStage();
             hasCoverage = true;
         } else {
-            hasCoverage = requiresAttributeCoverage;
+            hasCoverage = requiresCoverageAttrib;
         }
     }
 
     if (hasCoverage) {
         // color filter is applied between color/coverage computation
         if (SkXfermode::kDst_Mode != desc->fColorFilterXfermode) {
             desc->fFirstCoverageStage = firstCoverageStage;
         }
 
         // If we're stenciling then we want to discard samples that have zero coverage
@@ skipping 14 matching lines @@
                 desc->fDualSrcOutput = kCoverageISA_DualSrcOutput;
                 desc->fFirstCoverageStage = firstCoverageStage;
             } else if (kSC_GrBlendCoeff == dstCoeff) {
                 // SA dst coeff becomes 1-(1-SA)*coverage when dst is partially covered.
                 desc->fDualSrcOutput = kCoverageISC_DualSrcOutput;
                 desc->fFirstCoverageStage = firstCoverageStage;
             }
         }
     }
 
-    desc->fPositionAttributeIndex = drawState.getAttribIndex(GrDrawState::kPosition_AttribIndex);
-    if (requiresAttributeColors) {
-        desc->fColorAttributeIndex = drawState.getAttribIndex(GrDrawState::kColor_AttribIndex);
+    desc->fPositionAttributeIndex = drawState.positionAttributeIndex();
+    desc->fLocalCoordAttributeIndex = drawState.localCoordAttributeIndex();
+
+    // For constant color and coverage we need an attribute with an index beyond those already set
+    int availableAttributeIndex = drawState.getVertexAttribCount();
+    if (requiresColorAttrib) {
+        desc->fColorAttributeIndex = drawState.colorVertexAttributeIndex();
+    } else if (GrGLProgramDesc::kAttribute_ColorInput == desc->fColorInput) {
+        GrAssert(availableAttributeIndex < GrDrawState::kMaxVertexAttribCnt);
+        desc->fColorAttributeIndex = availableAttributeIndex;
+        availableAttributeIndex++;
     } else {
-        desc->fColorAttributeIndex = GrDrawState::kColorOverrideAttribIndexValue;
-    }
-    if (requiresAttributeCoverage) {
-        desc->fCoverageAttributeIndex = drawState.getAttribIndex(GrDrawState::kCoverage_AttribIndex);
-    } else {
-        desc->fCoverageAttributeIndex = GrDrawState::kCoverageOverrideAttribIndexValue;
-    }
-    if (desc->fAttribBindings & GrDrawState::kLocalCoords_AttribBindingsBit) {
-        desc->fLocalCoordsAttributeIndex = drawState.getAttribIndex(GrDrawState::kLocalCoords_AttribIndex);
+        desc->fColorAttributeIndex = -1;
     }
 
-#if GR_DEBUG
-    // Verify valid vertex attribute state. These assertions should probably be done somewhere
-    // higher up the callstack
-    const GrVertexAttrib* vertexAttribs = drawState.getVertexAttribs();
-    GrAssert(desc->fPositionAttributeIndex < GrDrawState::kVertexAttribCnt);
-    GrAssert(GrGLAttribTypeToLayout(vertexAttribs[desc->fPositionAttributeIndex].fType).fCount == 2);
-    if (requiresAttributeColors) {
-        GrAssert(desc->fColorAttributeIndex < GrDrawState::kVertexAttribCnt);
-        GrAssert(GrGLAttribTypeToLayout(vertexAttribs[desc->fColorAttributeIndex].fType).fCount == 4);
+    if (requiresCoverageAttrib) {
+        desc->fCoverageAttributeIndex = drawState.coverageVertexAttributeIndex();
+    } else if (GrGLProgramDesc::kAttribute_ColorInput == desc->fCoverageInput) {
+        GrAssert(availableAttributeIndex < GrDrawState::kMaxVertexAttribCnt);
+        desc->fCoverageAttributeIndex = availableAttributeIndex;
+    } else {
+        desc->fCoverageAttributeIndex = -1;
     }
-    if (requiresAttributeCoverage) {
-        GrAssert(desc->fCoverageAttributeIndex < GrDrawState::kVertexAttribCnt);
-        GrAssert(GrGLAttribTypeToLayout(vertexAttribs[desc->fCoverageAttributeIndex].fType).fCount == 4);
-    }
-    if (desc->fAttribBindings & GrDrawState::kLocalCoords_AttribBindingsBit) {
-        GrAssert(desc->fLocalCoordsAttributeIndex < GrDrawState::kVertexAttribCnt);
-        GrAssert(GrGLAttribTypeToLayout(vertexAttribs[desc->fLocalCoordsAttributeIndex].fType).fCount == 2);
-    }
-#endif
 }