Add GrEllipseEdgeEffect

src/gpu/gl/GrGLProgram.cpp

Index: src/gpu/gl/GrGLProgram.cpp
===================================================================
--- src/gpu/gl/GrGLProgram.cpp	(revision 7952)
+++ src/gpu/gl/GrGLProgram.cpp	(working copy)
@@ -125,6 +125,7 @@
         desc->fDiscardIfOutsideEdge = false;
     }
 
+    desc->fEffectAttributes.reset();
     for (int s = 0; s < GrDrawState::kNumStages; ++s) {
 
         bool skip = s < drawState.getFirstCoverageStage() ? skipColor : skipCoverage;
@@ -133,6 +134,14 @@
             const GrEffectRef& effect = *drawState.getStage(s).getEffect();
             const GrBackendEffectFactory& factory = effect->getFactory();
             desc->fEffectKeys[s] = factory.glEffectKey(drawState.getStage(s), gpu->glCaps());
+            int attrCount = drawState.getStage(s).getVertexAttribIndexCount();
+            GrAssert(attrCount == effect.get()->numVertexAttribs());
+            for (int i = 0; i < attrCount; ++i) {
+                Desc::AttribPair pair;
+                pair.fIndex = drawState.getStage(s).getVertexAttribIndices()[i];
+                pair.fName = effect.get()->vertexAttribName(i);
+                desc->fEffectAttributes.push_back(pair);
+            }
         } else {
             desc->fEffectKeys[s] = 0;
         }
@@ -462,13 +471,6 @@
             builder->fFSCode.appendf("\tfloat innerAlpha = %s.w == 0.0 ? 1.0 : smoothstep(%s.w - 0.5, %s.w + 0.5, d);\n", fsName, fsName, fsName);
             builder->fFSCode.append("\tedgeAlpha = outerAlpha * innerAlpha;\n");
             break;
-        case GrDrawState::kEllipse_EdgeType:
-            builder->fFSCode.append("\tfloat edgeAlpha;\n");
-            builder->fFSCode.appendf("\tvec2 offset = (%s.xy - %s.xy);\n", builder->fragmentPosition(), fsName);
-            builder->fFSCode.appendf("\toffset.y *= %s.w;\n", fsName);
-            builder->fFSCode.append("\tfloat d = length(offset);\n");
-            builder->fFSCode.appendf("\tedgeAlpha = smoothstep(d - 0.5, d + 0.5, %s.z);\n", fsName);
-            break;
         default:
             GrCrash("Unknown Edge Type!");
             break;
@@ -914,6 +916,11 @@
                     inCoverage = outCoverage;
                 }
             }
+
+            // discard if coverage is zero
+            if (fDesc.fDiscardIfOutsideEdge && !outCoverage.isEmpty()) {
+                builder.fFSCode.appendf("\tif (all(lessThan(%s, vec4(0.0))) {\n\t\tdiscard;\n\t}\n", outCoverage.c_str());
+            }
         }
 
         if (Desc::kNone_DualSrcOutput != fDesc.fDualSrcOutput) {
@@ -1023,6 +1030,13 @@
         GL_CALL(BindAttribLocation(fProgramID, fDesc.fTexCoordAttributeIndex, TEX_ATTR_NAME));
     }
 
+    const Desc::AttribPair* attribEnd = fDesc.fEffectAttributes.end();
+    for (const Desc::AttribPair* attrib = fDesc.fEffectAttributes.begin(); 
+         attrib != attribEnd;
+         ++attrib) {
+        GL_CALL(BindAttribLocation(fProgramID, attrib->fIndex, attrib->fName));
+    }
+
     GL_CALL(LinkProgram(fProgramID));
 
     GrGLint linked = GR_GL_INIT_ZERO;