Enable vertexless shading when path rendering is supported

src/gpu/gl/GrGLEffectMatrix.cpp

Index: src/gpu/gl/GrGLEffectMatrix.cpp
diff --git a/src/gpu/gl/GrGLEffectMatrix.cpp b/src/gpu/gl/GrGLEffectMatrix.cpp
index ef3812e0fbb7c87e9f4ef4b243a613cfaafd7515..9c333cd2d06c1e25357e459706f3d698c6879f9b 100644
--- a/src/gpu/gl/GrGLEffectMatrix.cpp
+++ b/src/gpu/gl/GrGLEffectMatrix.cpp
@@ -48,10 +48,6 @@ GrSLType GrGLEffectMatrix::emitCode(GrGLShaderBuilder* builder,
                                     SkString* fsCoordName,
                                     SkString* vsCoordName,
                                     const char* suffix) {
-    // TODO: Handle vertexless shaders here before we start enabling them.
-    GrGLShaderBuilder::VertexBuilder* vertexBuilder = builder->getVertexBuilder();
-    SkASSERT(NULL != vertexBuilder);
-
     GrSLType varyingType = kVoid_GrSLType;
     const char* uniName;
     key &= kKeyMask;
@@ -78,6 +74,16 @@ GrSLType GrGLEffectMatrix::emitCode(GrGLShaderBuilder* builder,
         default:
             GrCrash("Unexpected key.");
     }
+
+    GrGLShaderBuilder::VertexBuilder* vertexBuilder = builder->getVertexBuilder();
+    if (NULL == vertexBuilder) {
+        if (vsCoordName) {
+            vsCoordName->reset();
+        }
+        builder->addTexGenUnit(varyingType, fsCoordName, &fTexGenUnit, &fNumTexGenComponents);
+        return varyingType;
+    }
+
     SkString suffixedUniName;
     if (NULL != suffix) {
         suffixedUniName.append(uniName);
@@ -193,7 +199,7 @@ void GrGLEffectMatrix::setData(const GrGLUniformManager& uniformManager,
                                const SkMatrix& matrix,
                                const GrDrawEffect& drawEffect,
                                const GrTexture* texture) {
-    SkASSERT(fUni.isValid() != (kVoid_GrSLType == fUniType));
+    SkASSERT(fUni.isValid() != (fTexGenUnit >= 0 || kVoid_GrSLType == fUniType));
     const SkMatrix& coordChangeMatrix = GrEffect::kLocal_CoordsType == fCoordsType ?
                                             drawEffect.getCoordChangeMatrix() :
                                             SkMatrix::I();
@@ -202,14 +208,25 @@ void GrGLEffectMatrix::setData(const GrGLUniformManager& uniformManager,
             SkASSERT(matrix.isIdentity());
             SkASSERT(coordChangeMatrix.isIdentity());
             SkASSERT(NULL == texture || kTopLeft_GrSurfaceOrigin == texture->origin());
+            if (fTexGenUnit >= 0) {
+                SkASSERT(fNumTexGenComponents == 2);
+                GrGLfloat texgenCoefficients[] = {1, 0, 0,
+                                                  0, 1, 0};
+                uniformManager.enableGlobalTexGen(fTexGenUnit, 2, texgenCoefficients);
+            }
             return;
         case kVec2f_GrSLType: {
             SkASSERT(SkMatrix::kTranslate_Mask == (matrix.getType() | coordChangeMatrix.getType()));
             SkASSERT(NULL == texture || kTopLeft_GrSurfaceOrigin == texture->origin());
             SkScalar tx = matrix[SkMatrix::kMTransX] + (coordChangeMatrix)[SkMatrix::kMTransX];
             SkScalar ty = matrix[SkMatrix::kMTransY] + (coordChangeMatrix)[SkMatrix::kMTransY];
-            if (fPrevMatrix.get(SkMatrix::kMTransX) != tx ||
-                fPrevMatrix.get(SkMatrix::kMTransY) != ty) {
+            if (fTexGenUnit >= 0) {
+                SkASSERT(fNumTexGenComponents == 2);
+                GrGLfloat texgenCoefficients[] = {1, 0, SkScalarToFloat(tx),
+                                                  0, 1, SkScalarToFloat(ty)};
+                uniformManager.enableGlobalTexGen(fTexGenUnit, 2, texgenCoefficients);
+            } else if (fPrevMatrix.get(SkMatrix::kMTransX) != tx ||
+                       fPrevMatrix.get(SkMatrix::kMTransY) != ty) {
                 uniformManager.set2f(fUni, tx, ty);
                 fPrevMatrix.set(SkMatrix::kMTransX, tx);
                 fPrevMatrix.set(SkMatrix::kMTransY, ty);
@@ -229,7 +246,9 @@ void GrGLEffectMatrix::setData(const GrGLUniformManager& uniformManager,
                 combined.set(SkMatrix::kMTransY,
                     combined[SkMatrix::kMPersp2] - combined[SkMatrix::kMTransY]);
             }
-            if (!fPrevMatrix.cheapEqualTo(combined)) {
+            if (fTexGenUnit >= 0) {
+                uniformManager.enableGlobalTexGen(fTexGenUnit, fNumTexGenComponents, combined);
+            } else if (!fPrevMatrix.cheapEqualTo(combined)) {
                 uniformManager.setSkMatrix(fUni, combined);
                 fPrevMatrix = combined;
             }