Revert of Multi-string shaders

src/gpu/gl/builders/GrGLGeometryShaderBuilder.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 "GrGLGeometryShaderBuilder.h"
+#include "GrGLShaderStringBuilder.h"
 #include "GrGLProgramBuilder.h"
 #include "../GrGLGpu.h"
 
 GrGLGeometryBuilder::GrGLGeometryBuilder(GrGLProgramBuilder* program)
     : INHERITED(program) {
 
 }
 
 void GrGLGeometryBuilder::addVarying(const char* name, GrGLVarying* v) {
     // if we have a GS take each varying in as an array
@@ skipping 10 matching lines @@
     if (v->fsVarying()) {
         fOutputs.push_back();
         fOutputs.back().setType(v->fType);
         fOutputs.back().setTypeModifier(GrGLShaderVar::kVaryingOut_TypeModifier);
         fProgramBuilder->nameVariable(fOutputs.back().accessName(), 'g', name);
         v->fGsOut = fOutputs.back().getName().c_str();
     }
 }
 
 bool GrGLGeometryBuilder::compileAndAttachShaders(GrGLuint programId,
-        SkTDArray<GrGLuint>* shaderIds) {
-    SkFAIL("Geometry shaders are not currently supported");
-    return false;
+        SkTDArray<GrGLuint>* shaderIds) const {
+    const GrGLContext& glCtx = fProgramBuilder->gpu()->glContext();
+    SkASSERT(fProgramBuilder->ctxInfo().glslGeneration() >= k150_GrGLSLGeneration);
+    SkString geomShaderSrc(GrGetGLSLVersionDecl(fProgramBuilder->ctxInfo()));
+    geomShaderSrc.append("layout(triangles) in;\n"
+                         "layout(triangle_strip, max_vertices = 6) out;\n");
+    this->appendDecls(fInputs, &geomShaderSrc);
+    this->appendDecls(fOutputs, &geomShaderSrc);
+    geomShaderSrc.append("void main() {\n");
+    geomShaderSrc.append("\tfor (int i = 0; i < 3; ++i) {\n"
+                         "\t\tgl_Position = gl_in[i].gl_Position;\n");
+    geomShaderSrc.append("\t\tgl_PointSize = 1.0;\n");
+    SkASSERT(fInputs.count() == fOutputs.count());
+    for (int i = 0; i < fInputs.count(); ++i) {
+        geomShaderSrc.appendf("\t\t%s = %s[i];\n",
+                              fOutputs[i].getName().c_str(),
+                              fInputs[i].getName().c_str());
+    }
+    geomShaderSrc.append("\t\tEmitVertex();\n"
+                         "\t}\n"
+                         "\tEndPrimitive();\n");
+    geomShaderSrc.append("}\n");
+    GrGLuint geomShaderId =
+        GrGLCompileAndAttachShader(glCtx, programId,
+                                   GR_GL_GEOMETRY_SHADER, geomShaderSrc,
+                                   fProgramBuilder->gpu()->stats());
+    if (!geomShaderId) {
+        return false;
+    }
+    *shaderIds->append() = geomShaderId;
+    return true;
 }