separate view matrix from rt adjustment

src/gpu/gl/GrGLShaderBuilder.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gl/GrGLShaderBuilder.h"
 #include "gl/GrGLProgram.h"
 #include "gl/GrGLUniformHandle.h"
@@ skipping 739 matching lines @@
         fLocalCoordsVar->set(kVec2f_GrSLType,
                              GrGLShaderVar::kAttribute_TypeModifier,
                              "aLocalCoords");
     } else {
         fLocalCoordsVar = fPositionVar;
     }
 
     const char* viewMName;
     fViewMatrixUniform = this->addUniform(GrGLShaderBuilder::kVertex_Visibility,
                                           kMat33f_GrSLType, "ViewM", &viewMName);
+    const char* rtAdjustName;
+    fRTAdustmentVecUniform = this->addUniform(GrGLShaderBuilder::kVertex_Visibility,
+                                              kVec4f_GrSLType, "rtAdjustment", &rtAdjustName);
 
-    this->vsCodeAppendf("\tvec3 pos3 = %s * vec3(%s, 1);\n"
-                        "\tgl_Position = vec4(pos3.xy, 0, pos3.z);\n",
+    // Transform the position into Skia's device coords.
+    this->vsCodeAppendf("\tvec3 pos3 = %s * vec3(%s, 1);\n",
                         viewMName, fPositionVar->c_str());
 
+    // Transform from Skia's device coords to GL's normalized device coords.
+    this->vsCodeAppendf(
+        "\tgl_Position = vec4(dot(pos3.xz, %s.xy), dot(pos3.yz, %s.zw), 0, pos3.z);\n",
+        rtAdjustName, rtAdjustName);
+
     // we output point size in the GS if present
     if (header.fEmitsPointSize
 #if GR_GL_EXPERIMENTAL_GS
         && !header.fExperimentalGS
 #endif
         ) {
         this->vsCodeAppend("\tgl_PointSize = 1.0;\n");
     }
 
     if (GrGLProgramDesc::kAttribute_ColorInput == header.fColorInput) {
@@ skipping 215 matching lines @@
 
     GrGLPathTexGenProgramEffectsBuilder pathTexGenEffectsBuilder(this,
                                                                  effectCnt);
     this->INHERITED::createAndEmitEffects(&pathTexGenEffectsBuilder,
                                           effectStages,
                                           effectKeys,
                                           effectCnt,
                                           inOutFSColor);
     return pathTexGenEffectsBuilder.finish();
 }