separate view matrix from rt adjustment

src/gpu/gl/GrGLProgram.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrGLProgram_DEFINED
 #define GrGLProgram_DEFINED
@@ skipping 85 matching lines @@
         SkISize         fRenderTargetSize;
         GrSurfaceOrigin fRenderTargetOrigin;
 
         MatrixState() { this->invalidate(); }
         void invalidate() {
             fViewMatrix = SkMatrix::InvalidMatrix();
             fRenderTargetSize.fWidth = -1;
             fRenderTargetSize.fHeight = -1;
             fRenderTargetOrigin = (GrSurfaceOrigin) -1;
         }
+
+        /**
+         * Gets a matrix that goes from local coords to Skia's device coordinates.
+         */
         template<int Size> void getGLMatrix(GrGLfloat* destMatrix) {
+            GrGLGetMatrix<Size>(destMatrix, fViewMatrix);
+        }
+
+        /**
+         * Gets a matrix that goes from local coordinates to GL normalized device coords.
+         */
+        template<int Size> void getRTAdjustedGLMatrix(GrGLfloat* destMatrix) {
             SkMatrix combined;
             if (kBottomLeft_GrSurfaceOrigin == fRenderTargetOrigin) {
                 combined.setAll(SkIntToScalar(2) / fRenderTargetSize.fWidth, 0, -SK_Scalar1,
                                 0, -SkIntToScalar(2) / fRenderTargetSize.fHeight, SK_Scalar1,
-                                0, 0, SkMatrix::I()[8]);
+                                0, 0, 1);
             } else {
                 combined.setAll(SkIntToScalar(2) / fRenderTargetSize.fWidth, 0, -SK_Scalar1,
                                 0, SkIntToScalar(2) / fRenderTargetSize.fHeight, -SK_Scalar1,
-                                0, 0, SkMatrix::I()[8]);
+                                0, 0, 1);
             }
             combined.preConcat(fViewMatrix);
             GrGLGetMatrix<Size>(destMatrix, combined);
         }
+
+        /**
+         * Gets a vec4 that adjusts the position from Skia device coords to GL's normalized device
+         * coords. Assuming the transformed position, pos, is a homogeneous vec3, the vec, v, is
+         * applied as such:
+         * pos.x = dot(v.xy, pos.xz)
+         * pos.y = dot(v.zq, pos.yz)
+         */
+        void getRTAdjustmentVec(GrGLfloat* destVec) {
+            destVec[0] = 2.f / fRenderTargetSize.fWidth;
+            destVec[1] = -1.f;
+            if (kBottomLeft_GrSurfaceOrigin == fRenderTargetOrigin) {
+                destVec[2] = -2.f / fRenderTargetSize.fHeight;
+                destVec[3] = 1.f;
+            } else {
+                destVec[2] = 2.f / fRenderTargetSize.fHeight;
+                destVec[3] = -1.f;
+            }
+        }
     };
 
     /**
      * This function uploads uniforms and calls each GrGLEffect's setData. It is called before a
      * draw occurs using the program after the program has already been bound. It also uses the
      * GrGpuGL object to bind the textures required by the GrGLEffects. The color and coverage
      * stages come from GrGLProgramDesc::Build().
      */
     void setData(GrDrawState::BlendOptFlags,
                  const GrEffectStage* colorStages[],
                  const GrEffectStage* coverageStages[],
                  const GrDeviceCoordTexture* dstCopy, // can be NULL
                  SharedGLState*);
 
 private:
     typedef GrGLUniformManager::UniformHandle UniformHandle;
 
     // handles for uniforms (aside from per-effect samplers)
     struct UniformHandles {
         UniformHandle       fViewMatrixUni;
+        UniformHandle       fRTAdjustmentUni;
         UniformHandle       fColorUni;
         UniformHandle       fCoverageUni;
 
         // We use the render target height to provide a y-down frag coord when specifying
         // origin_upper_left is not supported.
         UniformHandle       fRTHeightUni;
 
         // Uniforms for computing texture coords to do the dst-copy lookup
         UniformHandle       fDstCopyTopLeftUni;
         UniformHandle       fDstCopyScaleUni;
@@ skipping 47 matching lines @@
     GrGLUniformManager                fUniformManager;
     UniformHandles                    fUniformHandles;
 
     bool                              fHasVertexShader;
     int                               fNumTexCoordSets;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif