cc: Support texcoord offsets in YUVVideoDrawQuad

cc/output/shader.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/output/shader.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 167 matching lines @@
     attribute TexCoordPrecision vec2 a_texCoord;
     uniform mat4 matrix;
     varying TexCoordPrecision vec2 v_texCoord;
     void main() {
       gl_Position = matrix * a_position;
       v_texCoord = a_texCoord;
     }
   );  // NOLINT(whitespace/parens)
 }
 
-VertexShaderPosTexYUVStretch::VertexShaderPosTexYUVStretch()
-    : matrix_location_(-1),
-      tex_scale_location_(-1) {}
+VertexShaderPosTexYUVStretchOffset::VertexShaderPosTexYUVStretchOffset()
+    : matrix_location_(-1), tex_scale_location_(-1), tex_offset_location_(-1) {}
 
-void VertexShaderPosTexYUVStretch::Init(GLES2Interface* context,
-                                        unsigned program,
-                                        int* base_uniform_index) {
+void VertexShaderPosTexYUVStretchOffset::Init(GLES2Interface* context,
+                                              unsigned program,
+                                              int* base_uniform_index) {
   static const char* uniforms[] = {
     "matrix",
     "texScale",
+    "texOffset",
   };
   int locations[arraysize(uniforms)];
 
   GetProgramUniformLocations(context,
                              program,
                              arraysize(uniforms),
                              uniforms,
                              locations,
                              base_uniform_index);
   matrix_location_ = locations[0];
   tex_scale_location_ = locations[1];
+  tex_offset_location_ = locations[2];
 }
 
-std::string VertexShaderPosTexYUVStretch::GetShaderString() const {
+std::string VertexShaderPosTexYUVStretchOffset::GetShaderString() const {
   return VERTEX_SHADER(
     precision mediump float;
     attribute vec4 a_position;
     attribute TexCoordPrecision vec2 a_texCoord;
     uniform mat4 matrix;
     varying TexCoordPrecision vec2 v_texCoord;
     uniform TexCoordPrecision vec2 texScale;
+    uniform TexCoordPrecision vec2 texOffset;
     void main() {
         gl_Position = matrix * a_position;
-        v_texCoord = a_texCoord * texScale;
+        v_texCoord = a_texCoord * texScale + texOffset;
     }
   );  // NOLINT(whitespace/parens)
 }
 
 VertexShaderPos::VertexShaderPos()
     : matrix_location_(-1) {}
 
 void VertexShaderPos::Init(GLES2Interface* context,
                            unsigned program,
                            int* base_uniform_index) {
@@ skipping 1297 matching lines @@
       vec2 texCoord =
           clamp(v_texCoord, 0.0, 1.0) * texTransform.zw + texTransform.xy;
       vec2 coord = mod(floor(texCoord * frequency * 2.0), 2.0);
       float picker = abs(coord.x - coord.y);  // NOLINT
       gl_FragColor = mix(color1, color2, picker) * alpha;
     }
   );  // NOLINT(whitespace/parens)
 }
 
 }  // namespace cc