cc: Use highp precision for texture coords if available and needed

cc/output/texture_copier.cc

 // Copyright 2012 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/texture_copier.h"
 
 #include "base/debug/trace_event.h"
 #include "build/build_config.h"
 #include "cc/output/gl_renderer.h"  // For the GLC() macro.
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
@@ skipping 11 matching lines @@
 
   static const float kPositions[4][4] = { { -1, -1, 0, 1 }, { 1, -1, 0, 1 },
                                           { 1, 1, 0, 1 }, { -1, 1, 0, 1 } };
 
   GLC(context_, context_->bindBuffer(GL_ARRAY_BUFFER, position_buffer_));
   GLC(context_,
       context_->bufferData(
           GL_ARRAY_BUFFER, sizeof(kPositions), kPositions, GL_STATIC_DRAW));
   GLC(context_, context_->bindBuffer(GL_ARRAY_BUFFER, 0));
 
-  blit_program_.reset(new BlitProgram(context_));
+  blit_program_.reset(new BlitProgram(context_, TexCoordPrecisionMedium));
+  blit_program_highp_.reset(new BlitProgram(context_, TexCoordPrecisionHigh));
 }
 
 AcceleratedTextureCopier::~AcceleratedTextureCopier() {
   if (blit_program_)
     blit_program_->Cleanup(context_);
+  if (blit_program_highp_)
+    blit_program_highp_->Cleanup(context_);
   if (position_buffer_)
     GLC(context_, context_->deleteBuffer(position_buffer_));
   if (fbo_)
     GLC(context_, context_->deleteFramebuffer(fbo_));
 }
 
 void AcceleratedTextureCopier::CopyTexture(Parameters parameters) {
   TRACE_EVENT0("cc", "TextureCopier::CopyTexture");
 
   GLC(context_, context_->disable(GL_SCISSOR_TEST));
@@ skipping 16 matching lines @@
 
   GLC(context_,
       context_->bindTexture(GL_TEXTURE_2D, parameters.source_texture));
   GLC(context_,
       context_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST));
   GLC(context_,
       context_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST));
 
-  if (!blit_program_->initialized())
-    blit_program_->Initialize(context_, using_bind_uniforms_);
+  TexCoordPrecision texCoordPrecision = TexCoordPrecisionRequired(
+      context_, gfx::Point(parameters.size.width(), parameters.size.height()));
+  if (texCoordPrecision == TexCoordPrecisionHigh) {
+    if (!blit_program_highp_->initialized())
+      blit_program_highp_->Initialize(context_, using_bind_uniforms_);
 
-  // TODO: Use EXT_framebuffer_blit if available.
-  GLC(context_, context_->useProgram(blit_program_->program()));
+    // TODO: Use EXT_framebuffer_blit if available.
+    GLC(context_, context_->useProgram(blit_program_highp_->program()));
+  } else {
+    if (!blit_program_->initialized())
+      blit_program_->Initialize(context_, using_bind_uniforms_);
+
+    // TODO: Use EXT_framebuffer_blit if available.
+    GLC(context_, context_->useProgram(blit_program_->program()));
+  }
+
 
   const int kPositionAttribute = 0;
   GLC(context_, context_->bindBuffer(GL_ARRAY_BUFFER, position_buffer_));
   GLC(context_,
       context_->vertexAttribPointer(
           kPositionAttribute, 4, GL_FLOAT, false, 0, 0));
   GLC(context_, context_->enableVertexAttribArray(kPositionAttribute));
   GLC(context_, context_->bindBuffer(GL_ARRAY_BUFFER, 0));
 
   GLC(context_,
@@ skipping 17 matching lines @@
   GLC(context_, context_->bindTexture(GL_TEXTURE_2D, 0));
 
   GLC(context_, context_->enable(GL_SCISSOR_TEST));
 }
 
 void AcceleratedTextureCopier::Flush() {
   GLC(context_, context_->flush());
 }
 
 }  // namespace cc