Delete useless codes in gles2_cmd_copy_texture_chromium

gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc

 // Copyright (c) 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 "gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 348 matching lines @@
         source += "#extension GL_NV_EGL_stream_consumer_external : enable\n";
       }
     }
   } else {
     source += "#version 150\n";
   }
 
   // Preamble for texture precision.
   source += kShaderPrecisionPreamble;
 
-  if (gpu::gles2::GLES2Util::IsSignedIntegerFormat(dest_format)) {
-    source += "#define TextureType ivec4\n";
-    source += "#define ZERO 0\n";
-    source += "#define MAX_COLOR 255\n";
-    if (gpu::gles2::GLES2Util::IsSignedIntegerFormat(source_format))
-      source += "#define InnerScaleValue 1\n";
-    else if (gpu::gles2::GLES2Util::IsUnsignedIntegerFormat(source_format))
-      source += "#define InnerScaleValue 1u\n";
-    else
-      source += "#define InnerScaleValue 255.0\n";
-    source += "#define OuterScaleValue 1\n";
-  } else if (gpu::gles2::GLES2Util::IsUnsignedIntegerFormat(dest_format)) {
+  // According to the spec, |dest_format| can be unsigend interger format, float
+  // format or unsigned normalized fixed-point format. |source_format| can only
+  // be unsigned normalized fixed-point format.
+  if (gpu::gles2::GLES2Util::IsUnsignedIntegerFormat(dest_format)) {
     source += "#define TextureType uvec4\n";
     source += "#define ZERO 0u\n";
     source += "#define MAX_COLOR 255u\n";
-    if (gpu::gles2::GLES2Util::IsSignedIntegerFormat(source_format))
-      source += "#define InnerScaleValue 1\n";
-    else if (gpu::gles2::GLES2Util::IsUnsignedIntegerFormat(source_format))
-      source += "#define InnerScaleValue 1u\n";
-    else
-      source += "#define InnerScaleValue 255.0\n";
+    source += "#define InnerScaleValue 255.0\n";
     source += "#define OuterScaleValue 1u\n";
   } else {

[Zhenyao Mo, 2017/05/12 18:00:44]

Can we add a DCHECK here to make sure we only get float or fixed point formats
here?

[jiajia.qin, 2017/05/15 01:42:11]

Done. I use DCHECK(!gpu::gles2::GLES2Util::IsIntegerFormat(dest_format)). I
didn't find a function IsFixedPointFormat or similar function. So do we need to
add this function and use DCHECK(isFloadFormat || IsUnsignedFixedPointFormat )
here or DCHECK(!IsIntegerFormat) is enough?

     source += "#define TextureType vec4\n";
     source += "#define ZERO 0.0\n";
     source += "#define MAX_COLOR 1.0\n";
-    if (gpu::gles2::GLES2Util::IsSignedIntegerFormat(source_format)) {
-      source += "#define InnerScaleValue 1\n";
-      source += "#define OuterScaleValue (1.0 / 255.0)\n";
-    } else if (gpu::gles2::GLES2Util::IsUnsignedIntegerFormat(source_format)) {
-      source += "#define InnerScaleValue 1u\n";
-      source += "#define OuterScaleValue (1.0 / 255.0)\n";
-    } else {
-      source += "#define InnerScaleValue 1.0\n";
-      source += "#define OuterScaleValue 1.0\n";
-    }
+    source += "#define InnerScaleValue 1.0\n";
+    source += "#define OuterScaleValue 1.0\n";
   }
   if (gl_version_info.is_es2 || gl_version_info.IsLowerThanGL(3, 2) ||
       target == GL_TEXTURE_EXTERNAL_OES) {
     switch (target) {
       case GL_TEXTURE_2D:
       case GL_TEXTURE_EXTERNAL_OES:
         source += "#define TextureLookup texture2D\n";
         break;
       default:
         NOTREACHED();
@@ skipping 933 matching lines @@
   decoder->RestoreTextureUnitBindings(0);
   decoder->RestoreActiveTexture();
   decoder->RestoreProgramBindings();
   decoder->RestoreBufferBindings();
   decoder->RestoreFramebufferBindings();
   decoder->RestoreGlobalState();
 }
 
 }  // namespace gles2
 }  // namespace gpu