16-bit video upload to float: intermediate R16_EXT and copy to float.

gpu/command_buffer/service/feature_info.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/feature_info.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <vector>
@@ skipping 1275 matching lines @@
     validators_.texture_internal_format.AddValue(GL_RG8_EXT);
     validators_.read_pixel_format.AddValue(GL_RED_EXT);
     validators_.read_pixel_format.AddValue(GL_RG_EXT);
     validators_.render_buffer_format.AddValue(GL_R8_EXT);
     validators_.render_buffer_format.AddValue(GL_RG8_EXT);
     validators_.texture_unsized_internal_format.AddValue(GL_RED_EXT);
     validators_.texture_unsized_internal_format.AddValue(GL_RG_EXT);
   }
   UMA_HISTOGRAM_BOOLEAN("GPU.TextureRG", feature_flags_.ext_texture_rg);
 
+  if (gl_version_info_->is_desktop_core_profile ||
+      extensions.Contains("GL_EXT_texture_norm16")) {
+    feature_flags_.ext_texture_norm16 = true;
+    AddExtensionString("GL_EXT_texture_norm16");
+
+    // Note: EXT_texture_norm16 is not exposed through WebGL API so we validate
+    // only the combinations used internally.
+    validators_.texture_format.AddValue(GL_RED_EXT);
+    validators_.texture_internal_format.AddValue(GL_R16_EXT);
+    validators_.texture_internal_format.AddValue(GL_RED_EXT);
+    validators_.texture_unsized_internal_format.AddValue(GL_RED_EXT);

[Ken Russell (switch to Gerrit), 2017/04/20 01:47:06]

Have you confirmed that these aren't accessible when calling through the WebGL
API? I'm pretty sure that WebGL2RenderingContextBase should catch attempts to
use them.

Could you add a WebGL conformance test under conformance2/textures/misc/ that
tries to allocate textures with these internal formats, and confirms that the
attempts fail?

We also need to make sure that we can't now suddenly allocate unsized GL_RED
textures from WebGL, if GL_R8 is the only legally supported internal format from
the ES3 standpoint.

[aleksandar.stojiljkovic, 2017/04/26 13:29:40]

Thanks.
Done.
https://github.com/KhronosGroup/WebGL/pull/2379

+  }
+
   bool has_opengl_dual_source_blending =
       gl_version_info_->IsAtLeastGL(3, 3) ||
       (gl_version_info_->IsAtLeastGL(3, 2) &&
        extensions.Contains("GL_ARB_blend_func_extended"));
   if (!disable_shader_translator_ &&
       !workarounds_.get_frag_data_info_bug &&
       ((gl_version_info_->IsAtLeastGL(3, 2) &&
         has_opengl_dual_source_blending) ||
        (gl_version_info_->IsAtLeastGLES(3, 0) &&
         extensions.Contains("GL_EXT_blend_func_extended")))) {
@@ skipping 377 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu