A step in making it possible for WebGL to request no features

and the add them in as extensions are enabled.

The idea is when WebGL inits it's context it will pass ""
to FeatureInfo::Initialize.  After that it can pass various
GL extension strings to FeatureInfo::AddFeatures
to turn on more features.

It can then call glGetString(GL_EXTENSIONS) to see if the
feature was turned on.

Questions: I started this CL trying to make it possible
so each context could have it's own FeatureInfo. I decided
against that. So that brings up the question, should I 
get rid of FeatureInfo and just put this stuff back on
ContextGroup or leave it as is?

If I leave it as is, should I move all the max_XXX stuff
on ContextGroup to FeatureInfo?

TEST=unit tests
BUG=none

Review URL: http://codereview.chromium.org/3413038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@61114 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 185 deletions

diff --git a/gpu/command_buffer/service/context_group.cc b/gpu/command_buffer/service/context_group.cc
index 358e149..c2c9c1f 100644
--- a/gpu/command_buffer/service/context_group.cc
+++ b/gpu/command_buffer/service/context_group.cc
@@ -43,189 +43,19 @@ static void GetIntegerv(GLenum pname, uint32* var) {
   *var = value;
 }
 
-bool ContextGroup::Initialize() {
-  if (initialized_) {
-    return true;
-  }
-
-  // Figure out what extensions to turn on.
-  const char* extensions =
-      reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS));
-  bool npot_ok = false;
-
-  AddExtensionString("GL_CHROMIUM_map_sub");
-
-  // Check if we should allow GL_EXT_texture_compression_dxt1 and
-  // GL_EXT_texture_compression_s3tc.
-  bool enable_dxt1 = false;
-  bool enable_s3tc = false;
 
-  if (strstr(extensions, "GL_EXT_texture_compression_dxt1")) {
-    enable_dxt1 = true;
-  }
-  if (strstr(extensions, "GL_EXT_texture_compression_s3tc")) {
-    enable_dxt1 = true;
-    enable_s3tc = true;
-  }
-
-  if (enable_dxt1) {
-    AddExtensionString("GL_EXT_texture_compression_dxt1");
-    validators_.compressed_texture_format.AddValue(
-        GL_COMPRESSED_RGB_S3TC_DXT1_EXT);
-    validators_.compressed_texture_format.AddValue(
-        GL_COMPRESSED_RGBA_S3TC_DXT1_EXT);
-  }
-
-  if (enable_s3tc) {
-    AddExtensionString("GL_EXT_texture_compression_s3tc");
-    validators_.compressed_texture_format.AddValue(
-        GL_COMPRESSED_RGBA_S3TC_DXT3_EXT);
-    validators_.compressed_texture_format.AddValue(
-        GL_COMPRESSED_RGBA_S3TC_DXT5_EXT);
-  }
 
-  // Check if we should enable GL_EXT_texture_filter_anisotropic.
-  if (strstr(extensions, "GL_EXT_texture_filter_anisotropic")) {
-    AddExtensionString("GL_EXT_texture_filter_anisotropic");
-    validators_.texture_parameter.AddValue(
-        GL_TEXTURE_MAX_ANISOTROPY_EXT);
-    validators_.g_l_state.AddValue(
-        GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT);
-  }
-
-  // Check if we should support GL_OES_packed_depth_stencil and/or
-  // GL_GOOGLE_depth_texture.
-  // NOTE: GL_OES_depth_texture requires support for depth
-  // cubemaps. GL_ARB_depth_texture requires other features that
-  // GL_OES_packed_depth_stencil does not provide. Therefore we made up
-  // GL_GOOGLE_depth_texture.
-  bool enable_depth_texture = false;
-  if (strstr(extensions, "GL_ARB_depth_texture") ||
-      strstr(extensions, "GL_OES_depth_texture")) {
-    enable_depth_texture = true;
-    AddExtensionString("GL_GOOGLE_depth_texture");
-    validators_.texture_internal_format.AddValue(GL_DEPTH_COMPONENT);
-    validators_.texture_format.AddValue(GL_DEPTH_COMPONENT);
-    validators_.pixel_type.AddValue(GL_UNSIGNED_SHORT);
-    validators_.pixel_type.AddValue(GL_UNSIGNED_INT);
-  }
-  // TODO(gman): Add depth types fo ElementsPerGroup and BytesPerElement
-
-  if (strstr(extensions, "GL_EXT_packed_depth_stencil") ||
-      strstr(extensions, "GL_OES_packed_depth_stencil")) {
-    AddExtensionString("GL_OES_packed_depth_stencil");
-    if (enable_depth_texture) {
-      validators_.texture_internal_format.AddValue(GL_DEPTH_STENCIL);
-      validators_.texture_format.AddValue(GL_DEPTH_STENCIL);
-      validators_.pixel_type.AddValue(GL_UNSIGNED_INT_24_8);
-    }
-    validators_.render_buffer_format.AddValue(GL_DEPTH24_STENCIL8);
-  }
-
-  bool enable_texture_format_bgra8888 = false;
-  bool enable_read_format_bgra = false;
-  // Check if we should allow GL_EXT_texture_format_BGRA8888
-  if (strstr(extensions, "GL_EXT_texture_format_BGRA8888") ||
-      strstr(extensions, "GL_APPLE_texture_format_BGRA8888")) {
-    enable_texture_format_bgra8888 = true;
-  }
-
-  if (strstr(extensions, "GL_EXT_bgra")) {
-    enable_texture_format_bgra8888 = true;
-    enable_read_format_bgra = true;
-  }
-
-  if (strstr(extensions, "GL_EXT_read_format_bgra")) {
-    enable_read_format_bgra = true;
-  }
-
-  if (enable_texture_format_bgra8888) {
-    AddExtensionString("GL_EXT_texture_format_BGRA8888");
-    validators_.texture_internal_format.AddValue(GL_BGRA_EXT);
-    validators_.texture_format.AddValue(GL_BGRA_EXT);
-  }
-
-  if (enable_read_format_bgra) {
-    AddExtensionString("GL_EXT_read_format_bgra");
-    validators_.read_pixel_format.AddValue(GL_BGRA_EXT);
-  }
-
-  // Check if we should allow GL_OES_texture_npot
-  if (strstr(extensions, "GL_ARB_texture_non_power_of_two") ||
-      strstr(extensions, "GL_OES_texture_npot")) {
-    AddExtensionString("GL_OES_texture_npot");
-    npot_ok = true;
-  }
-
-  // Check if we should allow GL_OES_texture_float, GL_OES_texture_half_float,
-  // GL_OES_texture_float_linear, GL_OES_texture_half_float_linear
-  bool enable_texture_float = false;
-  bool enable_texture_float_linear = false;
-  bool enable_texture_half_float = false;
-  bool enable_texture_half_float_linear = false;
-  if (strstr(extensions, "GL_ARB_texture_float")) {
-    enable_texture_float = true;
-    enable_texture_float_linear = true;
-    enable_texture_half_float = true;
-    enable_texture_half_float_linear = true;
-  } else {
-    if (strstr(extensions, "GL_OES_texture_float")) {
-      enable_texture_float = true;
-      if (strstr(extensions, "GL_OES_texture_float_linear")) {
-        enable_texture_float_linear = true;
-      }
-    }
-    if (strstr(extensions, "GL_OES_texture_half_float")) {
-      enable_texture_half_float = true;
-      if (strstr(extensions, "GL_OES_texture_half_float_linear")) {
-        enable_texture_half_float_linear = true;
-      }
-    }
-  }
-
-  if (enable_texture_float) {
-    validators_.pixel_type.AddValue(GL_FLOAT);
-    AddExtensionString("GL_OES_texture_float");
-    if (enable_texture_float_linear) {
-      AddExtensionString("GL_OES_texture_float_linear");
-    }
-  }
-
-  if (enable_texture_half_float) {
-    validators_.pixel_type.AddValue(GL_HALF_FLOAT_OES);
-    AddExtensionString("GL_OES_texture_half_float");
-    if (enable_texture_half_float_linear) {
-      AddExtensionString("GL_OES_texture_half_float_linear");
-    }
-  }
-
-  // Check for multisample support
-  if (strstr(extensions, "GL_EXT_framebuffer_multisample")) {
-    extension_flags_.ext_framebuffer_multisample = true;
-    validators_.frame_buffer_target.AddValue(GL_READ_FRAMEBUFFER_EXT);
-    validators_.frame_buffer_target.AddValue(GL_DRAW_FRAMEBUFFER_EXT);
-    validators_.g_l_state.AddValue(GL_READ_FRAMEBUFFER_BINDING_EXT);
-    validators_.render_buffer_parameter.AddValue(GL_MAX_SAMPLES_EXT);
-    AddExtensionString("GL_EXT_framebuffer_multisample");
-    AddExtensionString("GL_EXT_framebuffer_blit");
-  }
-
-  if (strstr(extensions, "GL_OES_depth24") ||
-      gfx::GetGLImplementation() == gfx::kGLImplementationDesktopGL) {
-    AddExtensionString("GL_OES_depth24");
-    validators_.render_buffer_format.AddValue(GL_DEPTH_COMPONENT24);
+bool ContextGroup::Initialize(const char* allowed_features) {
+  if (initialized_) {
+    return true;
   }
 
-  if (strstr(extensions, "GL_OES_standard_derivatives") ||
-      gfx::GetGLImplementation() == gfx::kGLImplementationDesktopGL) {
-    AddExtensionString("GL_OES_standard_derivatives");
-    extension_flags_.oes_standard_derivatives = true;
+  if (!feature_info_.Initialize(allowed_features)) {
+    LOG(ERROR) << "ContextGroup::Initialize failed because FeatureInfo "
+               << "initialization failed.";
+    return false;
   }
 
-  // TODO(gman): Add support for these extensions.
-  //     GL_OES_depth32
-  //     GL_OES_element_index_uint
-
   buffer_manager_.reset(new BufferManager());
   framebuffer_manager_.reset(new FramebufferManager());
   renderbuffer_manager_.reset(new RenderbufferManager());
@@ -253,10 +83,7 @@ bool ContextGroup::Initialize() {
   GLint max_cube_map_texture_size;
   glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max_texture_size);
   glGetIntegerv(GL_MAX_CUBE_MAP_TEXTURE_SIZE, &max_cube_map_texture_size);
-  texture_manager_.reset(new TextureManager(npot_ok,
-                                            enable_texture_float_linear,
-                                            enable_texture_half_float_linear,
-                                            max_texture_size,
+  texture_manager_.reset(new TextureManager(max_texture_size,
                                             max_cube_map_texture_size));
 
   GetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &max_texture_image_units_);
@@ -320,10 +147,6 @@ void ContextGroup::Destroy(bool have_context) {
   }
 }
 
-void ContextGroup::AddExtensionString(const std::string& str) {
-  extensions_ += (extensions_.empty() ? "" : " ") + str;
-}
-
 IdAllocator* ContextGroup::GetIdAllocator(unsigned namespace_id) {
   IdAllocatorMap::iterator it = id_namespaces_.find(namespace_id);
   if (it != id_namespaces_.end()) {