Take GL version and extensions correctly into account when binding functions

ui/gl/gl_implementation_win.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 <vector>
 
 #include "base/at_exit.h"
 #include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/native_library.h"
 #include "base/path_service.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/win/windows_version.h"
 #include "ui/gl/gl_bindings.h"
+#include "ui/gl/gl_context_stub_with_extensions.h"
 #include "ui/gl/gl_egl_api_implementation.h"
 #include "ui/gl/gl_gl_api_implementation.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_osmesa_api_implementation.h"
+#include "ui/gl/gl_surface_wgl.h"
 #include "ui/gl/gl_wgl_api_implementation.h"
 
 #if defined(ENABLE_SWIFTSHADER)
 #include "software_renderer.h"
 #endif
 
 namespace gfx {
 
 namespace {
 
@@ skipping 65 matching lines @@
     AddTraceEventFunc add_trace_event_func);
 
 }  // namespace
 
 void GetAllowedGLImplementations(std::vector<GLImplementation>* impls) {
   impls->push_back(kGLImplementationEGLGLES2);
   impls->push_back(kGLImplementationDesktopGL);
   impls->push_back(kGLImplementationOSMesaGL);
 }
 
-bool InitializeGLBindings(GLImplementation implementation) {
+bool InitializeStaticGLBindings(GLImplementation implementation) {
   // Prevent reinitialization with a different implementation. Once the gpu
   // unit tests have initialized with kGLImplementationMock, we don't want to
   // later switch to another GL implementation.
   if (GetGLImplementation() != kGLImplementationNone)
     return true;
 
   // Allow the main thread or another to initialize these bindings
   // after instituting restrictions on I/O. Going forward they will
   // likely be used in the browser process on most platforms. The
   // one-time initialization cost is small, between 2 and 5 ms.
@@ skipping 21 matching lines @@
       if (!get_proc_address) {
         DLOG(ERROR) << "OSMesaGetProcAddress not found.";
         base::UnloadNativeLibrary(library);
         return false;
       }
 
       SetGLGetProcAddressProc(get_proc_address);
       AddGLNativeLibrary(library);
       SetGLImplementation(kGLImplementationOSMesaGL);
 
-      InitializeGLBindingsGL();
-      InitializeGLBindingsOSMESA();
+      InitializeStaticGLBindingsGL();
+      InitializeStaticGLBindingsOSMESA();
       break;
     }
     case kGLImplementationEGLGLES2: {
       base::FilePath module_path;
       if (!PathService::Get(base::DIR_MODULE, &module_path))
         return false;
 
       // Attempt to load the D3DX shader compiler using the default search path
       // and if that fails, using an absolute path. This is to ensure these DLLs
       // are loaded before ANGLE is loaded in case they are not in the default
@@ skipping 64 matching lines @@
         base::UnloadNativeLibrary(egl_library);
         base::UnloadNativeLibrary(gles_library);
         return false;
       }
 
       SetGLGetProcAddressProc(get_proc_address);
       AddGLNativeLibrary(egl_library);
       AddGLNativeLibrary(gles_library);
       SetGLImplementation(kGLImplementationEGLGLES2);
 
-      InitializeGLBindingsGL();
-      InitializeGLBindingsEGL();
+      InitializeStaticGLBindingsGL();
+      InitializeStaticGLBindingsEGL();
 
       // These two functions take single precision float rather than double
       // precision float parameters in GLES.
       ::gfx::g_driver_gl.fn.glClearDepthFn = MarshalClearDepthToClearDepthf;
       ::gfx::g_driver_gl.fn.glDepthRangeFn = MarshalDepthRangeToDepthRangef;
       break;
     }
     case kGLImplementationDesktopGL: {
-      // When using Windows OpenGL, first try wglGetProcAddress and then
-      // Windows GetProcAddress.
       base::NativeLibrary library = base::LoadNativeLibrary(
           base::FilePath(L"opengl32.dll"), NULL);
       if (!library) {
         DVLOG(1) << "opengl32.dll not found";
         return false;
       }
 
       GLGetProcAddressProc get_proc_address =
           reinterpret_cast<GLGetProcAddressProc>(
               base::GetFunctionPointerFromNativeLibrary(
                   library, "wglGetProcAddress"));
       if (!get_proc_address) {
         LOG(ERROR) << "wglGetProcAddress not found.";
         base::UnloadNativeLibrary(library);
         return false;
       }
 
       SetGLGetProcAddressProc(get_proc_address);
       AddGLNativeLibrary(library);
       SetGLImplementation(kGLImplementationDesktopGL);
 
-      InitializeGLBindingsGL();
-      InitializeGLBindingsWGL();
+      // Initialize WGL bindings to be able to create a context.
+      InitializeStaticGLBindingsWGL();
+
+      // Create a temporary GL context to bind to entry points. This is needed
+      // because wglGetProcAddress is specified to return NULL for all queries
+      // if a context is not current in MSDN documentation, and the static
+      // bindings may contain functions that need to be queried with
+      // wglGetProcAddress. OpenGL wiki further warns that other error values
+      // than NULL could also be returned from wglGetProcAddress on some
+      // implementations, so we need to clear the WGL bindings and reinitialize
+      // them after the context creation.
+      HGLRC gl_context = wglCreateContext(GLSurfaceWGL::GetDisplayDC());
+      if (!gl_context) {
+        LOG(ERROR) << "Failed to create temporary context.";
+        return false;
+      }
+      if (!wglMakeCurrent(GLSurfaceWGL::GetDisplayDC(), gl_context)) {
+        LOG(ERROR) << "Failed to make temporary GL context current.";
+        wglDeleteContext(gl_context);
+        return false;
+      }
+
+      ClearGLBindingsWGL();
+      InitializeStaticGLBindingsGL();
+      InitializeStaticGLBindingsWGL();
+
+      wglMakeCurrent(NULL, NULL);
+      wglDeleteContext(gl_context);
+
       break;
     }
     case kGLImplementationMockGL: {
       SetGLGetProcAddressProc(GetMockGLProcAddress);
       SetGLImplementation(kGLImplementationMockGL);
-      InitializeGLBindingsGL();
+      InitializeStaticGLBindingsGL();
       break;
     }
     default:
       return false;
   }
 
   return true;
 }
 
-bool InitializeGLExtensionBindings(GLImplementation implementation,
+bool InitializeDynamicGLBindings(GLImplementation implementation,
     GLContext* context) {
   switch (implementation) {
     case kGLImplementationOSMesaGL:
-      InitializeGLExtensionBindingsGL(context);
-      InitializeGLExtensionBindingsOSMESA(context);
+      InitializeDynamicGLBindingsGL(context);
+      InitializeDynamicGLBindingsOSMESA(context);
       break;
     case kGLImplementationEGLGLES2:
-      InitializeGLExtensionBindingsGL(context);
-      InitializeGLExtensionBindingsEGL(context);
+      InitializeDynamicGLBindingsGL(context);
+      InitializeDynamicGLBindingsEGL(context);
       break;
     case kGLImplementationDesktopGL:
-      InitializeGLExtensionBindingsGL(context);
-      InitializeGLExtensionBindingsWGL(context);
+      InitializeDynamicGLBindingsGL(context);
+      InitializeDynamicGLBindingsWGL(context);
       break;
     case kGLImplementationMockGL:
-      InitializeGLExtensionBindingsGL(context);
+      if (!context) {
+        scoped_refptr<GLContextStubWithExtensions> mock_context(
+            new GLContextStubWithExtensions());
+        mock_context->SetGLVersionString("3.0");
+        InitializeDynamicGLBindingsGL(mock_context.get());
+      } else
+        InitializeDynamicGLBindingsGL(context);
       break;
     default:
       return false;
   }
 
   return true;
 }
 
 void InitializeDebugGLBindings() {
   InitializeDebugGLBindingsEGL();
@@ skipping 17 matching lines @@
       return GetGLWindowSystemBindingInfoWGL(info);
     case kGLImplementationEGLGLES2:
       return GetGLWindowSystemBindingInfoEGL(info);
     default:
       return false;
   }
   return false;
 }
 
 }  // namespace gfx