Take GL version and extensions correctly into account when binding functions

ui/gl/gl_context.h

 // 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.
 
 #ifndef UI_GL_GL_CONTEXT_H_
 #define UI_GL_GL_CONTEXT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/gl/gl_share_group.h"
 #include "ui/gl/gl_state_restorer.h"
 #include "ui/gl/gpu_preference.h"
 
 namespace gfx {
 
 class GLSurface;
 class VirtualGLApi;
+struct GLVersionInfo;
 
 // Encapsulates an OpenGL context, hiding platform specific management.
 class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
  public:
   explicit GLContext(GLShareGroup* share_group);
 
   // Initializes the GL context to be compatible with the given surface. The GL
   // context can be made with other surface's of the same type. The compatible
   // surface is only needed for certain platforms like WGL, OSMesa and GLX. It
   // should be specific for all platforms though.
@@ skipping 38 matching lines @@
   virtual void SetSafeToForceGpuSwitch();
 
   // Indicate that the real context switches should unbind the FBO first
   // (For an Android work-around only).
   virtual void SetUnbindFboOnMakeCurrent();
 
   // Returns whether the current context supports the named extension. The
   // context must be current.
   bool HasExtension(const char* name);
 
+  // Returns version info of the underlying GL context. The context must be
+  // current.
+  const GLVersionInfo* GetVersionInfo();
+
   GLShareGroup* share_group();
 
   // Create a GL context that is compatible with the given surface.
   // |share_group|, if non-NULL, is a group of contexts which the
   // internally created OpenGL context shares textures and other resources.
   static scoped_refptr<GLContext> CreateGLContext(
       GLShareGroup* share_group,
       GLSurface* compatible_surface,
       GpuPreference gpu_preference);
 
@@ skipping 14 matching lines @@
   // being released or destroyed.
   void OnReleaseVirtuallyCurrent(GLContext* virtual_context);
 
  protected:
   virtual ~GLContext();
 
   // Sets the GL api to the real hardware API (vs the VirtualAPI)
   static void SetRealGLApi();
   virtual void SetCurrent(GLSurface* surface);
 
-  // Initialize function pointers to extension functions in the GL
-  // implementation. Should be called immediately after this context is made
-  // current.
-  bool InitializeExtensionBindings();
+  // Initialize function pointers to functions where the bound version depends
+  // on GL version or supported extensions. Should be called immediately after
+  // this context is made current.
+  bool InitializeDynamicBindings();
 
   // Returns the last real (non-virtual) GLContext made current.
   static GLContext* GetRealCurrent();
 
+  // Returns the GL version string. The context must be current.
+  virtual std::string GetGLVersion();
+
  private:
   friend class base::RefCounted<GLContext>;
 
   // For GetRealCurrent.
   friend class VirtualGLApi;
 
   scoped_refptr<GLShareGroup> share_group_;
   scoped_ptr<VirtualGLApi> virtual_gl_api_;
   scoped_ptr<GLStateRestorer> state_restorer_;
+  scoped_ptr<GLVersionInfo> version_info_;
 
   DISALLOW_COPY_AND_ASSIGN(GLContext);
 };
 
 class GL_EXPORT GLContextReal : public GLContext {
  public:
   explicit GLContextReal(GLShareGroup* share_group);
 
  protected:
   virtual ~GLContextReal();
 
   virtual void SetCurrent(GLSurface* surface) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GLContextReal);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_CONTEXT_H_