Virtual GL

ui/gl/gl_gl_api_implementation.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_API_IMPLEMENTATION_H_
 #define UI_GL_GL_API_IMPLEMENTATION_H_
 
 #include "base/compiler_specific.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_export.h"
 
+namespace gpu {
+namespace gles2 {
+class GLES2Decoder;
+}
+}
 namespace gfx {
 
 class GLContext;
+class GLSurface;
 
 void InitializeGLBindingsGL();
 void InitializeGLExtensionBindingsGL(GLContext* context);
 void InitializeDebugGLBindingsGL();
 void ClearGLBindingsGL();
+void SetGLToRealGLApi();
+void SetGLApi(GLApi* api);
 
+// Implemenents the GL API by calling directly into the driver.
 class GL_EXPORT RealGLApi : public GLApi {
  public:
   RealGLApi();
+  virtual ~RealGLApi();
   void Initialize(DriverGL* driver);
 
   // Include the auto-generated part of this class. We split this because
   // it means we can easily edit the non-auto generated parts right here in
   // this file instead of having to edit some template or the code generator.
   #include "gl_bindings_api_autogen_gl.h"
 
  private:
   DriverGL* driver_;
 };
 
+// Implementents the GL API using co-operative state restoring.
+// Assumes there is only one real GL context and that multiple virtual contexts
+// are implemented above it. Restores the needed state from the current context.
+class GL_EXPORT VirtualGLApi : public GLApi {
+ public:
+  VirtualGLApi();
+  virtual ~VirtualGLApi();
+  void Initialize(DriverGL* driver, GLContext* real_context);
+
+  // Include the auto-generated part of this class. We split this because
+  // it means we can easily edit the non-auto generated parts right here in
+  // this file instead of having to edit some template or the code generator.
+  #undef UI_GFX_GL_GL_BINDINGS_API_AUTOGEN_GL_H_

[apatrick_chromium, 2012/11/05 20:50:44]

If gl_bindings_api_autogen.h is intended to be used this way, maybe it doesn't
want a sentry ifdef and then this undef can go away.

[greggman, 2012/11/06 02:56:37]

Done.

+  #include "gl_bindings_api_autogen_gl.h"
+
+  // Sets the current virutal context.
+  bool MakeCurrent(GLContext* virtual_context, GLSurface* surface);
+
+ private:
+  DriverGL* driver_;
+
+  // The real context we're running on.
+  GLContext* real_context_;
+
+  // The current virtual context.
+  GLContext* current_context_;
+
+  // The current surface.
+  GLSurface* current_surface_;
+};
+
 }  // namespace gfx
 
 #endif  // UI_GL_GL_API_IMPLEMENTATION_H_