ui/gl/gl_context.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_GL_GL_CONTEXT_H_
   6 #define UI_GL_GL_CONTEXT_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "ui/gl/gl_share_group.h"
  14 #include "ui/gl/gpu_preference.h"
  15
  16 namespace gfx {
  17
  18 class GLSurface;
  19 class VirtualGLApi;
  20 class GLStateRestorer;
  21
  22 // Encapsulates an OpenGL context, hiding platform specific management.
  23 class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
  24  public:
  25   explicit GLContext(GLShareGroup* share_group);
  26
  27   // Initializes the GL context to be compatible with the given surface. The GL
  28   // context can be made with other surface's of the same type. The compatible
  29   // surface is only needed for certain platforms like WGL, OSMesa and GLX. It
  30   // should be specific for all platforms though.
  31   virtual bool Initialize(
  32       GLSurface* compatible_surface, GpuPreference gpu_preference) = 0;
  33
  34   // Destroys the GL context.
  35   virtual void Destroy() = 0;
  36
  37   // Makes the GL context and a surface current on the current thread.
  38   virtual bool MakeCurrent(GLSurface* surface) = 0;
  39
  40   // Releases this GL context and surface as current on the current thread.
  41   virtual void ReleaseCurrent(GLSurface* surface) = 0;
  42
  43   // Returns true if this context and surface is current. Pass a null surface
  44   // if the current surface is not important.
  45   virtual bool IsCurrent(GLSurface* surface) = 0;
  46
  47   // Get the underlying platform specific GL context "handle".
  48   virtual void* GetHandle() = 0;
  49
  50   // Gets the GLStateRestore for the context.
  51   virtual GLStateRestorer* GetGLStateRestorer();
  52
  53   // Set swap interval. This context must be current.
  54   virtual void SetSwapInterval(int interval) = 0;
  55
  56   // Returns space separated list of extensions. The context must be current.
  57   virtual std::string GetExtensions();
  58
  59   // Returns in bytes the total amount of GPU memory for the GPU which this
  60   // context is currently rendering on. Returns false if no extension exists
  61   // to get the exact amount of GPU memory.
  62   virtual bool GetTotalGpuMemory(size_t* bytes);
  63
  64   // Indicate that it is safe to force this context to switch GPUs, since
  65   // transitioning can cause corruption and hangs (OS X only).
  66   virtual void SetSafeToForceGpuSwitch();
  67
  68   // Returns whether the current context supports the named extension. The
  69   // context must be current.
  70   bool HasExtension(const char* name);
  71
  72   GLShareGroup* share_group();
  73
  74   // Create a GL context that is compatible with the given surface.
  75   // |share_group|, if non-NULL, is a group of contexts which the
  76   // internally created OpenGL context shares textures and other resources.
  77   static scoped_refptr<GLContext> CreateGLContext(
  78       GLShareGroup* share_group,
  79       GLSurface* compatible_surface,
  80       GpuPreference gpu_preference);
  81
  82   static bool LosesAllContextsOnContextLost();
  83
  84   static GLContext* GetCurrent();
  85
  86   virtual bool WasAllocatedUsingRobustnessExtension();
  87
  88   // Use this context for virtualization.
  89   void SetupForVirtualization();
  90
  91   // Make this context current when used for context virtualization.
  92   bool MakeVirtuallyCurrent(GLContext* virtual_context, GLSurface* surface);
  93
  94   // Notify this context that |virtual_context|, that was using us, is
  95   // being destroyed.
  96   void OnDestroyVirtualContext(GLContext* virtual_context);
  97
  98  protected:
  99   virtual ~GLContext();
 100
 101   // Sets the GL api to the real hardware API (vs the VirtualAPI)
 102   static void SetRealGLApi();
 103   static void SetCurrent(GLContext* context, GLSurface* surface);
 104
 105   // Initialize function pointers to extension functions in the GL
 106   // implementation. Should be called immediately after this context is made
 107   // current.
 108   bool InitializeExtensionBindings();
 109
 110  private:
 111   friend class base::RefCounted<GLContext>;
 112
 113   scoped_refptr<GLShareGroup> share_group_;
 114   scoped_ptr<VirtualGLApi> virtual_gl_api_;
 115
 116   DISALLOW_COPY_AND_ASSIGN(GLContext);
 117 };
 118
 119 }  // namespace gfx
 120
 121 #endif  // UI_GL_GL_CONTEXT_H_