Home | History | Annotate | Download | only in gl 
      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/gl_state_restorer.h"
     15 #include "ui/gl/gpu_preference.h"
     16 
     17 namespace gfx {
     18 
     19 class GLSurface;
     20 class VirtualGLApi;
     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 GLStateRestorer for the context.
     51   GLStateRestorer* GetGLStateRestorer();
     52 
     53   // Sets the GLStateRestorer for the context (takes ownership).
     54   void SetGLStateRestorer(GLStateRestorer* state_restorer);
     55 
     56   // Set swap interval. This context must be current.
     57   virtual void SetSwapInterval(int interval) = 0;
     58 
     59   // Returns space separated list of extensions. The context must be current.
     60   virtual std::string GetExtensions();
     61 
     62   // Returns in bytes the total amount of GPU memory for the GPU which this
     63   // context is currently rendering on. Returns false if no extension exists
     64   // to get the exact amount of GPU memory.
     65   virtual bool GetTotalGpuMemory(size_t* bytes);
     66 
     67   // Indicate that it is safe to force this context to switch GPUs, since
     68   // transitioning can cause corruption and hangs (OS X only).
     69   virtual void SetSafeToForceGpuSwitch();
     70 
     71   // Indicate that the real context switches should unbind the FBO first
     72   // (For an Android work-around only).
     73   virtual void SetUnbindFboOnMakeCurrent();
     74 
     75   // Returns whether the current context supports the named extension. The
     76   // context must be current.
     77   bool HasExtension(const char* name);
     78 
     79   GLShareGroup* share_group();
     80 
     81   // Create a GL context that is compatible with the given surface.
     82   // |share_group|, if non-NULL, is a group of contexts which the
     83   // internally created OpenGL context shares textures and other resources.
     84   static scoped_refptr<GLContext> CreateGLContext(
     85       GLShareGroup* share_group,
     86       GLSurface* compatible_surface,
     87       GpuPreference gpu_preference);
     88 
     89   static bool LosesAllContextsOnContextLost();
     90 
     91   // Returns the last GLContext made current, virtual or real.
     92   static GLContext* GetCurrent();
     93 
     94   virtual bool WasAllocatedUsingRobustnessExtension();
     95 
     96   // Use this context for virtualization.
     97   void SetupForVirtualization();
     98 
     99   // Make this context current when used for context virtualization.
    100   bool MakeVirtuallyCurrent(GLContext* virtual_context, GLSurface* surface);
    101 
    102   // Notify this context that |virtual_context|, that was using us, is
    103   // being released or destroyed.
    104   void OnReleaseVirtuallyCurrent(GLContext* virtual_context);
    105 
    106  protected:
    107   virtual ~GLContext();
    108 
    109   // Sets the GL api to the real hardware API (vs the VirtualAPI)
    110   static void SetRealGLApi();
    111   virtual void SetCurrent(GLSurface* surface);
    112 
    113   // Initialize function pointers to extension functions in the GL
    114   // implementation. Should be called immediately after this context is made
    115   // current.
    116   bool InitializeExtensionBindings();
    117 
    118   // Returns the last real (non-virtual) GLContext made current.
    119   static GLContext* GetRealCurrent();
    120 
    121  private:
    122   friend class base::RefCounted<GLContext>;
    123 
    124   // For GetRealCurrent.
    125   friend class VirtualGLApi;
    126 
    127   scoped_refptr<GLShareGroup> share_group_;
    128   scoped_ptr<VirtualGLApi> virtual_gl_api_;
    129   scoped_ptr<GLStateRestorer> state_restorer_;
    130 
    131   DISALLOW_COPY_AND_ASSIGN(GLContext);
    132 };
    133 
    134 class GL_EXPORT GLContextReal : public GLContext {
    135  public:
    136   explicit GLContextReal(GLShareGroup* share_group);
    137 
    138  protected:
    139   virtual ~GLContextReal();
    140 
    141   virtual void SetCurrent(GLSurface* surface) OVERRIDE;
    142 
    143  private:
    144   DISALLOW_COPY_AND_ASSIGN(GLContextReal);
    145 };
    146 
    147 }  // namespace gfx
    148 
    149 #endif  // UI_GL_GL_CONTEXT_H_
    150