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 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/synchronization/cancellation_flag.h"
  15 #include "ui/gl/gl_share_group.h"
  16 #include "ui/gl/gl_state_restorer.h"
  17 #include "ui/gl/gpu_preference.h"
  18
  19 namespace gfx {
  20
  21 class GLSurface;
  22 class VirtualGLApi;
  23 struct GLVersionInfo;
  24
  25 // Encapsulates an OpenGL context, hiding platform specific management.
  26 class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
  27  public:
  28   explicit GLContext(GLShareGroup* share_group);
  29
  30   // Initializes the GL context to be compatible with the given surface. The GL
  31   // context can be made with other surface's of the same type. The compatible
  32   // surface is only needed for certain platforms like WGL, OSMesa and GLX. It
  33   // should be specific for all platforms though.
  34   virtual bool Initialize(
  35       GLSurface* compatible_surface, GpuPreference gpu_preference) = 0;
  36
  37   // Destroys the GL context.
  38   virtual void Destroy() = 0;
  39
  40   // Makes the GL context and a surface current on the current thread.
  41   virtual bool MakeCurrent(GLSurface* surface) = 0;
  42
  43   // Releases this GL context and surface as current on the current thread.
  44   virtual void ReleaseCurrent(GLSurface* surface) = 0;
  45
  46   // Returns true if this context and surface is current. Pass a null surface
  47   // if the current surface is not important.
  48   virtual bool IsCurrent(GLSurface* surface) = 0;
  49
  50   // Get the underlying platform specific GL context "handle".
  51   virtual void* GetHandle() = 0;
  52
  53   // Gets the GLStateRestorer for the context.
  54   GLStateRestorer* GetGLStateRestorer();
  55
  56   // Sets the GLStateRestorer for the context (takes ownership).
  57   void SetGLStateRestorer(GLStateRestorer* state_restorer);
  58
  59   // Set swap interval. This context must be current.
  60   void SetSwapInterval(int interval);
  61
  62   // Forces the swap interval to zero (no vsync) regardless of any future values
  63   // passed to SetSwapInterval.
  64   void ForceSwapIntervalZero(bool force);
  65
  66   // Returns space separated list of extensions. The context must be current.
  67   virtual std::string GetExtensions();
  68
  69   // Returns in bytes the total amount of GPU memory for the GPU which this
  70   // context is currently rendering on. Returns false if no extension exists
  71   // to get the exact amount of GPU memory.
  72   virtual bool GetTotalGpuMemory(size_t* bytes);
  73
  74   // Indicate that it is safe to force this context to switch GPUs, since
  75   // transitioning can cause corruption and hangs (OS X only).
  76   virtual void SetSafeToForceGpuSwitch();
  77
  78   // Attempt to force the context to move to the GPU of its sharegroup. Return
  79   // false only in the event of an unexpected error on the context.
  80   virtual bool ForceGpuSwitchIfNeeded();
  81
  82   // Indicate that the real context switches should unbind the FBO first
  83   // (For an Android work-around only).
  84   virtual void SetUnbindFboOnMakeCurrent();
  85
  86   // Returns whether the current context supports the named extension. The
  87   // context must be current.
  88   bool HasExtension(const char* name);
  89
  90   // Returns version info of the underlying GL context. The context must be
  91   // current.
  92   const GLVersionInfo* GetVersionInfo();
  93
  94   GLShareGroup* share_group();
  95
  96   // Create a GL context that is compatible with the given surface.
  97   // |share_group|, if non-NULL, is a group of contexts which the
  98   // internally created OpenGL context shares textures and other resources.
  99   static scoped_refptr<GLContext> CreateGLContext(
 100       GLShareGroup* share_group,
 101       GLSurface* compatible_surface,
 102       GpuPreference gpu_preference);
 103
 104   static bool LosesAllContextsOnContextLost();
 105
 106   // Returns the last GLContext made current, virtual or real.
 107   static GLContext* GetCurrent();
 108
 109   virtual bool WasAllocatedUsingRobustnessExtension();
 110
 111   // Use this context for virtualization.
 112   void SetupForVirtualization();
 113
 114   // Make this context current when used for context virtualization.
 115   bool MakeVirtuallyCurrent(GLContext* virtual_context, GLSurface* surface);
 116
 117   // Notify this context that |virtual_context|, that was using us, is
 118   // being released or destroyed.
 119   void OnReleaseVirtuallyCurrent(GLContext* virtual_context);
 120
 121   // Returns the GL version string. The context must be current.
 122   virtual std::string GetGLVersion();
 123
 124   // Returns the GL renderer string. The context must be current.
 125   virtual std::string GetGLRenderer();
 126
 127  protected:
 128   virtual ~GLContext();
 129
 130   // Will release the current context when going out of scope, unless canceled.
 131   class ScopedReleaseCurrent {
 132    public:
 133     ScopedReleaseCurrent();
 134     ~ScopedReleaseCurrent();
 135
 136     void Cancel();
 137
 138    private:
 139     bool canceled_;
 140   };
 141
 142   // Sets the GL api to the real hardware API (vs the VirtualAPI)
 143   static void SetRealGLApi();
 144   virtual void SetCurrent(GLSurface* surface);
 145
 146   // Initialize function pointers to functions where the bound version depends
 147   // on GL version or supported extensions. Should be called immediately after
 148   // this context is made current.
 149   bool InitializeDynamicBindings();
 150
 151   // Returns the last real (non-virtual) GLContext made current.
 152   static GLContext* GetRealCurrent();
 153
 154   virtual void OnSetSwapInterval(int interval) = 0;
 155
 156  private:
 157   friend class base::RefCounted<GLContext>;
 158
 159   // For GetRealCurrent.
 160   friend class VirtualGLApi;
 161
 162   scoped_refptr<GLShareGroup> share_group_;
 163   scoped_ptr<VirtualGLApi> virtual_gl_api_;
 164   scoped_ptr<GLStateRestorer> state_restorer_;
 165   scoped_ptr<GLVersionInfo> version_info_;
 166
 167   int swap_interval_;
 168   bool force_swap_interval_zero_;
 169
 170   DISALLOW_COPY_AND_ASSIGN(GLContext);
 171 };
 172
 173 class GL_EXPORT GLContextReal : public GLContext {
 174  public:
 175   explicit GLContextReal(GLShareGroup* share_group);
 176
 177  protected:
 178   ~GLContextReal() override;
 179
 180   void SetCurrent(GLSurface* surface) override;
 181
 182  private:
 183   DISALLOW_COPY_AND_ASSIGN(GLContextReal);
 184 };
 185
 186 }  // namespace gfx
 187
 188 #endif  // UI_GL_GL_CONTEXT_H_