ui/gl/gl_context_osmesa.cc

   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 #include "ui/gl/gl_context_osmesa.h"
   6
   7 #include <GL/osmesa.h>
   8
   9 #include "base/logging.h"
  10 #include "ui/gfx/size.h"
  11 #include "ui/gl/gl_bindings.h"
  12 #include "ui/gl/gl_surface.h"
  13
  14 namespace gfx {
  15
  16 GLContextOSMesa::GLContextOSMesa(GLShareGroup* share_group)
  17     : GLContextReal(share_group),
  18       context_(NULL) {
  19 }
  20
  21 bool GLContextOSMesa::Initialize(GLSurface* compatible_surface,
  22                                  GpuPreference gpu_preference) {
  23   DCHECK(!context_);
  24
  25   OSMesaContext share_handle = static_cast<OSMesaContext>(
  26       share_group() ? share_group()->GetHandle() : NULL);
  27
  28   GLuint format = compatible_surface->GetFormat();
  29   DCHECK_NE(format, (unsigned)0);
  30   context_ = OSMesaCreateContextExt(format,
  31                                     0,  // depth bits
  32                                     0,  // stencil bits
  33                                     0,  // accum bits
  34                                     share_handle);
  35   if (!context_) {
  36     LOG(ERROR) << "OSMesaCreateContextExt failed.";
  37     return false;
  38   }
  39
  40   return true;
  41 }
  42
  43 void GLContextOSMesa::Destroy() {
  44   if (context_) {
  45     OSMesaDestroyContext(static_cast<OSMesaContext>(context_));
  46     context_ = NULL;
  47   }
  48 }
  49
  50 bool GLContextOSMesa::MakeCurrent(GLSurface* surface) {
  51   DCHECK(context_);
  52
  53   gfx::Size size = surface->GetSize();
  54
  55   ScopedReleaseCurrent release_current;
  56   if (!OSMesaMakeCurrent(context_,
  57                          surface->GetHandle(),
  58                          GL_UNSIGNED_BYTE,
  59                          size.width(),
  60                          size.height())) {
  61     LOG(ERROR) << "OSMesaMakeCurrent failed.";
  62     Destroy();
  63     return false;
  64   }
  65
  66   // Set this as soon as the context is current, since we might call into GL.
  67   SetRealGLApi();
  68
  69   // Row 0 is at the top.
  70   OSMesaPixelStore(OSMESA_Y_UP, 0);
  71
  72   SetCurrent(surface);
  73   if (!InitializeDynamicBindings()) {
  74     return false;
  75   }
  76
  77   if (!surface->OnMakeCurrent(this)) {
  78     LOG(ERROR) << "Could not make current.";
  79     return false;
  80   }
  81
  82   release_current.Cancel();
  83   return true;
  84 }
  85
  86 void GLContextOSMesa::ReleaseCurrent(GLSurface* surface) {
  87   if (!IsCurrent(surface))
  88     return;
  89
  90   SetCurrent(NULL);
  91   // TODO: Calling with NULL here does not work to release the context.
  92   OSMesaMakeCurrent(NULL, NULL, GL_UNSIGNED_BYTE, 0, 0);
  93 }
  94
  95 bool GLContextOSMesa::IsCurrent(GLSurface* surface) {
  96   DCHECK(context_);
  97
  98   bool native_context_is_current =
  99       context_ == OSMesaGetCurrentContext();
 100
 101   // If our context is current then our notion of which GLContext is
 102   // current must be correct. On the other hand, third-party code
 103   // using OpenGL might change the current context.
 104   DCHECK(!native_context_is_current || (GetRealCurrent() == this));
 105
 106   if (!native_context_is_current)
 107     return false;
 108
 109   if (surface) {
 110     GLint width;
 111     GLint height;
 112     GLint format;
 113     void* buffer = NULL;
 114     OSMesaGetColorBuffer(context_, &width, &height, &format, &buffer);
 115     if (buffer != surface->GetHandle())
 116       return false;
 117   }
 118
 119   return true;
 120 }
 121
 122 void* GLContextOSMesa::GetHandle() {
 123   return context_;
 124 }
 125
 126 void GLContextOSMesa::SetSwapInterval(int interval) {
 127   DCHECK(IsCurrent(NULL));
 128 }
 129
 130 GLContextOSMesa::~GLContextOSMesa() {
 131   Destroy();
 132 }
 133
 134 }  // namespace gfx