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/geometry/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_(nullptr),
  19       is_released_(false) {
  20 }
  21
  22 bool GLContextOSMesa::Initialize(GLSurface* compatible_surface,
  23                                  GpuPreference gpu_preference) {
  24   DCHECK(!context_);
  25
  26   OSMesaContext share_handle = static_cast<OSMesaContext>(
  27       share_group() ? share_group()->GetHandle() : nullptr);
  28
  29   GLuint format = compatible_surface->GetFormat();
  30   DCHECK_NE(format, (unsigned)0);
  31   context_ = OSMesaCreateContextExt(format,
  32                                     0,  // depth bits
  33                                     0,  // stencil bits
  34                                     0,  // accum bits
  35                                     share_handle);
  36   if (!context_) {
  37     LOG(ERROR) << "OSMesaCreateContextExt failed.";
  38     return false;
  39   }
  40
  41   return true;
  42 }
  43
  44 void GLContextOSMesa::Destroy() {
  45   if (context_) {
  46     OSMesaDestroyContext(static_cast<OSMesaContext>(context_));
  47     context_ = nullptr;
  48   }
  49 }
  50
  51 bool GLContextOSMesa::MakeCurrent(GLSurface* surface) {
  52   DCHECK(context_);
  53
  54   gfx::Size size = surface->GetSize();
  55
  56   ScopedReleaseCurrent release_current;
  57   if (!OSMesaMakeCurrent(context_,
  58                          surface->GetHandle(),
  59                          GL_UNSIGNED_BYTE,
  60                          size.width(),
  61                          size.height())) {
  62     LOG(ERROR) << "OSMesaMakeCurrent failed.";
  63     Destroy();
  64     return false;
  65   }
  66   // Track that we're no longer in a released state to workaround a mesa issue.
  67   is_released_ = false;
  68
  69   // Set this as soon as the context is current, since we might call into GL.
  70   SetRealGLApi();
  71
  72   // Row 0 is at the top.
  73   OSMesaPixelStore(OSMESA_Y_UP, 0);
  74
  75   SetCurrent(surface);
  76   if (!InitializeDynamicBindings()) {
  77     return false;
  78   }
  79
  80   if (!surface->OnMakeCurrent(this)) {
  81     LOG(ERROR) << "Could not make current.";
  82     return false;
  83   }
  84
  85   release_current.Cancel();
  86   return true;
  87 }
  88
  89 void GLContextOSMesa::ReleaseCurrent(GLSurface* surface) {
  90   if (!IsCurrent(surface))
  91     return;
  92
  93   SetCurrent(nullptr);
  94
  95   // Calling |OSMesaMakeCurrent| with nullptr here does not work to release the
  96   // context. As a workaround, keep track of the release state, so that we can
  97   // correctly determine the state of |IsCurrent|.
  98   is_released_ = true;
  99   OSMesaMakeCurrent(nullptr, nullptr, GL_UNSIGNED_BYTE, 0, 0);
 100 }
 101
 102 bool GLContextOSMesa::IsCurrent(GLSurface* surface) {
 103   DCHECK(context_);
 104
 105   // |OSMesaGetCurrentContext| doesn't correctly return nullptr when we release,
 106   // check the tracked |is_released_|. See |ReleaseCurrent|.
 107   bool native_context_is_current = !is_released_ &&
 108       context_ == OSMesaGetCurrentContext();
 109
 110   // If our context is current then our notion of which GLContext is
 111   // current must be correct. On the other hand, third-party code
 112   // using OpenGL might change the current context.
 113   DCHECK(!native_context_is_current || (GetRealCurrent() == this));
 114
 115   if (!native_context_is_current)
 116     return false;
 117
 118   if (surface) {
 119     GLint width;
 120     GLint height;
 121     GLint format;
 122     void* buffer = nullptr;
 123     OSMesaGetColorBuffer(context_, &width, &height, &format, &buffer);
 124     if (buffer != surface->GetHandle())
 125       return false;
 126   }
 127
 128   return true;
 129 }
 130
 131 void* GLContextOSMesa::GetHandle() {
 132   return context_;
 133 }
 134
 135 void GLContextOSMesa::OnSetSwapInterval(int interval) {
 136   DCHECK(IsCurrent(nullptr));
 137 }
 138
 139 GLContextOSMesa::~GLContextOSMesa() {
 140   Destroy();
 141 }
 142
 143 }  // namespace gfx