GlxContext::GlxContext(GlxContext* shared) :
m_display (NULL),
m_window (0),
m_context (NULL),
m_pbuffer (0),
m_ownsWindow(false)
{
// Save the creation settings
m_settings = ContextSettings();
// Make sure that extensions are initialized if this is not the shared context
// The shared context is the context used to initialize the extensions
if (shared && shared->m_display)
ensureExtensionsInit(shared->m_display, DefaultScreen(shared->m_display));
// Create the rendering surface (window or pbuffer if supported)
createSurface(shared, 1, 1, VideoMode::getDesktopMode().bitsPerPixel);
// Create the context
createContext(shared);
}
GlxContext::GlxContext(GlxContext* shared, const ContextSettings& settings, const WindowImpl* owner, unsigned int bitsPerPixel) :
m_display (NULL),
m_window (0),
m_context (NULL),
m_pbuffer (0),
m_ownsWindow(false)
{
// Save the creation settings
m_settings = settings;
// Make sure that extensions are initialized if this is not the shared context
// The shared context is the context used to initialize the extensions
if (shared && shared->m_display)
ensureExtensionsInit(shared->m_display, DefaultScreen(shared->m_display));
// Create the rendering surface from the owner window
createSurface(static_cast< ::Window>(owner->getSystemHandle()));
// Create the context
createContext(shared);
}
void GlxContext::setVerticalSyncEnabled(bool enabled)
{
// Make sure that extensions are initialized
ensureExtensionsInit(m_display, DefaultScreen(m_display));
int result = 0;
// Prioritize the EXT variant and fall back to MESA or SGI if needed
// We use the direct pointer to the MESA entry point instead of the alias
// because glx.h declares the entry point as an external function
// which would require us to link in an additional library
if (sfglx_ext_EXT_swap_control == sfglx_LOAD_SUCCEEDED)
{
glXSwapIntervalEXT(m_display, m_pbuffer ? m_pbuffer : m_window, enabled ? 1 : 0);
}
else if (sfglx_ext_MESA_swap_control == sfglx_LOAD_SUCCEEDED)
{
result = sf_ptrc_glXSwapIntervalMESA(enabled ? 1 : 0);
}
else if (sfglx_ext_SGI_swap_control == sfglx_LOAD_SUCCEEDED)
{
result = glXSwapIntervalSGI(enabled ? 1 : 0);
}
else
{
static bool warned = false;
if (!warned)
{
err() << "Setting vertical sync not supported" << std::endl;
warned = true;
}
}
if (result != 0)
err() << "Setting vertical sync failed" << std::endl;
}
void GlxContext::createContext(GlxContext* shared, unsigned int bitsPerPixel, const ContextSettings& settings)
{
// Save the creation settings
m_settings = settings;
// Retrieve the attributes of the target window
XWindowAttributes windowAttributes;
if (XGetWindowAttributes(m_display, m_window, &windowAttributes) == 0)
{
err() << "Failed to get the window attributes" << std::endl;
return;
}
// Get its visuals
XVisualInfo tpl;
tpl.screen = DefaultScreen(m_display);
tpl.visualid = XVisualIDFromVisual(windowAttributes.visual);
int nbVisuals = 0;
XVisualInfo* visualInfo = XGetVisualInfo(m_display, VisualIDMask | VisualScreenMask, &tpl, &nbVisuals);
// Get the context to share display lists with
GLXContext toShare = shared ? shared->m_context : NULL;
// There are no GLX versions prior to 1.0
int major = 0;
int minor = 0;
if (!glXQueryVersion(m_display, &major, &minor))
err() << "Failed to query GLX version, limited to legacy context creation" << std::endl;
// Make sure that extensions are initialized if this is not the shared context
// The shared context is the context used to initialize the extensions
if (shared)
ensureExtensionsInit(m_display, DefaultScreen(m_display));
// Check if glXCreateContextAttribsARB is available (requires GLX 1.3 or greater)
bool hasCreateContextArb = (sfglx_ext_ARB_create_context == sfglx_LOAD_SUCCEEDED) && ((major > 1) || (minor >= 3));
// Check if we need to use glXCreateContextAttribsARB
bool needCreateContextArb = false;
if (m_settings.attributeFlags)
needCreateContextArb = true;
else if (m_settings.majorVersion >= 3)
needCreateContextArb = true;
// Create the OpenGL context -- first try using glXCreateContextAttribsARB if we need to
if (hasCreateContextArb && needCreateContextArb)
{
// Get a GLXFBConfig that matches the the window's visual, for glXCreateContextAttribsARB
GLXFBConfig* config = NULL;
// We don't supply attributes to match against, since
// the visual we are matching against was already
// deemed suitable in selectBestVisual()
int nbConfigs = 0;
GLXFBConfig* configs = glXChooseFBConfig(m_display, DefaultScreen(m_display), NULL, &nbConfigs);
for (int i = 0; configs && (i < nbConfigs); ++i)
{
XVisualInfo* visual = glXGetVisualFromFBConfig(m_display, configs[i]);
if (!visual)
continue;
if (visual->visualid == visualInfo->visualid)
{
config = &configs[i];
break;
}
}
if (!config)
err() << "Failed to get GLXFBConfig which corresponds to the window's visual" << std::endl;
while (config && !m_context && m_settings.majorVersion)
{
// Check if setting the profile is supported
if (sfglx_ext_ARB_create_context_profile == sfglx_LOAD_SUCCEEDED)
{
int profile = (m_settings.attributeFlags & ContextSettings::Core) ? GLX_CONTEXT_CORE_PROFILE_BIT_ARB : GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
int debug = (m_settings.attributeFlags & ContextSettings::Debug) ? GLX_CONTEXT_DEBUG_BIT_ARB : 0;
// Create the context
int attributes[] =
{
GLX_CONTEXT_MAJOR_VERSION_ARB, static_cast<int>(m_settings.majorVersion),
GLX_CONTEXT_MINOR_VERSION_ARB, static_cast<int>(m_settings.minorVersion),
GLX_CONTEXT_PROFILE_MASK_ARB, profile,
GLX_CONTEXT_FLAGS_ARB, debug,
0, 0
};
// RAII GLX error handler (we simply ignore errors here)
// On an error, glXCreateContextAttribsARB will return 0 anyway
GlxErrorHandler handler(m_display);
m_context = glXCreateContextAttribsARB(m_display, *config, toShare, true, attributes);
}
else
{
if ((m_settings.attributeFlags & ContextSettings::Core) || (m_settings.attributeFlags & ContextSettings::Debug))
err() << "Selecting a profile during context creation is not supported,"
<< "disabling comptibility and debug" << std::endl;
m_settings.attributeFlags = ContextSettings::Default;
// Create the context
int attributes[] =
{
GLX_CONTEXT_MAJOR_VERSION_ARB, static_cast<int>(m_settings.majorVersion),
GLX_CONTEXT_MINOR_VERSION_ARB, static_cast<int>(m_settings.minorVersion),
0, 0
};
// RAII GLX error handler (we simply ignore errors here)
// On an error, glXCreateContextAttribsARB will return 0 anyway
GlxErrorHandler handler(m_display);
m_context = glXCreateContextAttribsARB(m_display, *config, toShare, true, attributes);
}
if (!m_context)
{
// If we couldn't create the context, first try disabling flags,
// then lower the version number and try again -- stop at 0.0
// Invalid version numbers will be generated by this algorithm (like 3.9), but we really don't care
if (m_settings.attributeFlags != ContextSettings::Default)
{
m_settings.attributeFlags = ContextSettings::Default;
}
else if (m_settings.minorVersion > 0)
{
// If the minor version is not 0, we decrease it and try again
m_settings.minorVersion--;
m_settings.attributeFlags = settings.attributeFlags;
}
else
{
// If the minor version is 0, we decrease the major version
m_settings.majorVersion--;
m_settings.minorVersion = 9;
m_settings.attributeFlags = settings.attributeFlags;
}
}
}
if (configs)
XFree(configs);
}
// If glXCreateContextAttribsARB failed, use glXCreateContext
if (!m_context)
{
// set the context version to 2.1 (arbitrary) and disable flags
m_settings.majorVersion = 2;
m_settings.minorVersion = 1;
m_settings.attributeFlags = ContextSettings::Default;
#if defined(GLX_DEBUGGING)
GlxErrorHandler handler(m_display);
#endif
// Create the context, using the target window's visual
m_context = glXCreateContext(m_display, visualInfo, toShare, true);
#if defined(GLX_DEBUGGING)
if (glxErrorOccurred)
err() << "GLX error in GlxContext::createContext()" << std::endl;
#endif
}
if (!m_context)
{
err() << "Failed to create an OpenGL context for this window" << std::endl;
}
else
{
// Update the creation settings from the chosen format
int depth, stencil, multiSampling, samples;
glXGetConfig(m_display, visualInfo, GLX_DEPTH_SIZE, &depth);
glXGetConfig(m_display, visualInfo, GLX_STENCIL_SIZE, &stencil);
if (sfglx_ext_ARB_multisample == sfglx_LOAD_SUCCEEDED)
{
glXGetConfig(m_display, visualInfo, GLX_SAMPLE_BUFFERS_ARB, &multiSampling);
glXGetConfig(m_display, visualInfo, GLX_SAMPLES_ARB, &samples);
}
else
{
multiSampling = 0;
samples = 0;
}
m_settings.depthBits = static_cast<unsigned int>(depth);
m_settings.stencilBits = static_cast<unsigned int>(stencil);
m_settings.antialiasingLevel = multiSampling ? samples : 0;
}
// Free the visual info
XFree(visualInfo);
}
