static gboolean
clutter_backend_glx_create_context (ClutterBackend *backend,
gboolean is_offscreen,
GError **error)
{
ClutterBackendGLX *backend_glx = CLUTTER_BACKEND_GLX (backend);
ClutterBackendX11 *backend_x11 = CLUTTER_BACKEND_X11 (backend);
if (backend_glx->gl_context == None)
{
XVisualInfo *xvisinfo;
xvisinfo =
clutter_backend_x11_get_visual_info (backend_x11, is_offscreen);
CLUTTER_NOTE (GL, "Creating GL Context (display: %p, %s)",
backend_x11->xdpy,
is_offscreen ? "offscreen" : "onscreen");
backend_glx->gl_context = glXCreateContext (backend_x11->xdpy,
xvisinfo,
0,
is_offscreen ? False : True);
XFree (xvisinfo);
if (backend_glx->gl_context == None)
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
"Unable to create suitable %s GL context",
is_offscreen ? "offscreen" : "onscreen");
return FALSE;
}
if (!is_offscreen)
{
gboolean is_direct;
is_direct = glXIsDirect (backend_x11->xdpy,
backend_glx->gl_context);
CLUTTER_NOTE (GL, "Setting %s context",
is_direct ? "direct" : "indirect");
_cogl_set_indirect_context (!is_direct);
}
}
return TRUE;
}
static gboolean
clutter_backend_glx_create_context (ClutterBackend *backend,
GError **error)
{
ClutterBackendGLX *backend_glx = CLUTTER_BACKEND_GLX (backend);
ClutterBackendX11 *backend_x11 = CLUTTER_BACKEND_X11 (backend);
GLXFBConfig config;
gboolean is_direct;
Window root_xwin;
XSetWindowAttributes attrs;
XVisualInfo *xvisinfo;
Display *xdisplay;
int major;
int minor;
GLXDrawable dummy_drawable;
if (backend_glx->gl_context != None)
return TRUE;
xdisplay = clutter_x11_get_default_display ();
root_xwin = clutter_x11_get_root_window ();
if (!_clutter_backend_glx_get_fbconfig (backend_glx, &config))
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
"Unable to find suitable fbconfig for the GLX context");
return FALSE;
}
CLUTTER_NOTE (BACKEND, "Creating GLX Context (display: %p)", xdisplay);
backend_glx->gl_context = glXCreateNewContext (xdisplay,
config,
GLX_RGBA_TYPE,
NULL,
True);
if (backend_glx->gl_context == None)
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
"Unable to create suitable GL context");
return FALSE;
}
is_direct = glXIsDirect (xdisplay, backend_glx->gl_context);
CLUTTER_NOTE (GL, "Setting %s context",
is_direct ? "direct"
: "indirect");
_cogl_set_indirect_context (!is_direct);
/* COGL assumes that there is always a GL context selected; in order
* to make sure that a GLX context exists and is made current, we use
* a dummy, offscreen override-redirect window to which we can always
* fall back if no stage is available
*
* XXX - we need to do this dance because GLX does not allow creating
* a context and querying it for basic information (even the function
* pointers) unless it's made current to a real Drawable. it should be
* possible to avoid this in future releases of Mesa and X11, but right
* now this is the best solution available.
*/
xvisinfo = glXGetVisualFromFBConfig (xdisplay, config);
if (xvisinfo == None)
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
"Unable to retrieve the X11 visual");
return FALSE;
}
clutter_x11_trap_x_errors ();
attrs.override_redirect = True;
attrs.colormap = XCreateColormap (xdisplay,
root_xwin,
xvisinfo->visual,
AllocNone);
attrs.border_pixel = 0;
backend_glx->dummy_xwin = XCreateWindow (xdisplay, root_xwin,
-100, -100, 1, 1,
0,
xvisinfo->depth,
CopyFromParent,
xvisinfo->visual,
CWOverrideRedirect | CWColormap | CWBorderPixel,
&attrs);
/* Try and create a GLXWindow to use with extensions dependent on
* GLX versions >= 1.3 that don't accept regular X Windows as GLX
* drawables. */
if (glXQueryVersion (backend_x11->xdpy, &major, &minor) &&
major == 1 && minor >= 3)
{
backend_glx->dummy_glxwin = glXCreateWindow (backend_x11->xdpy,
config,
backend_glx->dummy_xwin,
NULL);
}
if (backend_glx->dummy_glxwin)
dummy_drawable = backend_glx->dummy_glxwin;
else
dummy_drawable = backend_glx->dummy_xwin;
CLUTTER_NOTE (BACKEND, "Selecting dummy 0x%x for the GLX context",
(unsigned int) dummy_drawable);
glXMakeContextCurrent (xdisplay,
dummy_drawable,
dummy_drawable,
backend_glx->gl_context);
XFree (xvisinfo);
if (clutter_x11_untrap_x_errors ())
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
"Unable to select the newly created GLX context");
return FALSE;
}
return TRUE;
}
