static gboolean
check_onscreen_template (CoglRenderer *renderer,
CoglSwapChain *swap_chain,
CoglOnscreenTemplate *onscreen_template,
CoglBool enable_argb,
CoglBool enable_stereo,
GError **error)
{
GError *internal_error = NULL;
cogl_swap_chain_set_has_alpha (swap_chain, enable_argb);
cogl_onscreen_template_set_stereo_enabled (onscreen_template,
clutter_enable_stereo);
/* cogl_renderer_check_onscreen_template() is actually just a
* shorthand for creating a CoglDisplay, and calling
* cogl_display_setup() on it, then throwing the display away. If we
* could just return that display, then it would be more efficient
* not to use cogl_renderer_check_onscreen_template(). However, the
* backend API requires that we return an CoglDisplay that has not
* yet been setup, so one way or the other we'll have to discard the
* first display and make a new fresh one.
*/
if (cogl_renderer_check_onscreen_template (renderer, onscreen_template, &internal_error))
{
clutter_enable_argb = enable_argb;
clutter_enable_stereo = enable_stereo;
return TRUE;
}
else
{
if (enable_argb || enable_stereo) /* More possibilities to try */
CLUTTER_NOTE (BACKEND,
"Creation of a CoglDisplay with alpha=%s, stereo=%s failed: %s",
enable_argb ? "enabled" : "disabled",
enable_stereo ? "enabled" : "disabled",
internal_error != NULL
? internal_error->message
: "Unknown reason");
else
g_set_error_literal (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
internal_error != NULL
? internal_error->message
: "Creation of a CoglDisplay failed");
g_clear_error (&internal_error);
return FALSE;
}
}
static CoglDisplay *
clutter_backend_gdk_get_display (ClutterBackend *backend,
CoglRenderer *renderer,
CoglSwapChain *swap_chain,
GError **error)
{
ClutterBackendGdk *backend_gdk = CLUTTER_BACKEND_GDK (backend);
CoglOnscreenTemplate *onscreen_template;
GError *internal_error = NULL;
CoglDisplay *display;
gboolean has_rgba_visual;
gboolean res;
has_rgba_visual = gdk_screen_get_rgba_visual (backend_gdk->screen) == NULL;
CLUTTER_NOTE (BACKEND, "Alpha on Cogl swap chain: %s",
has_rgba_visual ? "enabled" : "disabled");
cogl_swap_chain_set_has_alpha (swap_chain, has_rgba_visual);
onscreen_template = cogl_onscreen_template_new (swap_chain);
res = cogl_renderer_check_onscreen_template (renderer,
onscreen_template,
&internal_error);
if (!res && has_rgba_visual)
{
CLUTTER_NOTE (BACKEND,
"Creation of a context with a ARGB visual failed: %s",
internal_error != NULL ? internal_error->message
: "Unknown reason");
g_clear_error (&internal_error);
/* It's possible that the current renderer doesn't support transparency
* in a swap_chain so lets see if we can fallback to not having any
* transparency...
*
* XXX: It might be nice to have a CoglRenderer feature we could
* explicitly check for ahead of time.
*/
cogl_swap_chain_set_has_alpha (swap_chain, FALSE);
res = cogl_renderer_check_onscreen_template (renderer,
onscreen_template,
&internal_error);
}
if (!res)
{
g_set_error_literal (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
internal_error->message);
g_error_free (internal_error);
cogl_object_unref (onscreen_template);
return NULL;
}
display = cogl_display_new (renderer, onscreen_template);
cogl_object_unref (onscreen_template);
return display;
}
