backend: Provide a default create_context()

Since we use Cogl for the context creation we can now provide a default
context creation that should just work, plus a couple of hooks to allow
plugging into the creation sequence for platforms supported by Cogl that
require special handling — like foreign displays or alpha-enabled swap
chains.

The various backends have now two choices: either replace the
create_context() in its entirety, or plug themselves into the default
context creation.
This commit is contained in:
Emmanuele Bassi 2011-11-04 15:50:47 +00:00
parent 5b1b936491
commit a918ac92cb
2 changed files with 117 additions and 3 deletions

View File

@ -68,6 +68,12 @@ struct _ClutterBackendClass
ClutterFeatureFlags (* get_features) (ClutterBackend *backend);
void (* redraw) (ClutterBackend *backend,
ClutterStage *stage);
CoglRenderer * (* get_renderer) (ClutterBackend *backend,
GError **error);
CoglDisplay * (* get_display) (ClutterBackend *backend,
CoglRenderer *renderer,
CoglSwapChain *swap_chain,
GError **error);
gboolean (* create_context) (ClutterBackend *backend,
GError **error);
void (* ensure_context) (ClutterBackend *backend,

View File

@ -226,6 +226,115 @@ clutter_backend_real_font_changed (ClutterBackend *backend)
CLUTTER_NOTE (BACKEND, "Units per em: %.2f", priv->units_per_em);
}
static gboolean
clutter_backend_real_create_context (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
CoglSwapChain *swap_chain;
GError *internal_error;
if (backend->cogl_context != NULL)
return TRUE;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
swap_chain = NULL;
internal_error = NULL;
CLUTTER_NOTE (BACKEND, "Creating Cogl renderer");
if (klass->get_renderer != NULL)
backend->cogl_renderer = klass->get_renderer (backend, &internal_error);
else
backend->cogl_renderer = cogl_renderer_new ();
if (backend->cogl_renderer == NULL)
goto error;
CLUTTER_NOTE (BACKEND, "Connecting the renderer");
if (!cogl_renderer_connect (backend->cogl_renderer, &internal_error))
goto error;
CLUTTER_NOTE (BACKEND, "Creating Cogl swap chain");
swap_chain = cogl_swap_chain_new ();
CLUTTER_NOTE (BACKEND, "Creating Cogl display");
if (klass->get_display != NULL)
{
backend->cogl_display = klass->get_display (backend,
backend->cogl_renderer,
swap_chain,
&internal_error);
}
else
{
CoglOnscreenTemplate *tmpl;
gboolean res;
tmpl = cogl_onscreen_template_new (swap_chain);
/* XXX: I have some doubts that this is a good design.
*
* Conceptually should we be able to check an onscreen_template
* without more details about the CoglDisplay configuration?
*/
res = cogl_renderer_check_onscreen_template (backend->cogl_renderer,
tmpl,
&internal_error);
if (!res)
goto error;
backend->cogl_display = cogl_display_new (backend->cogl_renderer, tmpl);
/* the display owns the template */
cogl_object_unref (tmpl);
}
if (backend->cogl_display == NULL)
goto error;
CLUTTER_NOTE (BACKEND, "Setting up the display");
if (!cogl_display_setup (backend->cogl_display, &internal_error))
goto error;
CLUTTER_NOTE (BACKEND, "Creating the Cogl context");
backend->cogl_context = cogl_context_new (backend->cogl_display, &internal_error);
if (backend->cogl_context == NULL)
goto error;
/* the display owns the renderer and the swap chain */
cogl_object_unref (backend->cogl_renderer);
cogl_object_unref (swap_chain);
return TRUE;
error:
if (backend->cogl_display != NULL)
{
cogl_object_unref (backend->cogl_display);
backend->cogl_display = NULL;
}
if (backend->cogl_renderer != NULL)
{
cogl_object_unref (backend->cogl_renderer);
backend->cogl_renderer = NULL;
}
if (swap_chain != NULL)
cogl_object_unref (swap_chain);
if (internal_error != NULL)
g_propagate_error (error, internal_error);
else
g_set_error_literal (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
_("Unable to initialize the Clutter backend"));
return FALSE;
}
static void
clutter_backend_real_ensure_context (ClutterBackend *backend,
ClutterStage *stage)
@ -429,6 +538,7 @@ clutter_backend_class_init (ClutterBackendClass *klass)
klass->init_events = clutter_backend_real_init_events;
klass->translate_event = clutter_backend_real_translate_event;
klass->create_context = clutter_backend_real_create_context;
klass->ensure_context = clutter_backend_real_ensure_context;
klass->redraw = clutter_backend_real_redraw;
}
@ -546,10 +656,8 @@ _clutter_backend_create_context (ClutterBackend *backend,
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->create_context)
return klass->create_context (backend, error);
return TRUE;
return klass->create_context (backend, error);
}
void