actor: add oob-transform opt to catch out-of-band transforms

Out-of-band transforms are considered to be all actor transforms done
directly with the Cogl API instead of via ClutterActor::apply_transform.

By running with CLUTTER_DEBUG=oob-transform then Clutter will explicitly
try to detect when un-expected transforms have been applied to the
modelview matrix stack.

Out-of-band transforms can lead to awkward bugs in Clutter applications
because Clutter itself doesn't know about them and this can disrupt
Clutter's input handling and calculations of actor paint-volumes
which can lead to visual artifacts.

Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
This commit is contained in:
Robert Bragg 2011-09-19 12:36:52 +01:00
parent f315e760de
commit 662d12aeff
3 changed files with 27 additions and 2 deletions

View File

@ -2864,6 +2864,29 @@ clutter_actor_paint (ClutterActor *self)
cogl_get_modelview_matrix (&matrix);
_clutter_actor_apply_modelview_transform (self, &matrix);
cogl_set_modelview_matrix (&matrix);
/* Catch when out-of-band transforms have been made by actors not as part
* of an apply_transform vfunc... */
if (G_UNLIKELY (clutter_debug_flags & CLUTTER_DEBUG_OOB_TRANSFORMS))
{
CoglMatrix expected_matrix;
_clutter_actor_get_relative_transformation_matrix (self, NULL,
&expected_matrix);
if (!cogl_matrix_equal (&matrix, &expected_matrix))
{
ClutterActor *parent = self;
GString *parents = g_string_new ("");
while ((parent = clutter_actor_get_parent (parent)))
g_string_append_printf (parents, "->%s", G_OBJECT_TYPE_NAME (parent));
g_warning ("Unexpected transform found when painting actor "
"\"%s\". This will be caused by one of the actor's "
"ancestors (%s) using the Cogl API directly to transform "
"children instead of using ::apply_transform().",
_clutter_actor_get_debug_name (self),
parents->str);
g_string_free (parents, TRUE);
}
}
}
if (priv->has_clip)

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@ -26,7 +26,8 @@ typedef enum {
CLUTTER_DEBUG_LAYOUT = 1 << 15,
CLUTTER_DEBUG_PICK = 1 << 16,
CLUTTER_DEBUG_EVENTLOOP = 1 << 17,
CLUTTER_DEBUG_CLIPPING = 1 << 18
CLUTTER_DEBUG_CLIPPING = 1 << 18,
CLUTTER_DEBUG_OOB_TRANSFORMS = 1 << 19
} ClutterDebugFlag;
typedef enum {

View File

@ -167,7 +167,8 @@ static const GDebugKey clutter_debug_keys[] = {
{ "multistage", CLUTTER_DEBUG_MULTISTAGE },
{ "animation", CLUTTER_DEBUG_ANIMATION },
{ "layout", CLUTTER_DEBUG_LAYOUT },
{ "clipping", CLUTTER_DEBUG_CLIPPING }
{ "clipping", CLUTTER_DEBUG_CLIPPING },
{ "oob-transforms", CLUTTER_DEBUG_OOB_TRANSFORMS }
};
#endif /* CLUTTER_ENABLE_DEBUG */