effects: Fix stacking of offscreen-based effects

Stacking multiple effects sub-classing ClutterOffscreenEffect requires
a small fix in the code that computes the screen coordinates of the
actor to position the FBO correctly with regards to the stage.
This commit is contained in:
Emmanuele Bassi 2010-06-03 14:08:59 +01:00
parent 8ef4d9fe21
commit aef2f805a6
2 changed files with 13 additions and 0 deletions

View File

@ -204,6 +204,7 @@ get_screen_offsets (ClutterActor *actor,
{
ClutterVertex verts[4];
gfloat x_min = G_MAXFLOAT, y_min = G_MAXFLOAT;
gfloat v[4] = { 0, };
gint i;
/* Get the actors allocation transformed into screen coordinates.
@ -231,6 +232,17 @@ get_screen_offsets (ClutterActor *actor,
*y_offset = ROUND (y_min);
#undef ROUND
/* since we're setting up a viewport with a negative offset to paint
* in an FBO with the same modelview and projection matrices as the
* stage, we need to offset the computed absolute allocation vertices
* with the current viewport's X and Y offsets. this works even with
* the default case where the viewport is set up by Clutter to be
* (0, 0, stage_width, stage_height)
*/
cogl_get_viewport (v);
*x_offset -= v[0];
*y_offset -= v[1];
}
static gboolean

View File

@ -40,6 +40,7 @@ test_rotate_main (int argc, char *argv[])
clutter_actor_set_position (hand, 240, 140);
clutter_actor_show (hand);
clutter_actor_add_effect_with_name (hand, "desaturate", clutter_desaturate_effect_new (0.75));
clutter_actor_add_effect_with_name (hand, "blur", clutter_blur_effect_new ());
clutter_actor_animate_with_timeline (hand, CLUTTER_LINEAR, timeline,
"@effects.desaturate.factor", 1.0,
NULL);