backend-drm: Rewrite zpos-sorting list insertion

It's possible to write this with a few less twisty special cases. Tested
manually with a randomly-distributed input tree as well as manually
trying to hit special cases around first/last entries.

Signed-off-by: Daniel Stone <daniels@collabora.com>
This commit is contained in:
Daniel Stone 2021-12-07 15:52:58 +00:00
parent 2833c28ff1
commit 7ca7c14553

View file

@ -67,7 +67,7 @@ static void
drm_output_add_zpos_plane(struct drm_plane *plane, struct wl_list *planes)
{
struct drm_backend *b = plane->backend;
struct drm_plane_zpos *h_plane;
struct drm_plane_zpos *tmp;
struct drm_plane_zpos *plane_zpos;
plane_zpos = zalloc(sizeof(*plane_zpos));
@ -79,30 +79,14 @@ drm_output_add_zpos_plane(struct drm_plane *plane, struct wl_list *planes)
drm_debug(b, "\t\t\t\t[plane] plane %d added to candidate list\n",
plane->plane_id);
if (wl_list_empty(planes)) {
wl_list_insert(planes, &plane_zpos->link);
return;
wl_list_for_each(tmp, planes, link) {
if (tmp->plane->zpos_max > plane_zpos->plane->zpos_max) {
wl_list_insert(tmp->link.prev, &plane_zpos->link);
break;
}
}
h_plane = wl_container_of(planes->next, h_plane, link);
if (h_plane->plane->zpos_max >= plane->zpos_max) {
if (plane_zpos->link.next == NULL)
wl_list_insert(planes->prev, &plane_zpos->link);
} else {
struct drm_plane_zpos *p_zpos = NULL;
if (wl_list_length(planes) == 1) {
wl_list_insert(planes->prev, &plane_zpos->link);
return;
}
wl_list_for_each(p_zpos, planes, link) {
if (p_zpos->plane->zpos_max >
plane_zpos->plane->zpos_max)
break;
}
wl_list_insert(p_zpos->link.prev, &plane_zpos->link);
}
}
static void