+ my (@mods, $last_layer);
+MOD:
+ for my $mod ($set->mods) {
+ my $is_layer = $ltml_tc->check($mod);
+ $last_layer = $mod if $is_layer;
+ my $tag = $mod->tag;
+ my $old = $mods{$tag} || [];
+ for (@$old) {
+ next MOD if $_->[0]->covers($mod);
+ }
+ push @{$mods{$tag}}, [ $mod, $last_mod++, $is_layer ];
+ push @mods, $mod;
+ }
+
+ if ($last_layer) {
+ # Clips and mods don't propagate through layers. Hence if a layer is set,
+ # force their reuse.
+ @mods = $last_layer;
+ push @mods, map $_->[0],
+ sort { $a->[1] <=> $b->[1] }
+ grep !$_->[2],
+ map @$_,
+ values %mods;
+ }