Index: trunk/src/obj_subc.c
===================================================================
--- trunk/src/obj_subc.c	(revision 13011)
+++ trunk/src/obj_subc.c	(revision 13012)
@@ -179,7 +179,23 @@
 	return 0;
 }
 
+int pcb_subc_get_side(pcb_subc_t *sc, int *on_bottom)
+{
+	if ((pcb_subc_cache_update(sc) != 0) || (sc->aux_layer == NULL))
+		return -1;
+	if (!sc->aux_layer->is_bound)
+		return -1;
 
+	if (sc->aux_layer->meta.bound.type & PCB_LYT_TOP)
+		*on_bottom = 0;
+	else if (sc->aux_layer->meta.bound.type & PCB_LYT_BOTTOM)
+		*on_bottom = 1;
+	else
+		return -1;
+
+	return 0;
+}
+
 static void pcb_subc_cache_invalidate(pcb_subc_t *sc)
 {
 	sc->aux_cache[0] = NULL;
Index: trunk/src/obj_subc.h
===================================================================
--- trunk/src/obj_subc.h	(revision 13011)
+++ trunk/src/obj_subc.h	(revision 13012)
@@ -80,6 +80,7 @@
 /* calculate geometrical properties using the aux layer; return 0 on success */
 int pcb_subc_get_origin(pcb_subc_t *sc, pcb_coord_t *x, pcb_coord_t *y);
 int pcb_subc_get_rotation(pcb_subc_t *sc, double *rot);
+int pcb_subc_get_side(pcb_subc_t *sc, int *on_bottom);
 
 /* Search for the named subc; name is relative path in hierarchy. Returns
    NULL if not found */