Index: trunk/src/obj_common.h
===================================================================
--- trunk/src/obj_common.h	(revision 14728)
+++ trunk/src/obj_common.h	(revision 14729)
@@ -29,6 +29,7 @@
 #ifndef PCB_OBJ_COMMON_H
 #define PCB_OBJ_COMMON_H
 
+#include <math.h>
 #include <genht/hash.h>
 #include <genlist/gendlist.h>
 #include <string.h>
@@ -190,6 +191,15 @@
 	return murmurhash(&(c), sizeof(pcb_coord_t));
 }
 
+PCB_INLINE unsigned pcb_hash_angle(const pcb_host_trans_t *tr, pcb_angle_t ang)
+{
+	long l;
+	ang -= tr->rot;
+	ang *= 10000;
+	l = floor(ang);
+	return murmurhash(&l, sizeof(l));
+}
+
 /* Return the geometric center of an object, as shown (center of bbox usually,
    but not for an arc) */
 void pcb_obj_center(const pcb_any_obj_t *obj, pcb_coord_t *x, pcb_coord_t *y);
Index: trunk/src/obj_pstk.c
===================================================================
--- trunk/src/obj_pstk.c	(revision 14728)
+++ trunk/src/obj_pstk.c	(revision 14729)
@@ -174,7 +174,19 @@
 	pcb_pstk_bbox_(dst, ps, pcb_true);
 }
 
+/* hash */
+unsigned int pcb_pstk_hash(const pcb_host_trans_t *tr, const pcb_pstk_t *p)
+{
+	unsigned int crd = 0;
+	if (!PCB_FLAG_TEST(PCB_FLAG_FLOATER, p))
+		crd = pcb_hash_cx(tr, p->x) ^ pcb_hash_cy(tr, p->y);
 
+	return pcb_hash_angle(tr, p->rot) ^ pcb_hash_coord(p->Clearance) ^
+		pcb_hash_str(p->term) ^ crd ^
+		murmurhash(&p->smirror, sizeof(p->smirror)) ^
+		murmurhash(&p->xmirror, sizeof(p->xmirror));
+}
+
 /*** utils ***/
 
 pcb_pstk_t *pcb_pstk_copy_meta(pcb_pstk_t *dst, pcb_pstk_t *src)
Index: trunk/src/obj_pstk.h
===================================================================
--- trunk/src/obj_pstk.h	(revision 14728)
+++ trunk/src/obj_pstk.h	(revision 14729)
@@ -86,6 +86,10 @@
 void pcb_pstk_bbox(pcb_pstk_t *ps);
 void pcb_pstk_copper_bbox(pcb_box_t *dst, pcb_pstk_t *ps);
 
+/* hash */
+unsigned int pcb_pstk_hash(const pcb_host_trans_t *tr, const pcb_pstk_t *p);
+
+
 void pcb_pstk_set_thermal(pcb_pstk_t *ps, unsigned long lid, unsigned char shape);
 unsigned char *pcb_pstk_get_thermal(pcb_pstk_t *ps, unsigned long lid, pcb_bool_t alloc);