Index: trunk/src/obj_arc.c
===================================================================
--- trunk/src/obj_arc.c	(revision 14720)
+++ trunk/src/obj_arc.c	(revision 14721)
@@ -282,11 +282,11 @@
 	return 1;
 }
 
-unsigned int pcb_subc_arc_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_arc_t *a)
+unsigned int pcb_arc_hash(const pcb_host_trans_t *tr, const pcb_arc_t *a)
 {
 	unsigned int crd = 0;
 	if (!PCB_FLAG_TEST(PCB_FLAG_FLOATER, a))
-		crd = pcb_hash_coord(a->X-ox) ^ pcb_hash_coord(a->Y-oy);
+		crd = pcb_hash_cx(tr, a->X) ^ pcb_hash_cy(tr, a->Y);
 
 	return 
 		pcb_hash_coord(a->Thickness) ^ pcb_hash_coord(a->Clearance) ^
Index: trunk/src/obj_arc.h
===================================================================
--- trunk/src/obj_arc.h	(revision 14720)
+++ trunk/src/obj_arc.h	(revision 14721)
@@ -67,7 +67,7 @@
 
 /*** hash ***/
 int pcb_arc_eq(const pcb_element_t *e1, const pcb_arc_t *a1, const pcb_element_t *e2, const pcb_arc_t *a2);
-unsigned int pcb_subc_arc_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_arc_t *a);
+unsigned int pcb_arc_hash(const pcb_host_trans_t *tr, const pcb_arc_t *a);
 
 
 /* Return the x;y coordinate of the endpoint of an arc; if which is 0, return
Index: trunk/src/obj_common.h
===================================================================
--- trunk/src/obj_common.h	(revision 14720)
+++ trunk/src/obj_common.h	(revision 14721)
@@ -93,6 +93,15 @@
 
 int pcb_obj_get_bbox(int Type, void *Ptr1, void *Ptr2, void *Ptr3, pcb_box_t *res);
 
+/* Host transformations: typically the transformations an object of a subc
+   inherits from the subc */
+typedef struct pcb_host_trans_s {
+	pcb_coord_t ox, oy;
+	int on_bottom;
+	double rot;
+	double cosa, sina; /* rot angle cache */
+} pcb_host_trans_t;
+
 /* memset object to 0, but keep the link field */
 #define reset_obj_mem(type, obj) \
 do { \
@@ -169,6 +178,18 @@
 	return murmurhash(&(c), sizeof(pcb_coord_t));
 }
 
+PCB_INLINE unsigned pcb_hash_cx(const pcb_host_trans_t *tr, pcb_coord_t c)
+{
+	c -= tr->ox;
+	return murmurhash(&(c), sizeof(pcb_coord_t));
+}
+
+PCB_INLINE unsigned pcb_hash_cy(const pcb_host_trans_t *tr, pcb_coord_t c)
+{
+	c -= tr->oy;
+	return murmurhash(&(c), sizeof(pcb_coord_t));
+}
+
 /* 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_line.c
===================================================================
--- trunk/src/obj_line.c	(revision 14720)
+++ trunk/src/obj_line.c	(revision 14721)
@@ -281,12 +281,12 @@
 }
 
 
-unsigned int pcb_subc_line_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_line_t *l)
+unsigned int pcb_line_hash(const pcb_host_trans_t *tr, const pcb_line_t *l)
 {
 	unsigned int crd = 0;
 	if (!PCB_FLAG_TEST(PCB_FLAG_FLOATER, l))
-		crd = pcb_hash_coord(l->Point1.X-ox) ^ pcb_hash_coord(l->Point1.Y-oy) ^
-			pcb_hash_coord(l->Point2.X-ox) ^ pcb_hash_coord(l->Point2.Y-oy);
+		crd = pcb_hash_cx(tr, l->Point1.X) ^ pcb_hash_cy(tr, l->Point1.Y) ^
+			pcb_hash_cx(tr, l->Point2.X) ^ pcb_hash_cy(tr, l->Point2.Y);
 
 	return pcb_hash_coord(l->Thickness) ^ pcb_hash_coord(l->Clearance) ^
 		pcb_hash_str(l->term) ^ crd;
Index: trunk/src/obj_line.h
===================================================================
--- trunk/src/obj_line.h	(revision 14720)
+++ trunk/src/obj_line.h	(revision 14721)
@@ -75,7 +75,7 @@
 
 /* hash */
 int pcb_line_eq(const pcb_element_t *e1, const pcb_line_t *l1, const pcb_element_t *e2, const pcb_line_t *l2);
-unsigned int pcb_subc_line_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_line_t *l);
+unsigned int pcb_line_hash(const pcb_host_trans_t *tr, const pcb_line_t *l);
 
 
 /*** DRC enforcement (obj_line_drcenf.c) ***/
Index: trunk/src/obj_poly.c
===================================================================
--- trunk/src/obj_poly.c	(revision 14720)
+++ trunk/src/obj_poly.c	(revision 14721)
@@ -209,7 +209,7 @@
 }
 #endif
 
-unsigned int pcb_subc_poly_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_poly_t *p)
+unsigned int pcb_subc_poly_hash(const pcb_host_trans_t *tr, const pcb_poly_t *p)
 {
 	unsigned int crd = 0;
 	pcb_cardinal_t n;
@@ -216,7 +216,7 @@
 
 	if (!PCB_FLAG_TEST(PCB_FLAG_FLOATER, p))
 		for(n = 0; n < p->PointN; n++)
-			crd ^= pcb_hash_coord(p->Points[n].X-ox) ^ pcb_hash_coord(p->Points[n].Y-oy);
+			crd ^= pcb_hash_cx(tr, p->Points[n].X) ^ pcb_hash_cy(tr, p->Points[n].Y);
 
 	return pcb_hash_coord(p->Clearance) ^ pcb_hash_str(p->term) ^ crd;
 }
Index: trunk/src/obj_poly.h
===================================================================
--- trunk/src/obj_poly.h	(revision 14720)
+++ trunk/src/obj_poly.h	(revision 14721)
@@ -77,7 +77,7 @@
 pcb_poly_t *pcb_poly_copy(pcb_poly_t *Dest, pcb_poly_t *Src, pcb_coord_t dx, pcb_coord_t dy);
 
 /* hash */
-unsigned int pcb_subc_poly_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_poly_t *p);
+unsigned int pcb_poly_hash(const pcb_host_trans_t *tr, const pcb_poly_t *p);
 
 /* Add objects without creating them or making any "sanity modifications" to them */
 void pcb_add_poly_on_layer(pcb_layer_t *Layer, pcb_poly_t *polygon);
Index: trunk/src/obj_text.c
===================================================================
--- trunk/src/obj_text.c	(revision 14720)
+++ trunk/src/obj_text.c	(revision 14721)
@@ -343,11 +343,11 @@
 }
 #endif
 
-unsigned int pcb_subc_text_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_text_t *t)
+unsigned int pcb_text_hash(const pcb_host_trans_t *tr, const pcb_text_t *t)
 {
 	unsigned int crd = 0;
 	if (!PCB_FLAG_TEST(PCB_FLAG_FLOATER, t))
-		crd = pcb_hash_coord(t->X-ox) ^ pcb_hash_coord(t->Y-oy) ^ pcb_hash_coord(t->Scale);
+		crd = pcb_hash_cx(tr, t->X) ^ pcb_hash_cy(tr, t->Y) ^ pcb_hash_coord(t->Scale);
 
 	return pcb_hash_str(t->TextString) ^ pcb_hash_str(t->term) ^ crd;
 }
Index: trunk/src/obj_text.h
===================================================================
--- trunk/src/obj_text.h	(revision 14720)
+++ trunk/src/obj_text.h	(revision 14721)
@@ -73,7 +73,7 @@
 void pcb_text_dyn_bbox_update(pcb_data_t *data);
 
 /* hash */
-unsigned int pcb_subc_text_hash(pcb_coord_t ox, pcb_coord_t oy, const pcb_text_t *t);
+unsigned int pcb_text_hash(const pcb_host_trans_t *tr, const pcb_text_t *t);
 
 /* Append dyntext fmt rendered from the perspective of obj */
 int pcb_append_dyntext(gds_t *dst, pcb_any_obj_t *obj, const char *fmt);