Index: trunk/src/data.h
===================================================================
--- trunk/src/data.h	(revision 6283)
+++ trunk/src/data.h	(revision 6284)
@@ -54,11 +54,7 @@
 
 
 #define pcb_max_layer (PCB->Data->LayerN)
-
-/* OBSOLOTE: do not use these 4 */
 #define pcb_max_group (PCB->LayerGroups.len)
-#define pcb_layer_get_bottom_silk()   (pcb_max_layer + PCB_SOLDER_SIDE - 2)
-#define pcb_layer_get_top_silk()      (pcb_max_layer + PCB_COMPONENT_SIDE - 2)
 
 extern pcb_buffer_t pcb_buffers[PCB_MAX_BUFFER];
 extern int pcb_added_lines;
Index: trunk/src/layer.c
===================================================================
--- trunk/src/layer.c	(revision 6283)
+++ trunk/src/layer.c	(revision 6284)
@@ -720,3 +720,38 @@
 	return 1;
 }
 
+static pcb_layer_id_t pcb_layer_get_cached(pcb_layer_id_t *cache, unsigned int loc, unsigned int typ)
+{
+	pcb_layer_group_t *g;
+
+	if (*cache < pcb_max_layer) { /* check if the cache is still pointing to the right layer */
+		pcb_layergrp_id_t gid = PCB->Data->Layer[*cache].grp;
+		if ((gid >= 0) && (gid < PCB->LayerGroups.len)) {
+			g = &(PCB->LayerGroups.grp[gid]);
+			if ((g->type & loc) && (g->type & typ) && (g->lid[0] == *cache))
+				return *cache;
+		}
+	}
+
+	/* nope: need to resolve it again */
+	g = pcb_get_grp(&PCB->LayerGroups, loc, typ);
+	if ((g == NULL) || (g->len == 0)) {
+		*cache = -1;
+		return -1;
+	}
+	*cache = g->lid[0];
+	return *cache;
+}
+
+pcb_layer_id_t pcb_layer_get_bottom_silk()
+{
+	static pcb_layer_id_t cache = -1;
+	return pcb_layer_get_cached(&cache, PCB_LYT_BOTTOM, PCB_LYT_SILK);
+}
+
+pcb_layer_id_t pcb_layer_get_top_silk()
+{
+	static pcb_layer_id_t cache = -1;
+	return pcb_layer_get_cached(&cache, PCB_LYT_TOP, PCB_LYT_SILK);
+}
+
Index: trunk/src/layer.h
===================================================================
--- trunk/src/layer.h	(revision 6283)
+++ trunk/src/layer.h	(revision 6284)
@@ -121,6 +121,11 @@
 pcb_bool pcb_layer_is_paste_empty(pcb_side_t side);
 
 
+/* Cached lookup of the first silk layer in the bottom or top group */
+pcb_layer_id_t pcb_layer_get_bottom_silk();
+pcb_layer_id_t pcb_layer_get_top_silk();
+
+
 /************ OLD API - new code should not use these **************/
 
 #define	LAYER_ON_STACK(n)	(&PCB->Data->Layer[pcb_layer_stack[(n)]])