Index: Plug.tmpasm
===================================================================
--- Plug.tmpasm	(revision 22263)
+++ Plug.tmpasm	(revision 22264)
@@ -1,6 +1,7 @@
 put /local/pcb/mod {lib_netmap}
 put /local/pcb/mod/OBJS [@
 	$(PLUGDIR)/lib_netmap/netmap.o
+	$(PLUGDIR)/lib_netmap/placement.o
 @]
 
 switch /local/pcb/lib_netmap/controls
Index: placement.c
===================================================================
--- placement.c	(nonexistent)
+++ placement.c	(revision 22264)
@@ -0,0 +1,53 @@
+/*
+ *                            COPYRIGHT
+ *
+ *  pcb-rnd, interactive printed circuit board design
+ *  Copyright (C) 2019 Tibor 'Igor2' Palinkas
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *  Contact:
+ *    Project page: http://repo.hu/projects/pcb-rnd
+ *    lead developer: http://repo.hu/projects/pcb-rnd/contact.html
+ *    mailing list: pcb-rnd (at) list.repo.hu (send "subscribe")
+ */
+
+#include "config.h"
+#include "placement.h"
+
+void pcb_placement_init(pcb_placement_t *ctx, pcb_board_t *pcb)
+{
+	memset(ctx, 0, sizeof(pcb_placement_t));
+	htscp_init(&ctx->subcs, pcb_subc_hash, pcb_subc_eq);
+	pcb_data_init(&ctx->data);
+	pcb_data_bind_board_layers(pcb, &ctx->data, 0);
+	ctx->pcb = pcb;
+}
+
+void pcb_placement_uninit(pcb_placement_t *ctx)
+{
+	htscp_uninit(&ctx->subcs);
+	pcb_data_uninit(&ctx->data);
+}
+
+void pcb_placement_build(pcb_placement_t *ctx, pcb_data_t *data)
+{
+	PCB_SUBC_LOOP(data) {
+		if (!htscp_has(&ctx->subcs, subc)) {
+			htscp_insert(&ctx->subcs, subc, subc);
+		}
+	}
+	PCB_END_LOOP;
+}
Index: placement.h
===================================================================
--- placement.h	(nonexistent)
+++ placement.h	(revision 22264)
@@ -0,0 +1,13 @@
+#include "board.h"
+#include "data.h"
+#include "ht_subc.h"
+
+typedef struct {
+	htscp_t subcs;
+	pcb_board_t *pcb;
+	pcb_data_t data; /* temp buffer to place prototype subcs in */
+} pcb_placement_t;
+
+void pcb_placement_init(pcb_placement_t *ctx, pcb_board_t *pcb);
+void pcb_placement_uninit(pcb_placement_t *ctx);
+void pcb_placement_build(pcb_placement_t *ctx, pcb_data_t *data);