Index: trunk/src/data_it.h
===================================================================
--- trunk/src/data_it.h	(nonexistent)
+++ trunk/src/data_it.h	(revision 13519)
@@ -0,0 +1,140 @@
+/*
+ *                            COPYRIGHT
+ *
+ *  pcb-rnd, interactive printed circuit board design
+ *  Copyright (C) 2017 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.
+ *
+ */
+
+/* Flat, non-recursive iterator on pcb_data_t children objects */
+
+#ifndef PCB_DATA_IT_H
+#define PCB_DATA_IT_H
+
+#include "obj_common.h"
+#include "data.h"
+
+typedef struct pcb_data_it_s {
+	/* config */
+	pcb_data_t *data;
+	pcb_obj_type_t mask; /* caller wants to see these types */
+
+	/* current state */
+	pcb_obj_type_t remaining;
+	pcb_obj_type_t type;
+	pcb_cardinal_t ln;
+	pcb_any_obj_t *last;
+} pcb_data_it_t;
+
+#define PCB_DATA_IT_TYPES \
+	(PCB_OBJ_LINE | PCB_OBJ_TEXT | PCB_OBJ_POLY | PCB_OBJ_ARC | PCB_OBJ_PSTK | \
+	PCB_OBJ_SUBC | PCB_OBJ_RAT)
+
+/* Start an iteration on data, looking for any object type listed in mask;
+   returns NULL if nothing is found. The iteration is non-recursive to subcircuits */
+PCB_INLINE pcb_any_obj_t *pcb_data_first(pcb_data_it_t *it, pcb_data_t *data, pcb_obj_type_t mask);
+
+/* Return the next object or NULL on end of iteration */
+PCB_INLINE pcb_any_obj_t *pcb_data_next(pcb_data_it_t *it);
+
+/**** implementation (inlines) ****/
+
+/* Skip to the next type; returns 0 on success, non-0 at the end of types */
+PCB_INLINE int pcb_data_it_next_type(pcb_data_it_t *it)
+{
+	if (it->remaining == 0)
+		return 1;
+
+	if (it->type == 0)
+		it->type = 1;
+	else
+		it->type <<= 1;
+
+	/* find and remove the next bit */
+	while((it->remaining & it->type) == 0) it->type <<= 1;
+	it->remaining &= ~it->type;
+
+	return 0;
+}
+
+/* Take the next layer object, skip layer if there's no more */
+#define PCB_DATA_IT_LOBJ(it, otype, ltype, list) \
+	do { \
+		if (it->last == NULL) \
+			it->last = (pcb_any_obj_t *)ltype ## _first(&(it->data->Layer[it->ln].list)); \
+		else \
+			it->last = (pcb_any_obj_t *)ltype ## _next((otype *)it->last); \
+		if (it->last == NULL) \
+			goto next_layer; \
+	} while(0)
+
+/* Take the next global object, skip type if there's no more */
+#define PCB_DATA_IT_GOBJ(it, otype, ltype, list) \
+	do { \
+		if (it->last == NULL) \
+			it->last = (pcb_any_obj_t *)ltype ## _first(&(it->data->list)); \
+		else \
+			it->last = (pcb_any_obj_t *)ltype ## _next((otype *)it->last); \
+		if (it->last == NULL) \
+			goto next_type; \
+	} while(0)
+
+
+PCB_INLINE pcb_any_obj_t *pcb_data_next(pcb_data_it_t *it)
+{
+	retry:;
+
+	switch(it->type) {
+		case PCB_OBJ_LINE: PCB_DATA_IT_LOBJ(it, pcb_line_t, linelist, Line); break;
+		case PCB_OBJ_TEXT: PCB_DATA_IT_LOBJ(it, pcb_text_t, textlist, Text); break;
+		case PCB_OBJ_POLY: PCB_DATA_IT_LOBJ(it, pcb_poly_t, polylist, Polygon); break;
+		case PCB_OBJ_ARC:  PCB_DATA_IT_LOBJ(it, pcb_arc_t,  arclist,  Arc); break;
+		case PCB_OBJ_PSTK: PCB_DATA_IT_GOBJ(it, pcb_pstk_t, padstacklist, padstack); break;
+		case PCB_OBJ_SUBC: PCB_DATA_IT_GOBJ(it, pcb_subc_t, pcb_subclist, subc); break;
+		case PCB_OBJ_RAT:  PCB_DATA_IT_GOBJ(it, pcb_rat_t,  ratlist, Rat); break;
+		default:
+			assert(!"iterating on invalid type");
+			return NULL;
+	}
+	return it->last;
+
+	/* skip to the next layer and retry unless ran out of types */
+	next_layer:;
+	it->ln++;
+	if (it->ln >= it->data->LayerN) { /* checked all layers for this type, skip to next type */
+		it->ln = 0;
+		next_type:;
+		if (pcb_data_it_next_type(it))
+			return NULL;
+	}
+
+	goto retry; /* ... on the new layer */
+}
+
+PCB_INLINE pcb_any_obj_t *pcb_data_first(pcb_data_it_t *it, pcb_data_t *data, pcb_obj_type_t mask)
+{
+	it->data = data;
+	it->mask = it->remaining = mask & PCB_DATA_IT_TYPES;
+	it->type = 0;
+	it->ln = 0;
+	it->last = NULL;
+	if (pcb_data_it_next_type(it))
+		return NULL;
+	return pcb_data_next(it);
+}
+
+#endif