Index: trunk/src_plugins/export_stl/stl_models.c
===================================================================
--- trunk/src_plugins/export_stl/stl_models.c	(nonexistent)
+++ trunk/src_plugins/export_stl/stl_models.c	(revision 32428)
@@ -0,0 +1,153 @@
+/*
+ *                            COPYRIGHT
+ *
+ *  pcb-rnd, interactive printed circuit board design
+ *  Copyright (C) 2020 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 <stdlib.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+
+#include "safe_fs.h"
+#include "error.h"
+
+typedef struct stl_facet_s stl_facet_t;
+
+struct stl_facet_s {
+	double nx, ny, nz;
+	double vx[3], vy[3], vz[3];
+	stl_facet_t *next;
+};
+
+static char *stl_getline(char *line, int linelen, FILE *f)
+{
+	char *cmd;
+	while((cmd = fgets(line, linelen, f)) != NULL) {
+		while(isspace(*cmd)) cmd++;
+		if (*cmd == '\0') continue;
+		return cmd;
+	}
+	return NULL;
+}
+
+void stl_solid_free(stl_facet_t *head)
+{
+	stl_facet_t *next;
+	for(; head != NULL; head = next) {
+		next = head->next;
+		free(head);
+	}
+}
+
+stl_facet_t *stl_solid_load(rnd_hidlib_t *hl, const char *fn)
+{
+	FILE *f;
+	stl_facet_t *head = NULL, *tail = NULL, *t;
+	char *cmd, line[512];
+
+	f = rnd_fopen(hl, fn, "r");
+	if (f == NULL)
+		return NULL;
+
+	/* find the 'solid' header */
+	cmd = stl_getline(line, sizeof(line), f);
+	if ((cmd == NULL) || (strncmp(cmd, "solid", 5) != 0)) {
+		rnd_message(RND_MSG_ERROR, "Invalid stl file: first line is not a 'solid'\n");
+		goto err0;
+	}
+
+	for(;;) {
+		int n;
+
+		cmd = stl_getline(line, sizeof(line), f);
+		if (cmd == NULL) {
+			rnd_message(RND_MSG_ERROR, "Invalid stl file: premature end of file in solid\n");
+			goto err1;
+		}
+		if (strncmp(cmd, "endsolid", 8) == 0)
+			break; /* normal end of file */
+
+		if (strncmp(cmd, "facet normal", 12) != 0) {
+			rnd_message(RND_MSG_ERROR, "Invalid stl file: expected facet, got %s\n", cmd);
+			goto err1;
+		}
+
+		t = malloc(sizeof(stl_facet_t));
+		t->next = NULL;
+		if (tail != NULL) {
+			tail->next = t;
+			tail = t;
+		}
+		else
+			head = tail = t;
+
+		cmd += 12;
+		if (sscanf(cmd, "%lf %lf %lf", &t->nx, &t->ny, &t->nz) != 3) {
+			rnd_message(RND_MSG_ERROR, "Invalid stl file: wrong facet normals '%s'\n", cmd);
+			goto err1;
+		}
+
+		cmd = stl_getline(line, sizeof(line), f);
+		if (strncmp(cmd, "outer loop", 10) != 0) {
+			rnd_message(RND_MSG_ERROR, "Invalid stl file: expected outer loop, got %s\n", cmd);
+			goto err1;
+		}
+
+		for(n = 0; n < 3; n++) {
+			cmd = stl_getline(line, sizeof(line), f);
+			if (strncmp(cmd, "vertex", 6) != 0) {
+				rnd_message(RND_MSG_ERROR, "Invalid stl file: expected vertex, got %s\n", cmd);
+				goto err1;
+			}
+			cmd+=6;
+			if (sscanf(cmd, "%lf %lf %lf", &t->vx[n], &t->vy[n], &t->vz[n]) != 3) {
+				rnd_message(RND_MSG_ERROR, "Invalid stl file: wrong facet vertex '%s'\n", cmd);
+				goto err1;
+			}
+		}
+
+		cmd = stl_getline(line, sizeof(line), f);
+		if (strncmp(cmd, "endloop", 7) != 0) {
+			rnd_message(RND_MSG_ERROR, "Invalid stl file: expected endloop, got %s\n", cmd);
+			goto err1;
+		}
+
+		cmd = stl_getline(line, sizeof(line), f);
+		if (strncmp(cmd, "endfacet", 8) != 0) {
+			rnd_message(RND_MSG_ERROR, "Invalid stl file: expected endfacet, got %s\n", cmd);
+			goto err1;
+		}
+	}
+
+
+	fclose(f);
+	err0:;
+	return head;
+
+	err1:;
+	stl_solid_free(head);
+	fclose(f);
+	return NULL;
+}