From 632a60f4b7c4b08183f788b8bc991df9c40e5d88 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Wed, 7 Jan 2015 20:38:40 -0300
Subject: [PATCH] slicer/stl.c, stl.h: copy over from Neo900 misc/meme/

---
 slicer/stl.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++
 slicer/stl.h |  23 ++++++++++
 2 files changed, 143 insertions(+)
 create mode 100644 slicer/stl.c
 create mode 100644 slicer/stl.h

diff --git a/slicer/stl.c b/slicer/stl.c
new file mode 100644
index 0000000..6e1f80e
--- /dev/null
+++ b/slicer/stl.c
@@ -0,0 +1,120 @@
+/*
+ * stl.c - STL file reading
+ *
+ * Written 2014 by Werner Almesberger
+ * Copyright 2014 by Werner Almesberger
+ *
+ * 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.
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <math.h>
+
+#include "mesh.h"
+#include "stl.h"
+
+
+#define	MAX_LINE	100
+
+
+enum state {
+	s_init,
+	s_facet,
+	s_loop,
+	s_vertices,
+	s_endloop,
+	s_endfacet,
+};
+
+
+void stl_load_file(FILE *file)
+{
+	char buf[MAX_LINE+1];
+	enum state state = s_init;
+	const struct vertex *v[3];
+	int num_v = 0;
+	char *s, *e;
+	int n = 0;
+	int end, got;
+	float x, y, z;
+
+	mesh_init();
+	while (fgets(buf, sizeof(buf), file)) {
+		n++;
+		if (!(n & 1023))
+			fprintf(stderr, "%d\r", n);
+
+		for (s = buf; *s && isspace(*s); s++);
+		e = strchr(s, 0);
+		while (e != s && isspace(e[-1]))
+				e--;
+		*e = 0;
+		end = 0;
+
+		switch (state) {
+		case s_init:
+			sscanf(s, "solid %*s%n", &end);
+			state = s_facet;
+			break;
+		case s_facet:
+			if (!strncmp(s, "endsolid", 8))
+				return;
+			sscanf(s, "facet normal %*f %*f %*f%n", &end);
+			state = s_loop;
+			break;
+		case s_loop:
+			sscanf(s, "outer loop%n", &end);
+			state = s_vertices;
+			num_v = 0;
+			break;
+		case s_vertices:
+			got = sscanf(s, "vertex %f %f %f%n", &x,&y, &z, &end);
+			if (got < 3)
+				break;
+			v[num_v] = vertex_add(
+			    roundf(x*1000), roundf(-y*1000), roundf(z*1000));
+			if (++num_v == 3) {
+				facet_add(v[0], v[1], v[2]);
+				state = s_endloop;
+			}
+			break;
+		case s_endloop:
+			sscanf(s, "endloop%n", &end);
+			state = s_endfacet;
+			break;
+		case s_endfacet:
+			sscanf(s, "endfacet%n", &end);
+			state = s_facet;
+			break;
+		}
+		if (end != e-s) {
+			fprintf(stderr, "cannot parse line %d (%d %ld)\n",
+			     n, end, e-s);
+			exit(1);
+		}
+	}
+	fprintf(stderr, "incomplete STL file\n");
+	exit(1);
+
+}
+
+
+void stl_load(const char *name)
+{
+	FILE *file;
+
+	file = fopen(name, "r");
+	if (!file) {
+		perror(name);
+		exit(1);
+	}
+	stl_load_file(file);
+	fclose(file);
+}
diff --git a/slicer/stl.h b/slicer/stl.h
new file mode 100644
index 0000000..e1db1c4
--- /dev/null
+++ b/slicer/stl.h
@@ -0,0 +1,23 @@
+/*
+ * stl.h - STL file reading
+ *
+ * Written 2014 by Werner Almesberger
+ * Copyright 2014 by Werner Almesberger
+ *
+ * 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.
+ */
+
+
+#ifndef STL_H
+#define	STL_H
+
+#include <stdio.h>
+
+
+void stl_load_file(FILE *file);
+void stl_load(const char *name);
+
+#endif /* !STL_H */