From c82ea10493e560499e7b90e59092005e22ffb3c3 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Thu, 8 Jan 2015 00:15:37 -0300
Subject: [PATCH] slicer/stl.c (stl_load_file): support binary STL as well (on
 little-endian hosts)

---
 slicer/stl.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 2 deletions(-)

diff --git a/slicer/stl.c b/slicer/stl.c
index 1590f50..074f6b1 100644
--- a/slicer/stl.c
+++ b/slicer/stl.c
@@ -11,6 +11,7 @@
  */
 
 
+#include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <ctype.h>
@@ -33,7 +34,53 @@ enum state {
 };
 
 
-void stl_load_file(FILE *file, void (*facet)(struct v f[3]))
+static void stl_load_binary(FILE *file, void (*facet)(struct v f[3]))
+{
+	char discard[75];
+	size_t n;
+	uint32_t nf;
+	uint16_t attr;
+	float tmp[4*3];
+	struct v f[3];
+	int i;
+
+	n = fread(discard, 1, sizeof(discard), file);
+	if (n != sizeof(discard)) {
+		fprintf(stderr, "incomplete header\n");
+		exit(1);
+	}
+	n = fread(&nf, 1, sizeof(nf), file);
+	if (n != sizeof(nf)) {
+		fprintf(stderr, "no number of facets\n");
+		exit(1);
+	}
+fprintf(stderr, "nf %u\n", (unsigned) nf);
+	while (nf--) {
+		n = fread(&tmp, 1, sizeof(tmp), file);
+		if (n != sizeof(tmp)) {
+			fprintf(stderr, "incomplete facet\n");
+			exit(1);
+		}
+		for (i = 0; i != 3; i++) {
+			f[i].x = tmp[3 * i + 3];
+			f[i].y = tmp[3 * i + 4];
+			f[i].z = tmp[3 * i + 5];
+		}
+		facet(f);
+		n = fread(&attr, 1, sizeof(attr), file);
+		if (n != sizeof(attr)) {
+			fprintf(stderr, "no attribute count\n");
+			exit(1);
+		}
+		if (attr) {
+			fprintf(stderr, "non-zero attribute count\n");
+			exit(1);
+		}
+	}
+}
+
+
+static void stl_load_text(FILE *file, void (*facet)(struct v f[3]))
 {
 	char buf[MAX_LINE + 1];
 	enum state state = s_init;
@@ -57,7 +104,7 @@ void stl_load_file(FILE *file, void (*facet)(struct v f[3]))
 
 		switch (state) {
 		case s_init:
-			sscanf(s, "solid %*s%n", &end);
+			sscanf(s, " %*s%n", &end);
 			state = s_facet;
 			break;
 		case s_facet:
@@ -102,6 +149,25 @@ void stl_load_file(FILE *file, void (*facet)(struct v f[3]))
 }
 
 
+void stl_load_file(FILE *file, void (*facet)(struct v f[3]))
+{
+	char buf[5];
+	size_t n;
+
+	n = fread(buf, 1, sizeof(buf), file);
+	if (n != sizeof(buf)) {
+		fprintf(stderr, "file too short\n");
+		exit(1);
+	}
+
+	if (memcmp(buf, "solid", 5)) {
+		stl_load_binary(file, facet);
+	} else {
+		stl_load_text(file, facet);
+	}
+}
+
+
 void stl_load(const char *name, void (*facet)(struct v f[3]))
 {
 	FILE *file;