Big endian fix, thanks to @hyperair for hints and initial implementation.

1 files changed, 16 insertions, 2 deletions

diff --git a/xs/src/admesh/stlinit.cpp b/xs/src/admesh/stlinit.cpp
index f5110d394..84fc8d2c1 100644
--- a/xs/src/admesh/stlinit.cpp
+++ b/xs/src/admesh/stlinit.cpp
@@ -27,6 +27,7 @@
 #include <assert.h>
 
 #include <boost/nowide/cstdio.hpp>
+#include <boost/detail/endian.hpp>
 
 #include "stl.h"
 
@@ -50,11 +51,15 @@ stl_initialize(stl_file *stl) {
   stl->stats.volume = -1.0;
 }
 
+#ifndef BOOST_LITTLE_ENDIAN
+extern void stl_internal_reverse_quads(char *buf, size_t cnt);
+#endif /* BOOST_LITTLE_ENDIAN */
+
 void
 stl_count_facets(stl_file *stl, const char *file) {
   long           file_size;
   int            header_num_facets;
-  int            num_facets;
+  uint32_t       num_facets;
   int            i;
   size_t         s;
   unsigned char  chtest[128];
@@ -113,7 +118,12 @@ stl_count_facets(stl_file *stl, const char *file) {
     }
 
     /* Read the int following the header.  This should contain # of facets */
-    if((!fread(&header_num_facets, sizeof(int), 1, stl->fp)) || (num_facets != header_num_facets)) {
+    bool header_num_faces_read = fread(&header_num_facets, sizeof(uint32_t), 1, stl->fp);
+#ifndef BOOST_LITTLE_ENDIAN
+    // Convert from little endian to big endian.
+    stl_internal_reverse_quads((char*)&header_num_facets, 4);
+#endif /* BOOST_LITTLE_ENDIAN */
+    if (! header_num_faces_read || num_facets != header_num_facets) {
       fprintf(stderr,
               "Warning: File size doesn't match number of facets in the header\n");
     }
@@ -268,6 +278,10 @@ stl_read(stl_file *stl, int first_facet, int first) {
         stl->error = 1;
         return;
       }
+#ifndef BOOST_LITTLE_ENDIAN
+      // Convert the loaded little endian data to big endian.
+      stl_internal_reverse_quads((char*)&facet, 48);
+#endif /* BOOST_LITTLE_ENDIAN */
     } else
       /* Read a single facet from an ASCII .STL file */
     {