Support MTL files with escaped whitespace

examples/viewer/README.md

@@ -5,6 +5,8 @@
 * premake5
 * glfw3
 * glew
+* xcursor
+* xinerama
 
 ## Build on MaCOSX
 

models/mtl filename with whitespace issue46.mtl

@@ -0,0 +1,4 @@
+newmtl green
+Ka 0 0 0
+Kd 0 1 0
+Ks 0 0 0

models/mtl filename with whitespace issue46.obj

@@ -0,0 +1,31 @@
+mtllib invalid-file-without-spaces.mtl invalid\ file\ with\ spaces.mtl  mtl\ filename\ with\ whitespace\ issue46.mtl
+
+v 0.000000 2.000000 2.000000
+v 0.000000 0.000000 2.000000
+v 2.000000 0.000000 2.000000
+v 2.000000 2.000000 2.000000
+v 0.000000 2.000000 0.000000
+v 0.000000 0.000000 0.000000
+v 2.000000 0.000000 0.000000
+v 2.000000 2.000000 0.000000
+# 8 vertices
+
+g front cube
+usemtl green
+f 1 2 3 4
+g back cube
+usemtl green
+f 8 7 6 5
+g right cube
+usemtl green
+f 4 3 7 8
+g left cube
+usemtl green
+f 5 6 2 1
+g top cube
+usemtl green
+f 5 1 4 8
+g bottom cube
+usemtl green
+f 2 6 7 3
+# 6 elements

tests/tester.cc

@@ -1308,6 +1308,30 @@ void test_texres_texopt_issue248() {
   TEST_CHECK("input.jpg" == materials[0].diffuse_texname);
 }
 
+void test_mtl_filename_with_whitespace_issue46() {
+  tinyobj::attrib_t attrib;
+  std::vector<tinyobj::shape_t> shapes;
+  std::vector<tinyobj::material_t> materials;
+
+  std::string warn;
+  std::string err;
+  bool ret =
+      tinyobj::LoadObj(&attrib, &shapes, &materials, &warn, &err,
+                       "../models/mtl filename with whitespace issue46.obj",
+                       gMtlBasePath);
+
+  if (!warn.empty()) {
+    std::cout << "WARN: " << warn << std::endl;
+  }
+
+  if (!err.empty()) {
+    std::cerr << "ERR: " << err << std::endl;
+  }
+  TEST_CHECK(true == ret);
+  TEST_CHECK(1 == materials.size());
+  TEST_CHECK("green" == materials[0].name);
+}
+
 // Fuzzer test.
 // Just check if it does not crash.
 // Disable by default since Windows filesystem can't create filename of afl
@@ -1407,4 +1431,6 @@ TEST_LIST = {
      test_usemtl_whitespace_issue246},
     {"texres_texopt_issue248",
      test_texres_texopt_issue248},
+    {"test_mtl_filename_with_whitespace_issue46",
+     test_mtl_filename_with_whitespace_issue46},
     {NULL, NULL}};

tiny_obj_loader.h

@@ -1658,16 +1658,31 @@ static bool exportGroupsToShape(shape_t *shape, const PrimGroup &prim_group,
   return true;
 }
 
-// Split a string with specified delimiter character.
-// http://stackoverflow.com/questions/236129/split-a-string-in-c
-static void SplitString(const std::string &s, char delim,
+// Split a string with specified delimiter character and escape character.
+// https://rosettacode.org/wiki/Tokenize_a_string_with_escaping#C.2B.2B
+static void SplitString(const std::string &s, char delim, char escape,
                         std::vector<std::string> &elems) {
-  std::stringstream ss;
-  ss.str(s);
-  std::string item;
-  while (std::getline(ss, item, delim)) {
-    elems.push_back(item);
+  std::string token;
+
+  bool escaping = false;
+  for (int i = 0; i < s.size(); ++i) {
+    char ch = s[i];
+    if (escaping) {
+      escaping = false;
+    } else if (ch == escape) {
+      escaping = true;
+      continue;
+    } else if (ch == delim) {
+      if (!token.empty()) {
+        elems.push_back(token);
+      }
+      token.clear();
+      continue;
+    }
+    token += ch;
   }
+
+  elems.push_back(token);
 }
 
 static std::string JoinPath(const std::string &dir,
@@ -2483,7 +2498,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
         token += 7;
 
         std::vector<std::string> filenames;
-        SplitString(std::string(token), ' ', filenames);
+        SplitString(std::string(token), ' ', '\\', filenames);
 
         if (filenames.empty()) {
           if (warn) {
@@ -2891,7 +2906,7 @@ bool LoadObjWithCallback(std::istream &inStream, const callback_t &callback,
         token += 7;
 
         std::vector<std::string> filenames;
-        SplitString(std::string(token), ' ', filenames);
+        SplitString(std::string(token), ' ', '\\', filenames);
 
         if (filenames.empty()) {
           if (warn) {