extern: Fix fast_obj to trim trainling whitespace for names

Some .obj files have extra whitespace after usemtl and other statements;
this may interfere with parsing, for example by adding a space to the
material name which can result in inability to find it in .mtl file.

extern/fast_obj.h

@@ -410,12 +410,6 @@ int is_whitespace(char c)
     return (c == ' ' || c == '\t' || c == '\r');
 }
 
-static
-int is_end_of_name(char c)
-{
-    return (c == '\t' || c == '\r' || c == '\n');
-}
-
 static
 int is_newline(char c)
 {
@@ -437,6 +431,21 @@ int is_exponent(char c)
 }
 
 
+static
+const char* skip_name(const char* ptr)
+{
+    const char* s = ptr;
+
+    while (!is_newline(*ptr))
+        ptr++;
+
+    while (ptr > s && is_whitespace(*(ptr - 1)))
+        ptr--;
+
+    return ptr;
+}
+
+
 static
 const char* skip_whitespace(const char* ptr)
 {
@@ -771,9 +780,7 @@ const char* parse_object(fastObjData* data, const char* ptr)
     ptr = skip_whitespace(ptr);
 
     s = ptr;
-    while (!is_end_of_name(*ptr))
-        ptr++;
-
+    ptr = skip_name(ptr);
     e = ptr;
 
     flush_object(data);
@@ -793,9 +800,7 @@ const char* parse_group(fastObjData* data, const char* ptr)
     ptr = skip_whitespace(ptr);
 
     s = ptr;
-    while (!is_end_of_name(*ptr))
-        ptr++;
-
+    ptr = skip_name(ptr);
     e = ptr;
 
     flush_group(data);
@@ -874,9 +879,7 @@ const char* parse_usemtl(fastObjData* data, const char* ptr)
 
     /* Parse the material name */
     s = ptr;
-    while (!is_end_of_name(*ptr))
-        ptr++;
-
+    ptr = skip_name(ptr);
     e = ptr;
 
     /* Find an existing material with the same name */
@@ -972,9 +975,7 @@ const char* read_map(fastObjData* data, const char* ptr, fastObjTexture* map)
 
     /* Read name */
     s = ptr;
-    while (!is_end_of_name(*ptr))
-        ptr++;
-
+    ptr = skip_name(ptr);
     e = ptr;
 
     name = string_copy(s, e);
@@ -1048,8 +1049,7 @@ int read_mtllib(fastObjData* data, void* file, const fastObjCallbacks* callbacks
                     p++;
 
                 s = p;
-                while (!is_end_of_name(*p))
-                    p++;
+                p = skip_name(p);
 
                 mtl.name = string_copy(s, p);
             }
@@ -1191,9 +1191,7 @@ const char* parse_mtllib(fastObjData* data, const char* ptr, const fastObjCallba
     ptr = skip_whitespace(ptr);
 
     s = ptr;
-    while (!is_end_of_name(*ptr))
-        ptr++;
-
+    ptr = skip_name(ptr);
     e = ptr;
 
     lib = string_concat(data->base, s, e);