Replace non-leading tabs with spaces, using:

find -type f |  # list all regular files
  grep -E '\.(h|cpp|mm)$' |  # filter for source files
  grep -v '/mt_' |  # filter out generated files
  grep -v '/vendor/' | # and vendored GL
  xargs -n 1 -P $(nproc) ./replace_non_leading_tabs.lua  # reformat everything

source/Irrlicht/CImageLoaderJPG.h

@@ -6,7 +6,7 @@
 
 #include "IImageLoader.h"
 
-#include <cstdio>	 // required for jpeglib.h
+#include <cstdio>    // required for jpeglib.h
 #include <jpeglib.h> // use system lib
 #include <setjmp.h>