#! /bin/sh
set -eu

[ -n "${CPP}" ] && [ -n "$PROJROOT" ] \
	|| { echo "Require variables PROJROOT, CPP, CFLAGS, CPPFLAGS" >&2; exit 1; }

{
	echo "#define INCLUDE_SDL";
	echo "#define INCLUDE_GL";
	echo "#include \"config.h\"";
	while read ConstName; do
			echo "#ifdef $ConstName";
			echo "validconst_$ConstName";
			echo "#endif";
	done;
} | ${CPP} ${CFLAGS} ${CPPFLAGS} - | grep validconst_ \
  | sed -e 's/validconst_\(.*\)$/\1/'

(
echo
echo "  ConstList.txt has been generated by taking my own machine's valid list of"
echo "  constants and running it through your preprocessor.  Hopefully it works"
echo "  for you.  If not, try grepping your GL header files for #define GL*, and"
echo "  put the name of every constant you'd like to have at runtime into the"
echo "  ConstList.txt file."
echo "  Note that CmdlineGL can only use integer constants, and not all GL_* are."
echo "  Also beware: 'make clean' will remove it!"
echo
) >&2