#!/bin/sh
# Copyright © 2018 Jamie Zawinski <jwz@jwz.org>
#
# Permission to use, copy, modify, distribute, and sell this software and its
# documentation for any purpose is hereby granted without fee, provided that
# the above copyright notice appear in all copies and that both that
# copyright notice and this permission notice appear in supporting
# documentation.  No representations are made about the suitability of this
# software for any purpose.  It is provided "as is" without express or 
# implied warranty.
#
# Converts a binary file to a C source code string, e.g., to embed the
# contents of a PNG file by including a .h file.
#
# Created:  7-Feb-2018.

usage () {
  echo "usage: $0 in.png out_png.h" >&2
  exit 1
}

if [ $# != 2 ]; then usage; fi

IN="$1"
OUT="$2"

NAME=`echo "$OUT" | sed \
  -e 's@^.*/@@' \
  -e 's/\.[^.]*$//' \
  -e 's/[-.]/_/g' \
  -e 's/^\([^a-z]\)/_\1/'`;

if [ x"$PERL" = "x" ]; then PERL=perl ; fi

# On Linux, we could do this and put the raw image into a .o data segment:
#	$(LD) -r -b binary $< -o $@
# but that doesn't work on MacOS.

exec $PERL -0 -pe "
  BEGIN { print \"#ifdef __GNUC__\\n\";
	  print \"__extension__\\n\";
	  print \"#endif\\n\";
	  print \"static const unsigned char ${NAME}[] =\\n \\\"\"; }
  END   { print \"\\\";\\n\"; }
  s/([^ -\041\043-\076\100-\133\135-\176])/sprintf(\"\\\\%03o\",ord(\$1))/gse;"\
  < "$IN" > "$OUT"