############################################################################
#
#	File:     giftoims.icn
#
#	Subject:  Program to convert GIF files to image strings
#
#	Author:   Ralph E. Griswold
#
#	Date:     June 10, 2001
#
############################################################################
#
#   This file is in the public domain.
#
############################################################################
#
#  This program converts GIF images whose names are given on the command
#  line to image strings as used by DrawImage().
#
#  The image strings are written to files with the basenames of the GIF
#  files and the suffix "ims" or "iml" depending on the output option.
#
#  The following options are supported:
#
#	-l	write Icon literal instead of plain string; suffix is
#		  .iml (default .ims).
#	-i i	make lines of literals at most i characters long
#	-p s	palette to use; default c1.
#
#  For -l, the length refers to the number of characters represented.  If
#  they require escapes, thea actual line length will be longer.  This is
#  to prevent errors from trying to continue a string literal in the
#  middle of an escape sequence.  In addition, three blanks are prepended
#  to each line and the characters # and $ are escaped to prevent then
#  from being misinterpreted by Icon's translator.
#
#  .iml files are suitable for inclusion in program text, either
#  directly or by $include.
#
#  .ims files are suitable for reading.
#
############################################################################
#
#  Requires:  Version 9 graphics
#
############################################################################
#
#  Links:  basename, graphics, options, strings
#
############################################################################

link basename
link graphics
link options
link strings

procedure main(args)
   local file, opts, name, output, literal, length, seg, palette, str
   local suffix

   opts := options(args, "i+lp:")

   literal := opts["l"]
   length := opts["i"]
   palette := \opts["p"] | "c1"

   suffix := if \literal then ".iml" else ".ims"

   if not PaletteChars(palette) then
      stop("*** invalid palette specification")

   every file := !args do {
      name := basename(file, ".gif") || suffix
      WOpen("canvas=hidden", "image=" || file) | {
         write(&errout, "**** can't open ", file)
         next
         }
      output := open(name, "w") | {
         write(&errout, "*** can't write to ", name)
         next
         }
      str := Capture(palette)
      if /literal then writes(output, str)
      else {
         if  /length then str ? {
         length := integer(tab(upto(',')))
         }
         str ? {
            write(output, "   \"", tab(upto(',') + 1), tab(upto(',') + 1), "_")
            while seg := move(length) do {
               if pos(0) then write(output, "   ", esc(seg), "\"")
               else write(output, "   ", esc(seg), "_")
               }
            if not pos(0) then write(output, "   ", esc(tab(0)), "\"")
            }
         }
      close(output)
      WClose()
      }

end

procedure esc(s)

   s := image(s)
   s := replace(s, "$", "\\x24")
   s := replace(s, "#", "\\x23")

   return s[2:-1]

end