############################################################################
#
#	File:     xformpat.icn
#
#	Subject:  Program to apply transformation to patterns
#
#	Author:   Ralph E. Griswold
#
#	Date:     August 12, 1993
#
############################################################################
#
#   This file is in the public domain.
#
############################################################################
#
#  This program takes patterns from standard input and applies a
#  transformation to each one, writing the results to standard output.
#  The transformation to be applied is given in terms of command-line
#  arguments, with the transformation first, followed by any arguments,
#  as in
#
#	xformpat center 32 32
#
#  which would attempt to produce a 32x32 centered pattern from each
#  pattern in standard input.
#
#  Warning:  Some transformations can fail.  In cae of failure, no
#  pattern is written.
#
############################################################################
#
#  Links:  patxform
#
############################################################################

invocable all

link patxform

procedure main(args)
   local xform, rows

   xform := proc("p" || args[1]) | stop("** invalid transformation")

   while rows := pat2rows(readpatt()) do {
      get(args)			# a trick here; there's always an extra
      push(args, rows)
      write(rows2pat(xform ! args))
      }

end