## Copyright (C) 1996, 1997 John W. Eaton
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2, or (at your option)
## any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, 59 Temple Place - Suite 330, Boston, MA
## 02111-1307, USA.

## Set the current colormap.
##
## colormap (map) sets the current colormap to map.  map should be an n
## row by 3 column matrix. The columns contain red, green, and blue
## intensities respectively.  All entries should be between 0 and 1
## inclusive. The new colormap is returned.
##
## colormap ("default") restores the default colormap (a gray scale
## colormap with 64 entries). The default colormap is returned.
##
## colormap with no arguments returns the current colormap.

## Author: Tony Richardson <arichard@stark.cc.oh.us>
## Created: July 1994
## Adapted-By: jwe

function cmap = colormap (map)

  global __current_color_map__ = gray ();

  if (nargin > 1)
    usage ("colormap (map)");
  endif

  if (nargin == 1)

    if (isstr (map))
      if (strcmp (map, "default"))
        map = gray ();
      else
	unwind_protect
	  save_default_eval_print_flag = default_eval_print_flag;
	  default_eval_print_flag = 0;
	  map = eval (map);
	unwind_protect_cleanup
	  default_eval_print_flag = save_default_eval_print_flag;
	end_unwind_protect
      endif
    endif

    if (! isempty (map))
      if (columns (map) != 3)
	error( "colormap: map must have 3 columns: [R,G,B]." );
      endif
      if (min (min (map)) < 0 || max (max (map)) > 1)
        error( "colormap: map must have values in [0,1]." );
      endif
      ## Set the new color map
      __current_color_map__ = map;
    endif

  endif

  ## Return current color map.
  cmap = __current_color_map__;

endfunction
