# Purpose: Conversion of plot data sets to fig format
# Author:  Lukas Knecht
# Created:  3 Apr 1998
#
FigPlot := proc(objs: list(structure), dim: [real, real])
  description
  'Convert a plot data set to fig format on stdout. dim is the dimension of
  the output rectangle in inches and defaults to portrait A4 (7.77" x 11.19")';
  printf('#FIG 3.1\nPortrait\nCenter\nMetric\n1200 2\n');
  
  FindColor := proc(colors: [list], color: [real, real, real])
    for i to length(colors[1]) while
    colors[1,i] = 0 or (colors[1,i] - color) * (colors[1,i] - color) > 0.01 do
    od;
    if i > length(colors[1]) then
      colors[1] := append(colors[1], color)
    fi;
    i - 1
  end:
  
  # Determine extent of all objects and construct color pseudo objects
  colors := CreateArray(1..32); # predefined colors
  i := 0;
  for r from 0 to 1 do for g from 0 to 1 do for b from 0 to 1 do
    i := i + 1; colors[i] := [r, g, b]
  od od od;
  colors := [colors]; # to pass by reference
  minx := miny := DBL_MAX; maxx := maxy := -DBL_MAX;
  for o in objs do
    for i to length(o) by 2 while type(o[i], real) and type(o[i+1], real) do
      minx := min(minx, o[i]); maxx := max(maxx, o[i]);
      miny := min(miny, o[i+1]); maxy := max(maxy, o[i+1])
    od;
    for i from i to length(o) do
      if type(o[i], equation) and op(1,o[i]) = 'color' then
	FindColor(colors, op(2,o[i]))
      fi
    od
  od;
  # Output color objects
  for i from 33 to length(colors[1]) do
    printf('0 %d #%02x%02x%02x\n', i - 1,
	   255*colors[1,i,1], 255*colors[1,i,2], 255*colors[1,i,3])
  od;
  # Compute the scale such that the entire figure fits into the output rectangle
  if nargs > 1 then size := dim else size := [7.77, 11.19] fi;
  scale := 1200 * min(size[1] / (maxx - minx), size[2] / (maxy - miny));
  # Output the graphical objects
  for o in objs do
    # Get the options
    color := 0; fill := -1; pts := 10; width := 2; angle := 0;
    for i to length(o) do
      if type(o[i], equation) then
	if op(1,o[i]) = 'color' then color := FindColor(colors, op(2,o[i]))
	elif op(1,o[i]) = 'fill' then fill := 40 - 20 * op(2,o[i])
	elif op(1,o[i]) = 'points' then pts := op(2,o[i])
	elif op(1,o[i]) = 'width' then width := 1200 / 72 * op(2,o[i])
	elif op(1,o[i]) = 'angle' then angle := Pi / 180 * op(2,o[i])
	fi
      fi
    od;
    if op(0,o) = 'LINE' then
      printf('2 1 0 %d %d %d 0 0 -1 0.000 0 0 -1 0 0 2\n\t',
	     width, color, color);
      printf('%d %d %d %d\n',
	     scale * (o[1] - minx), scale * (maxy - o[2]),
	     scale * (o[3] - minx), scale * (maxy - o[4]))
    elif op(0,o) = 'POLYGON' then
      for n to length(o) by 2 while type(o[n], real) and type(o[n+1], real) do
      od;
      n := (n - 1) / 2;
      printf('2 3 0 %d %d %d 0 0 %d 0.000 0 0 -1 0 0 %d\n\t',
	     width, color, color, fill, n + 1);
      for i to n do
	printf('%d %d ', scale * (o[2*i-1] - minx), scale * (maxy - o[2*i]))
      od;
      printf('%d %d\n', scale * (o[1] - minx), scale * (maxy - o[2]))
    elif op(0,o) = 'CIRCLE' then
      x := scale * (o[1] - minx); y := scale * (maxy - o[2]);
      r := 1200 / 72 * o[3];
      printf('1 3 0 %d %d %d 0 0 %d 0.000 1 0.000 %d %d %d %d %d %d %d %d\n',
	     width, color, color, fill, x, y, r, r, x, y, x + r, y)
    elif op(0,o) = 'LTEXT' or op(0,o) = 'CTEXT' or op(0,o) = 'RTEXT' then
      printf('4 ');
      if op(0,o) = 'LTEXT' then printf('0')
      elif op(0,o) = 'CTEXT' then printf('1')
      else printf('2') fi;
      printf(' %d 0 -1 16 %d %.3f 4 %d %d %d %d %s\\001\n',
	     color, pts, angle,
	     pts * 1200 / 72, length(o[3]) * 0.5 * pts * 1200 / 72,
	     scale * (o[1] - minx), scale * (maxy - o[2]), o[3]);
    else error('Cannot convert', o) fi
  od
end:

GifPlot := proc(objs: list(structure), giffile: string, dim: [posint, posint])
  description
  'Convert a plot data set to a gif file. dim is the dimension of the
  resulting pixmap.';
  tmpfile := '/tmp/'.getpid();
  Set(plotoutput=tmpfile.'.ps');
  Set(plotdevice=psportrait);
  DrawPlot(objs, proportional);
  CallSystem(sprintf('sed ''s/36 36 translate/0 0 translate/'' %s.ps | gs -q -dBATCH -dNOPAUSE -dSAFER -sDEVICE=ppmraw -r%d -g%dx%d -sOutputFile=%s.ppm - && ppmquant 256 %s.ppm 2> /dev/null | ppmtogif > %s 2> /dev/null; rm %s.*',
		     tmpfile, max(dim[1] / 7, dim[2] / 10.5), dim[1], dim[2],
		     tmpfile, tmpfile, giffile, tmpfile));
  NULL
end: