#!/usr/local/bin/perl

# This PERL script takes a file that was saved by xfig 3.1 and creates
# ASCII output that lists the polygons in a way that is easy to parse.

# AUTHOR:  Steven M. LaValle
#          Computer Science Department
#          Stanford University
# DATE:    18 January 1997

# DESCRIPTION: This tool was developed to help students generate motion
# planning examples easily in CS326A, Motion Planning.  The objects that
# are drawn must be color coded.  Each color identifies a type, such as
# "OBSTACLE" or "ROBOT1".  These names and colors can be easily modified 
# below.  Some objects can be translated to make their centroid be the
# origin (which is useful for a robot).  These translatable objects
# are listed below in the variable @movables.
#
# Perform these steps to use this script: 
#
#   1. Use xfig to generate a figure using polygon and rectangle functions.
#   2. Click on "Edit" to change each polygon "Fill color" to one listed 
#      below.  You can optionally change the "Fill style" to "Filled" to
#      prevent confusion amongst different types of polygons.
#   3. Save the resulting file in the <name>.fig format.
#   4. Run this script from UNIX as: xfig2mp <name>.fig > output
#      If UNIX says "Permission denied", first enter: chmod 755 xfig2mp
#
# You can alternatively change the fill style and color while drawing
# the polygons or rectangles, but be warned that this could cause xfig 
# to crash on some SGI systems (because xfig doesn't realize that it can
# use 24-bit color).

# Change the correspondences here to make new types with corresponding
# colors.  The keys in %types are color indices that appear in the xfig
# file.
# Here are some color codes: 0 = Black, 1 = Blue, 2 = Green, 4 = Red, 
#                            6 = Yellow, 7 = White
#
#    5 = Magenta
#    3 = Cyan
#    8 = Blue4
#
# You can find other codes by changing object colors and doing a "diff"
# on the two files.

%types = (0,"OBSTACLES",
          1,"ROBOT1",
          2,"ROBOT2",
          4,"ROBOT3",
          7,"BORDER",
          6,"GOAL",
	  5,"PATH1",
	  3,"PATH2",
	  8,"PATH3");

# Place any object name below that you would like to have translated to 
# have its centroid be the origin.

@movables = ("ROBOT1", "ROBOT2", "ROBOT3");


%polys = ();

# Read each line of the file, grabbing rectangles and polygons

@text = <>;

$index = 5;

while ($index <= $#text) {
   if (@text[$index] =~ /^2 2|^2 3|^2 1/)
      # If the line represents a polygon or rectangle
      {
         @text[$index] =~ /^2 \d \S+ \S+ \S+ (\d+)/;  
             # $1 will now contain the color index
         $index++;
             # Grab all of the points
         while ( !(@text[$index] =~ /^\d \d/) && 
                 ($index <= $#text)) {
             # Concatenate the points based on color
             $polys{ $1 } .= @text[$index];
             $index++;
	 }
      }
   else
      {
         $index++;
      }
}


foreach $key (keys %types) {
   if ($polys{$key}) {
      print $types{$key},"\n";     # Print the polygon type
      @pts = &STRINGTONUMBERS($polys{$key}); # Convert string to array
      if (grep($types{$key} eq $_, @movables)) { # Check to translate it
         @pts = &CENTER_POLYGONS(@pts);
      }
      $index = 0;
      while ($index < $#pts) {
         $firstx = @pts[$index]; $firsty = @pts[$index + 1];
         @polygon = ($firstx,$firsty);
         $index += 2;
         while ((($firstx != @pts[$index]) ||
                 ($firsty != @pts[$index + 1])) &&
                ($index <= $#pts))
	 {
            push(@polygon,@pts[$index]);
            push(@polygon,@pts[$index + 1]);
            $index += 2;
         }
         print(($#polygon + 1)/2,"\n");  # Print number of points in polygon
         for ($i = 0; $i < $#polygon; $i = $i+2) { 
             # Print each point
             print @polygon[$i]/100," ",@polygon[$i+1]/100,"\n"; 
         }  
         $index += 2;
      }   
      print "\n\n";
   }
}




# This routine converts the concatenated strings containing integers into an
# array of integers.
sub STRINGTONUMBERS {
   local($string)=@_;
   local(@nums)=();
   $numbers_left = ($string =~ /(\d+\b)/);
   while ($numbers_left) {
      push(@nums,$1);
      $string = substr($string,index($string,$1)+length($1));
      $numbers_left = ($string =~ / (\d+)/);
   }
   @nums;
}




# This routine translates the polygon so that its centroid is the origin.
# Note this is the centroid of the vertices, not the area centroid.
sub CENTER_POLYGONS {
   local($pts)=@_;
   local(@newpts)=();
   local($xmean)=0.0;
   local($ymean)=0.0;
   for ($i = 0; $i < $#pts; $i = $i+2) { 
      $xmean += @pts[$i];
      $ymean += @pts[$i + 1];
   }
   $xmean = $xmean * 2 / ($#pts+1);
   $ymean = $ymean * 2 / ($#pts+1);
   for ($i = 0; $i < $#pts; $i = $i+2) { 
      push(@newpts,@pts[$i] - $xmean);
      push(@newpts,@pts[$i + 1] - $ymean);
   }
   @newpts;
}