INST transforms { TLIST # Reflect about X and Z axes
  1 0 0 0
  0 1 0 0
  0 0 1 0
  0 0 0 1

  1 0 0 0
  0 1 0 0
  0 0 -1 0
  0 0 0 1

  -1 0 0 0
  0 1 0 0
  0 0 1 0
  0 0 0 1

  -1 0 0 0
  0 1 0 0
  0 0 -1 0
  0 0 0 1

 } geom {
   LIST
   { INST transform # Semicircular ends of torus
	1 0 0 0
	0 1 0 0
	0 0 1 0
	4 0 0 1

     geom < pieces/linkA.bez
   }
   { INST transforms { TLIST # Joining pieces
	1 0 0 0
	0 1 0 0
	0 0 1 0
	-4 0 0 1

	1 0 0 0
	0 -1 0 0
	0 0 1 0
	-4 0 0 1

	1 0 0 0
	0 1 0 0
	0 0 1 0
	0 0 0 1

	1 0 0 0
	0 -1 0 0
	0 0 1 0
	0 0 0 1

   } geom { < pieces/linkB.bez }
  }
 }

# #! /bin/sh
# 
# case "$1" in
#     [0-9]*) ;;
#     *)
# 	echo "Usage:  mktorus   nholes  >torus.oogl
# Constructs an N-holed torus using Bezier patch pieces in the data directory.
# setenv GEOM_PATH  <OOGL-directory>/data  when displaying the resulting objects
# if you're not already in the data directory." >&2
# 	exit 1
# 	;;
# esac
# 
# awk '
#  BEGIN {
# 	n = '$1';
# 	xfmt = "\t1 0 0 0\n\t0 %g 0 0\n\t0 0 1 0\n\t%g 0 0 1\n\n";
# 	print "INST transforms { TLIST # Reflect about X and Z axes";
# 	print "  1 0 0 0\n  0 1 0 0\n  0 0 1 0\n  0 0 0 1\n";
# 	print "  1 0 0 0\n  0 1 0 0\n  0 0 -1 0\n  0 0 0 1\n";
# 	print "  -1 0 0 0\n  0 1 0 0\n  0 0 1 0\n  0 0 0 1\n";
# 	print "  -1 0 0 0\n  0 1 0 0\n  0 0 -1 0\n  0 0 0 1\n";
# 	print " } geom {";
# 	print "   LIST";
# 	print "   { INST transform # Semicircular ends of torus";
# 	printf xfmt, 1, 2*(n-1);
# 	print "     geom < pieces/linkA.bez";
# 	print "   }";
# 	if(n > 1) {
# 	    print "   { INST transforms { TLIST # Joining pieces"
# 	    for(i = 0; i < n-1; i++) {
# 		printf xfmt, 1, 4*i - 2*n + 2;
# 		printf xfmt, -1, 4*i - 2*n + 2;
# 	    }
# 	    print "   } geom { < pieces/linkB.bez }";
# 	    print "  }";
# 	}
# 	print " }";
# 	exit
#   }'