inscribe_polygon.pm

#!/usr/pkg/bin/perl
package inscribe;
use GDS2;
use strict;

#require './text2gds.pm';
require './arc.pm';
my %DUPE_CHECK;
# -----------------------------------------------------
#          generate structure circle
# -----------------------------------------------------
sub circle ($$$){
    my $radius = shift;
    my $polygon_count = shift;
    my $gds2File = shift;

    my $name = sprintf("circle-R%1.2f", $radius);
    if ($DUPE_CHECK{$name}++) { return $name;}
    $gds2File -> printBgnstr(-name => $name);
    $gds2File -> printBoundary (
	-xy => [arc::arc (0, 0, 0, 360, $radius, $polygon_count, ' ', 1)],
        -layer => 56 );
    $gds2File -> printEndstr();
    return $name;
}
# -----------------------------------------------------
#   calculate the coordinate on the circle from x or y
# ----------------------------------------------------
sub get_other($$) {
    my $x = shift;
    my $radius = shift;

    my $y = sqrt( abs( $radius * $radius - $x * $x));
    return $y;
}
# -----------------------------------------------------
#    M A I N   S U B R O U T I N E
# -----------------------------------------------------
sub inscribe_polygon($$$) {
  my $size     = shift;    # size of circle  (to inscribe)
  my $pitch    = shift;    # segment length
  my $gds2File = shift;

 my $structure_name = sprintf("inscribe_polygon-S%1.2f-P%1.2f", $size, $pitch);

# -------------------------------------
#       make reference cirlce
# -------------------------------------
my $polygon_count = int($size * 8);
if ($polygon_count < 72) { $polygon_count = 72;}
my $circle_name = circle( $size/2, $polygon_count, $gds2File);
# -------------------------------------


my $radius = $size  /2;
my $ratio = 0.99; # start point ratio, set 1 makes the length of first segment equals to 0
# take care the case if the pitch is very small against the circle
  if ($radius * ( 1 - $ratio) > $pitch/2) { $ratio = ($radius - $pitch/2)/$radius ; }
  
my $start_to_divide  = $radius * $ratio;
my $end_to_divide    = $radius * sqrt(2)/2;

my $pre_count = int($radius/$pitch);  # from whole size
my $quadrant_count =  int(($pre_count - 2)/ 2);  # half after two extreme removed
  if ($quadrant_count == 0 ) { $quadrant_count = 1;}
my $step = (- $end_to_divide + $start_to_divide) / $quadrant_count;

  printf("%04d pre count/partial count/step: %4d / %4d / %4.3f\n", __LINE__, $pre_count, $quadrant_count, $step);

my @part_pointer;	#  for  0 .. 45 degree, on the circle line
my @rev_pointer;	#  for 45 .. 90 degree, on the circle line

my @pointer;		#  for  0 .. 90 

my $index = 0;		# only for debug, not used for now

my $X = 0;		# constant Macro
my $Y = 1;		# ditto

my @COORDS_PTR;		# coordinate pointer, x1, y1, x2, y2, ... xn, yn
  			# add the coordinate inside of the circle (in between)

# ------------------------------------------------------
#            from 0 to 45 degree
# ------------------------------------------------------

foreach my $i ( 0.. $quadrant_count -1) {
#    print __LINE__ .' * ' . $index++. "\n";
    my ($this_x, $this_y);
    $this_x = $start_to_divide - $i * $step	  ;  # decreasing at 1st quadrant
    $this_y = get_other($this_x, $radius);
    push(@part_pointer, [$this_x, $this_y]);
# ----------------------------------------
    push(@COORDS_PTR,   [$this_x,                     $this_y]);
    push(@COORDS_PTR,   [$this_x - $step,             $this_y]);
# ----------------------------------------
}
my $E = $end_to_divide;

push(@pointer, @part_pointer);		# copy the first 0 .. 45 to whole

push(@pointer, [$E, $E]);		# put the center point
push(@COORDS_PTR, [$E, $E]);		# also add on actual coordinate.

# -------------------------------------------------------------------
#     from 45 to 90 degree,  copy 0 .. 45 data with reversed order
# -------------------------------------------------------------------

foreach my $i (reverse (0 .. $#part_pointer)) {
#    print __LINE__ .' * ' . $index++. "\n";
    push (@rev_pointer, [$part_pointer[$i] ->[$Y],
			 $part_pointer[$i] ->[$X]]);
# ----------------------------------------
    push(@COORDS_PTR,   [$part_pointer[$i] ->[$Y],
			 $part_pointer[$i] ->[$X] - $step]);
    push(@COORDS_PTR,   [$part_pointer[$i] ->[$Y],
			 $part_pointer[$i] ->[$X]]);
# ----------------------------------------
}
push(@pointer, @rev_pointer);		# copy the 45 .. 90 to whole


# ------------------------------
#       start real structure 
# ------------------------------

$gds2File -> printBgnstr(-name => $structure_name);
  if (0) {
for my $i ( 0..$#pointer){
    text2gds::text_flat( $pointer[$i] -> [$X], $pointer[$i] -> [$Y],
			15, $pitch/30, $i + 1, $gds2File); 
}
  }

my @COORDS;		# This will finally be the printBoundary coordinates.
# ------------------------------
#       pointer to vertex, one quadrant by one quadrant
# ------------------------------

for my $i ( 0..$#COORDS_PTR){
    push (@COORDS,         $COORDS_PTR[$i] -> [$X],
	                   $COORDS_PTR[$i] -> [$Y]);}
for my $i ( reverse 0..$#COORDS_PTR){
    push (@COORDS,       - $COORDS_PTR[$i] -> [$X],
	                   $COORDS_PTR[$i] -> [$Y]);}
for my $i ( 0..$#COORDS_PTR){
    push (@COORDS,       - $COORDS_PTR[$i] -> [$X],
	                 - $COORDS_PTR[$i] -> [$Y]);}
for my $i ( reverse 0..$#COORDS_PTR){
    push (@COORDS,         $COORDS_PTR[$i] -> [$X],
	                 - $COORDS_PTR[$i] -> [$Y]);}

$gds2File -> printBoundary  (-xy=> [@COORDS], -layer=> 0);

# place reference circle
    $gds2File -> printSref(
	-name => $circle_name,
	-xy => [0, 0]);
$gds2File -> printEndstr();
return $structure_name;
}
1;
__END__