arc.pm

# -*- code: utf-8 -*-
package arc;
my($VERSION);
$VERSION = "2018-09-07 11:40" ; # written by emacs time-stamp

use POSIX qw(floor ceil);

sub arc($$$$ $$$$){
    my ($x)		= shift; # center coordinate x
    my ($y)		= shift; # center coordinate y
    my ($start_angle)	= shift; # in degree
    my ($end_angle)	= shift; # in degree

    my ($radius)	= shift; # in micron
    my ($polygon_count)	= shift; # default 12;
    my ($ROUND)		= shift; # round to this unit ( making not smooth line);
    my ($direction)	= shift; # -1  counter clockwise, 1 clockwise

    if ($polygon_count eq '') { $polygon_count = 12;}

    my (@PTR);
    if ($end_angle < $start_angle  && $direction > 0) { $end_angle += 360;}
    if ($end_angle == 0 && $start_angle == 0 ) { $start_angle = 0; $end_angle = 360;}

    my ($step)		= 
    ($end_angle - $start_angle)/$polygon_count;
    my ($count)		= ceil((abs($end_angle - $start_angle))/$step);
    my ($prevX, $prevY);
    foreach my $i (0 .. $count ){
	my $radian = ($start_angle + $i * $step) * 3.1415926535/180;
	my ($X) = $x + $radius * cos($radian);
	my ($Y) = $y + $radius * sin($radian);
	push(@PTR, [ $X, $Y]);
    }
    if ($direction < 0 ){ @PTR = reverse @PTR ;}
    my @COORDS;
    foreach my $i (0 .. $count){    
	push(@COORDS, ($PTR[$i]->[0],
	               $PTR[$i]->[1] ) );
    }
#    print join ("\n", @COORDS). "\n";
    return @COORDS
}
1;