1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
#!perl -w
# takes spot function and builds an ordered dither 8x8 matrix
use strict;
my $func = shift or die "Usage: $0 function [width height expandx expandy]\n";
my $width = shift || 8;
my $height = shift || 8;
my @spot;
use vars qw($x $y);
for $y (0..$height-1) {
for $x (0..$width-1) {
my $res = eval $func;
$spot[$x+$y*$width] = $res * $res;
}
}
my @sp;
@sp[sort { $spot[$a] <=> $spot[$b] } (0.. $#spot)] = 0..$#spot;
while (@sp) {
print " ",map(sprintf("%4d,", 4*$_), splice(@sp, 0, $width)),"\n";
}
sub min {
my (@data) = @_;
my $min = shift @data;
for (@data) {
$min = $_ if $_ < $min;
}
$min;
}
sub dist {
my ($x1, $y1) = @_;
return ($x1-$x)*($x1-$x) + ($y1-$y)*($y1-$y);
}
sub theta {
my ($x1, $y1) = @_;
return atan2($y1-$y, $x1-$x);
}
sub dt {
my ($x1, $y1) = @_;
dist($x1, $y1)+theta($x1,$y1)/20;
}
|
