Thanks for the extension hossman++. This works pretty
good. Only problem is, I gave you a very suboptimal
algorithm. Ok for 40 x 80, too slow for 200 x 200.
The big kludge was adding 8 points in adjacent squares.
This isn't necessary. Instead calculate the x and y
distances separately. If a distance is greater than .5,
adjust it to 1  distance. If a point is .7 from a vpoint,
it is .3 from a corresponding vpoint in an adjacent square.
This means about 90% fewer vpoints to test against, so
this is many times faster.
So here's another version based on your changes with an
additional color option.
YuckFoo
#!/usr/bin/perl
use strict;
use GD;
my $ROWS = 200; # number of rows
my $COLS = 200; # number of columns
my $POINTS = 12; # number of Voronoi points
my $COLORS = 128; # number of colors
my $INNER = [255, 255, 0]; # inner color (red, green, blue)
my $OUTER = [ 0, 32, 0]; # outer color (red, green, blue)
my $xfact = 1 / $COLS;
my $yfact = 1 / $ROWS;
# Allocate some colors
my $img = new GD::Image($COLS, $ROWS);
my $colors = makecolors($img, $COLORS, $INNER, $OUTER);
my (@xs, @ys);
# Pick some random points
for (0..$POINTS1) {
push (@xs, rand());
push (@ys, rand());
}
# Calculate screen
for my $yi (0..$ROWS1) {
my $y = $yi * $yfact;
for my $xi (0..$COLS1) {
my $x = $xi * $xfact;
my ($best, $good) = closest($x, $y, \@xs, \@ys);
$img>setPixel($xi, $yi, $colors>[$COLORS * ($best / $good)]
+);
}
}
binmode STDOUT;
print $img>png();
#
sub closest {
my ($x, $y, $xs, $ys) = @_;
my ($dist, $best, $good);
for (my $i = 0; $i < @$xs; $i++) {
my $xdiff = abs($x  $xs>[$i]);
my $ydiff = abs($y  $ys>[$i]);
if ($xdiff > .5) { $xdiff = 1  $xdiff; }
if ($ydiff > .5) { $ydiff = 1  $ydiff; }
$dist = sqrt($xdiff * $xdiff + $ydiff * $ydiff);
if ($i == 0  $dist < $best) { ($good, $best) = ($best, $dis
+t); }
elsif ($i == 1  $dist < $good) { $good = $dist; }
}
return ($best, $good);
}
#
sub makecolors {
my ($img, $num, $beg, $end) = @_;
my (@colors);
my $red = ($end>[0]  $beg>[0]) / $num;
my $green = ($end>[1]  $beg>[1]) / $num;
my $blue = ($end>[2]  $beg>[2]) / $num;
for (my $i = 0; $i < $num; $i++) {
$beg>[0] += $red;
$beg>[1] += $green;
$beg>[2] += $blue;
push (@colors, $img>colorAllocate(@$beg));
}
return \@colors;
}
