use warnings;
use List::Util qw( min max );
-our $VERSION = '1.02';
+our $VERSION = '1.03';
# ITU-R recommendation 601 luma co-efficients
our $kr = .299;
}
sub hue {
+ # colour shift (red = 0 .. 1)
my ($r, $g, $b) = @{ $_[0] };
my $hue = atan2 sqrt(3) * ($g - $b), $r*2 - $g - $b;
- return ($hue + $PI) / $PI / 2; # 0 .. 1
+ $hue /= $PI * 2; # -.5 .. .5
+ $hue++ if $hue < 0; # fp $hue %= 1
+ return $hue;
}
sub rgb24 {
<div class="section">
<:
-use Shiar_Sheet::Colour '1.02';
+use Shiar_Sheet::Colour '1.03';
use List::Util qw( min max );
sub colcell {
my $index = $r*6*6 + $g*6 + $b + 16;
my @rgb = map { $_ && $_*40 + 55 } $r, $g, $b;
- my $h = Shiar_Sheet::Colour->new(@rgb)->hue * 35;
+ my $h = Shiar_Sheet::Colour->new(@rgb)->hue * 33;
my $v = int(max(@rgb) / 255 * 5);
my $s = abs(min(@rgb) - max(@rgb)) / 255 * 7;
my $grey = !$s;
- $h-- for grep {$h >= $_} 4, 6, 16, 19, 28, 31;
$v = 5 - $v;
$s = 7 - $s - $v;
$s-- if $s;
if ($grey) {
- $h = 30; # greyscale hue
+ $h = 33; # greyscale hue
$s -= 2; # lowest saturation for other hues
$v = $s = 0 if $s < 0; # black at full saturation
}
{
print '<table class=mapped>';
printf '<colgroup span=%d>', 3 * @{$_} for @colmap;
- for my $h (0 .. 30) {
+ for my $h (grep { $colmap[0][0][$_] } 0 .. $#{ $colmap[0][0] }) {
print '<tr>';
print colcell(@$_) for map { $_->[$h] } map { @{$_} } @colmap;
}