-<section>
-<h2>256-colour space</h2>
-<:
-for my $r (0 .. 5) {
- print '<table>';
- for my $g (0 .. 5) {
- print '<tr>';
- for my $b (0 .. 5) {
- my $index = $r*6*6 + $g*6 + $b + 16;
- print colcell($index, map { $_ && $_*40 + 55 } $r, $g, $b);
+ my %greymap; # name => value
+ my @colmap; # saturation => value => hue => [name, r,g,b]
+ my $offset = 16 * ($dim > 3);
+
+ for my $r (0 .. $dim - 1) {
+ for my $g (0 .. $dim - 1) {
+ for my $b (0 .. $dim - 1) {
+ my @rgb = ($r, $g, $b);
+
+ my $h = Shiar_Sheet::Colour->new(@rgb)->hue * $hmax;
+ my $v = max(@rgb);
+ my $s = abs(min(@rgb) - max(@rgb));
+
+ if (!$s) {
+ if ($greyramp) {
+ my ($index, $l) = $rgbval->(@rgb);
+ $greymap{$index} = $l;
+ next;
+ }
+
+ $h = $hmax; # greyscale hue
+ $s = 1; # lowest saturation for other hues
+ $v = $s = $vmax if !$v; # black at full saturation
+ }
+
+ $v = $vmax - $v;
+ $s = $smax - $s - $v;
+
+ $colmap[$s][$v][$h] = [ $rgbval->(@rgb) ];
+ }
+ }
+ }
+
+ my $out = '';
+ $out .= sprintf '<colgroup span=%d>', scalar @{$_} for @colmap;
+ my $huerow = $colmap[0][0]; # first {$_} map { @{$_} } @colmap;
+ for my $h (grep { $huerow->[$_] } 0 .. $#{$huerow}) {
+ $out .= '<tr>';
+ $out .= colcell(@$_) for map { $_->[$h] } map { @{$_} } @colmap;
+ }
+
+ if ($greyramp) {
+ $offset += $dim ** 3;
+ $greymap{$offset++} = $_ for @{$greyramp};
+ }
+
+ if (%greymap) {
+ $out .= '<tbody>';
+ my $col = 0;
+ my $colbreak = scalar map { @$_ } @colmap; # same width as hue rows
+ for my $num (sort { $greymap{$a} <=> $greymap{$b} } keys %greymap) {
+ $out .= '<tr>' unless $col++ % $colbreak;
+ $out .= colcell($num, ($greymap{$num}) x 3);