+
+ print '<table>', "\n";
+ printf "<caption>%s</caption>\n", $caption;
+ for my $num (0 .. $#{$colours}) {
+ my ($rgb, $name) = split /:/, $colours->[$num], 3;
+ $name ||= $num;
+ $name = [ $name, ['#333'] ] if $term eq 'xkcd';
+ print '<tr>', colcell($name, $rgb);
+ }
+ print "</table>\n\n";
+ }
+}
+
+sub coltable_hsv {
+ my ($dim, $rgbval, $greyramp) = @_;
+
+ my $hmax = 2 * $dim * 3; # each face of the rgb cube
+ my $vmax = $dim - 1;
+ my $smax = $dim - 1;
+ $rgbval ||= sub { join('', @_), map { int $_ * 255 / $vmax } @_ };
+ $greyramp ||= [];
+
+ 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) {
+ my ($index, $l) = $rgbval->(@rgb);
+ $greymap{$index} = $l;
+ next;
+ }
+
+ $v = $vmax - $v;
+ $s = $smax - $s - $v;
+
+ $colmap[$s][$v][$h] = [ $rgbval->(@rgb) ];
+ }
+ }
+ }
+
+ my $out = '';
+ $out .= sprintf '<colgroup span=%d>', 3 * @{$_} 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;