From ddd5f9146c58ba38f16d2e525273b83076c4f93a Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Mon, 26 Oct 2015 13:08:04 +0100
Subject: [PATCH] termcol: 16-colour palettes for msx and c64

Additional data for common '90s home computers from Wikipedia
<https://en.wikipedia.org?oldid=686243993>,
with composite YPrPb values converted to hex and to RGB using formula from
<https://en.wikipedia.org?oldid=670394866#ITU-R_BT.601_conversion>.
---
 Shiar_Sheet/Colour.pm | 20 ++++++++++++++++++--
 termcol.plp           | 14 +++++++++++++-
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/Shiar_Sheet/Colour.pm b/Shiar_Sheet/Colour.pm
index 303e375..7ea68e9 100644
--- a/Shiar_Sheet/Colour.pm
+++ b/Shiar_Sheet/Colour.pm
@@ -2,9 +2,9 @@ package Shiar_Sheet::Colour;
 
 use strict;
 use warnings;
-use List::Util 'min';
+use List::Util qw( min max );
 
-our $VERSION = '1.00';
+our $VERSION = '1.01';
 
 # ITU-R recommendation 601 luma co-efficients
 our $kr = .299;
@@ -17,6 +17,22 @@ sub new {
 	bless \@rgb, $class;
 }
 
+sub newyuv {
+	# convert from YPbPr values 0..255 (or hex string)
+	my $class = shift;
+	my ($y, $cb, $cr) = @_ >= 3 ? @_ : (map {hex} $_[0] =~ /(..)/g);
+
+	$_ -= 128 for $cb, $cr;
+	$_ /= 255 for $y, $cb, $cr;
+
+	my @rgb = map { max(0, min(255, $_ * 255)) } (
+		$y                             + $cr,
+		$y - $cb * (1 - $kb) * $kb/$kg - $cr * $kr/$kg,
+		$y + $cb * (1 - $kb)           ,
+	);
+	bless \@rgb, $class;
+}
+
 sub luminance {
 	# perceived brightness
 	my ($r, $g, $b) = @{ $_[0] };
diff --git a/termcol.plp b/termcol.plp
index 0c51ab8..4b9f3e4 100644
--- a/termcol.plp
+++ b/termcol.plp
@@ -18,7 +18,7 @@ Html({
 
 <div class="section">
 <:
-use Shiar_Sheet::Colour;
+use Shiar_Sheet::Colour '1.01';
 
 sub colcell {
 	my $name = shift;
@@ -115,6 +115,18 @@ my %col = (
 		qw/FFFFFF DDDDDD BBBBBB 999999 777777 555555 333333 000000
 		   004499 EEEE00 00CC00 DD0000 EEEEBB 558800 FFBB00 00BBFF /,
 	],
+	c64 => [
+		'C=64',  # commodore 64/128
+		map { Shiar_Sheet::Colour->newyuv($_)->rgb48 }
+		qw/008080 FF8080 4F4FF5 9FB00A 5FDADA 7F2525 3FFF80 BF0080
+		   5F25DA 3F0AB0 7F4FF5 4F8080 778080 BF2525 77FF80 9F8080 /
+	],
+	msx => [
+		'MSX',
+		map { Shiar_Sheet::Colour->newyuv($_)->rgb48 }
+		qw/008080 008080 873F1F AA4F37 66FF6F 87EE76 7757D6 BAB70E
+		   874FEE AA4FEE BA1F98 CC3798 77462E 87B0BE CC8080 FF8080 /,
+	],
 );
 
 for my $term (qw/cga xterm tango app html xkcd/) {
-- 
2.30.0