X-Git-Url: http://git.shiar.nl/sheet.git/blobdiff_plain/b7db12d1360aaf34f69ce856cc2bab385f68080e..83596eca2ea1782932a4af42727ece9af8067f13:/Shiar_Sheet/Colour.pm

diff --git a/Shiar_Sheet/Colour.pm b/Shiar_Sheet/Colour.pm
new file mode 100644
index 0000000..1812789
--- /dev/null
+++ b/Shiar_Sheet/Colour.pm
@@ -0,0 +1,34 @@
+package Shiar_Sheet::Colour;
+
+use strict;
+use warnings;
+use List::Util 'min';
+
+our $VERSION = '1.00';
+
+sub new {
+	my $class = shift;
+	my @rgb = @_ >= 3 ? @_ : (map {hex} $_[0] =~ /(..)/g);
+	bless \@rgb, $class;
+}
+
+sub luminance {
+	# perceived brightness (using ITU-R recommendation 601 luma co-efficients)
+	my ($r, $g, $b) = @{ $_[0] };
+	return $r*.299 + $g*.587 + $b*.114;
+}
+
+sub rgb24 {
+	my $str = '';
+	$str .= sprintf '%X', min($_ / 17 + .5, 15) for @{ $_[0] };
+	return $str;
+}
+
+sub rgb48 {
+	my $str = '';
+	$str .= sprintf '%02X', $_ for @{ $_[0] };
+	return $str;
+}
+
+1;
+