X-Git-Url: http://git.shiar.nl/sheet.git/blobdiff_plain/1f3b44e51107dc97ce2bded07b93325e96835744..1b74f2fe18e42ec7acd07793fc45da6c0849fcc9:/Shiar_Sheet/Colour.pm

diff --git a/Shiar_Sheet/Colour.pm b/Shiar_Sheet/Colour.pm
index cedfdfb..e431cfe 100644
--- a/Shiar_Sheet/Colour.pm
+++ b/Shiar_Sheet/Colour.pm
@@ -4,7 +4,7 @@ use strict;
 use warnings;
 use List::Util qw( min max );
 
-our $VERSION = '1.02';
+our $VERSION = '1.05';
 
 # ITU-R recommendation 601 luma co-efficients
 our $kr = .299;
@@ -20,12 +20,9 @@ sub new {
 }
 
 sub newyuv {
-	# convert from YPbPr values 0..255 (or hex string)
+	# convert from YPbPr values -1..1
 	my $class = shift;
-	my ($y, $cb, $cr) = @_ >= 3 ? @_ : (map {hex} $_[0] =~ /(..)/g);
-
-	$_ -= 128 for $cb, $cr;
-	$_ /= 255 for $y, $cb, $cr;
+	my ($y, $cb, $cr) = @_;
 
 	my @rgb = map { max(0, min(255, $_ * 255)) } (
 		$y                             + $cr,
@@ -35,6 +32,17 @@ sub newyuv {
 	bless \@rgb, $class;
 }
 
+sub newyuv8 {
+	# 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;
+
+	$class->newyuv($y, $cb, $cr);
+}
+
 sub luminance {
 	# perceived brightness
 	my ($r, $g, $b) = @{ $_[0] };
@@ -42,9 +50,18 @@ sub luminance {
 }
 
 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 $hue;
+}
+
+sub hsv {
+	my ($rgb) = @_;
+	my $v = max(@{$rgb});
+	return $rgb->hue, abs(min(@{$rgb}) - $v), $v;
 }
 
 sub rgb24 {