#!/usr/bin/perl -w
use strict;
use lib '.';
use common;

sub pi() { 4 * atan2(1, 1) }

print "<style> div { float: left; width: 40px; height: 40px; margin: 1em; overflow: hidden; } body { background: black; } hr { clear: both; }</style>";

my $c = {
    'red' => 0,
    'green' => 0,
    'blue' => 0,
    'low' => 0,
};
convertsRGBtoHCY($c);

my @forceColours = ( {
    'red' => 0,
    'green' => 0,
    'blue' => 0,
}, {
    'red' => 255,
    'green' => 0,
    'blue' => 0,
}, {
    'red' => 0,
    'green' => 255,
    'blue' => 0,
}, {
    'red' => 0,
    'green' => 0,
    'blue' => 255,
}, {
    'red' => 255,
    'green' => 255,
    'blue' => 0,
}, {
    'red' => 0,
    'green' => 255,
    'blue' => 255,
}, {
    'red' => 255,
    'green' => 0,
    'blue' => 255,
}, {
    'red' => 255,
    'green' => 128,
    'blue' => 0,
}, {
    'red' => 128,
    'green' => 128,
    'blue' => 128,
}, {
    'red' => 32,
    'green' => 32,
    'blue' => 32,
}, {
    'red' => 172,
    'green' => 172,
    'blue' => 172,
}, {
    'red' => 172,
    'green' => 173,
    'blue' => 172,
}, {
    'red' => 254,
    'green' => 255,
    'blue' => 255,
}, {
    'red' => 255,
    'green' => 255,
    'blue' => 255,
}, {
    'red' => 161,
    'green' => 195,
    'blue' => 41,
});

my @colours = ($c);
my $maxH = 360;
my $reqDH = 30;
my $reqDRGB = 125;
my $attempts = 0;
colour: while (@colours < 200) {
    $attempts += 1;
    last colour if $attempts > 1000;
    my $forced;
    if (@forceColours) {
        $c = pop @forceColours;
        $forced = 1;
    } else {
        $c = {
            'red' => randcomp(),
            'green' => randcomp(),
            'blue' => randcomp(),
        };
        $forced = 0;
    }
    convertsRGBtoHCY($c);
    warn sprintf "\ntrying %d,%d,%d %s  H=%d, C=%d, Y'=%d\n", $c->{red}, $c->{green}, $c->{blue}, $forced ? 'forced' : '', $c->{H}, $c->{C}, $c->{"Y'"};
    my $low;
    foreach (@colours) {
        warn sprintf "against %d,%d,%d %s  H=%d, C=%d, Y'=%d\n", $_->{red}, $_->{green}, $_->{blue}, '', $_->{H}, $_->{C}, $_->{"Y'"};
        my $DRGB = abs($c->{red}-$_->{red}) + abs($c->{green}-$_->{green}) + abs($c->{blue}-$_->{blue});
        my $DH = abs($_->{H}-$c->{H});
        my $DC = abs($_->{C}-$c->{C});
        my $MC = ($_->{C}+$c->{C})/2;
        if ($DH > $maxH/2) {
            $DH = $maxH - $DH;
        }
        my $DY = abs($_->{"Y'"}-$c->{"Y'"});
        my $MY = ($_->{"Y'"}+$c->{"Y'"})/2;
        warn "DRGB=$DRGB; DH=$DH; DC=$DC; DY=$DY; MC=$MC; MY=$MY\n";
        if ($DRGB < $reqDRGB) {
            warn sprintf "losing forced colour %d,%d,%d because DRGB is only $DRGB\n", $c->{red}, $c->{green}, $c->{blue} if $forced;
            next colour;
        }
        if ($DY < 50 and $DC < 50) {
            #$DH *= abs(128-$MY)/128 * $MC/255;
            if ($DH < $reqDH) {
                warn sprintf "losing forced colour %d,%d,%d with DH=$DH\n", $c->{red}, $c->{green}, $c->{blue} if $forced;
                next colour;
            }
        } else {
            warn "good enough DY or DC\n";
            $DH = 999;
        }
        if (not defined $low or $low > $DH) {
            $low = $DH;
        }
    }
    $c->{low} = $low;
    push(@colours, $c);
    warn "keeping forced colour\n" if $forced;
    $attempts = 0;
}

foreach (@colours) {
    printf "<div style='background:rgb(%d, %d, %d)'>%f %f</div>\n", $_->{red}, $_->{green}, $_->{blue}, 0, $_->{low};
}
print '<hr>';
foreach (sort { $a->{'H'} <=> $b->{'H'} } @colours) {
    printf "<div style='background:rgb(%d, %d, %d)'>%f %f</div>\n", $_->{red}, $_->{green}, $_->{blue}, $_->{'H'}, $_->{low};
}
print '<hr>';
foreach (sort { $a->{"Y'"} <=> $b->{"Y'"} } @colours) {
    printf "<div style='background:rgb(%d, %d, %d)'>%f %f</div>\n", $_->{red}, $_->{green}, $_->{blue}, $_->{"Y'"}, $_->{low};
}

sub randcomp {
    return (cos(pi*rand(1))+1)*128;
}

sub convertsRGBtoHCY {
    my($c) = @_;
    my $r = $c->{red};
    my $g = $c->{green};
    my $b = $c->{blue};
    my $alpha = (1/2) * (2*$r-$g-$b);
    my $beta = (sqrt(3)/2) * ($g-$b);
    my $H = atan2($beta, $alpha);
    $H += 2*pi if ($H < 0);
    $H *= 180/pi;
#    if ($H > 100) {
 #       if ($H > 140) {
  #          $H -= 40;
   #     } else {
    #        $H = 100;
     #   }
    #}
    $c->{H} = $H;
    $c->{C} = sqrt($alpha**2+$beta**2);
    # Luma (Y') with sRGB (Rec. 709) primaries:
    # http://en.wikipedia.org/wiki/HSL_and_HSV#Lightness
    $c->{"Y'"} = 0.21*$r + 0.72*$g + 0.07*$b;
}