openSVG( 450, 450 );
openG( transform => 'translate(10,85) scale(1,-1)' );
openG( transform => 'scale(5)' );
foreach ( -15 .. 15 ) {
    hline( 0, 80, $_ );
}
foreach ( 0 .. 80 ) {
    vline( -15, 15, $_ );
}
path(
    d     => 'M -1 0 H 81',
    style => 'stroke: red; stroke-opacity: .25; stroke-width: .1'
);
graphline( 'black', 0.1, @scores );
graphline( 'green', 0.1, @bestblack );
graphline( 'red',   0.1, @bestwhite );
closeG();
closeG();
closeSVG();

sub path {
    openTAG( 'path', @_ );
    closeTAG();
}

sub openTAG {
    my $tag        = shift;
    my %attributes = @_;

    print "<$tag";
    foreach ( keys %attributes ) {
        print " $_=\"$attributes{$_}\"";
    }
}

sub closeTAG {
    my $s = shift;

    if ($s) {
        print "</$s>\n";
    }
    else {
        print "/>\n";
    }
}

sub openG {
    openTAG( 'g', @_ );
    print ">\n";
}

sub closeG {
    closeTAG('g');
}

sub openSVG {
    my $height = shift;
    my $width  = shift;

    print "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n";
    print "<!DOCTYPE svg  PUBLIC \"-//W3C//DTD SVG 1.0//EN\"\n";
    print "  \"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd\">\n";
    print
"<svg height=\"$height\" width=\"$width\" viewbox=\"0,0,$width,$height\">\n";
}

sub closeSVG {
    closeTAG('svg');
}

sub hline {
    my ( $x1, $x2, $y1, $color ) = @_;

    if ($color) {
        path( d => "M $x1,$y1 H $x2", style => "stroke: $color;" );
    }
    else {
        path( d => "M $x1,$y1 H $x2" );
    }
}

sub vline {
    my ( $y1, $y2, $x1, $color ) = @_;

    if ($color) {
        path( d => "M $x1,$y1 V $y2", style => "stroke: $color;" );
    }
    else {
        path( d => "M $x1,$y1 V $y2" );
    }
}

sub graphline {
    my $color  = shift;
    my $width  = shift;
    my @values = @_;
    my @list;
    my $y = 0;

    foreach (@values) {
        if ($_) {
            push ( @list, $y );
            push ( @list, $_ );
        }
        $y++;
    }
    openTAG(
        'polyline',
        points => join ( ',', @list ),
        style => "stroke: $color; stroke-width: $width; fill: none;",
    );
    closeTAG();
}