#!/usr/bin/perl
## Author: Dan Jacobson https://www.jidanni.org/
## Copyright: https://www.gnu.org/licenses/gpl.html
## Created: 2026-02-17T23:09:20+0000
## Last-Updated: 2026-02-27T05:47:22+0000
##     Update #: 88

use strict;
use warnings FATAL => q(all);
my $Z = 1000;
my $V = qq{viewBox="0 0 $Z $Z"};
print qq{<svg $V xmlns="http://www.w3.org/2000/svg">\n};
## my @xmarks = (
##     "沿著馬路號碼增加方向 → ",
##     "Direction of increasing numbers as we travel along the road →"
## );
## for ( 60, 30 ) {    #X axis markings
##     printf
##       qq! <text x="%d" y="%d" font-size="%d" text-anchor="%s">%s</text>\n!,
##       coor( $Z / 2, $_ ), 28, "middle", shift @xmarks;
## }
for ( 0 .. ( $Z / 100 ) - 1 ) {    #Y axis markings
    printf
      qq! <text x="%d" y="%d" font-size="%d" text-anchor="%s">%d%s</text>\n!,
      coor( 40, 100 * $_ ), 28, "middle", 100 * $_, "號";
}

my @d = (
    { color => "red",  oe => "雙號 Even" },
    { color => "blue", oe => "單號 Odd" },
);

for ( 0, 1 ) {
    printf    #ODD EVEN notice
      qq! <text x="%d" y="%d" font-size="%d" text-anchor="%s" fill="%s">%s</text>\n!,
      coor( $Z / 2, $Z - 100 - 50 * !$_ ), 34, "middle", $d[$_]{color},
      $d[$_]{oe};
    ##The actual points
    open( my $fh, "<", shift @ARGV )
      or die "$!";
    my @points;
    while ( my $line = readline($fh) ) {
        next unless $line =~ /\d/;
        my @F = split /,/, $line;
        push @points, join ",", coor(@F);
        printf
          qq{ <circle cx="%d" cy="%d" r="3" stroke="%s"/>\n},
          coor(@F), $d[$_]{color};
    }
    print
      qq{ <polyline stroke-width="1" fill="none" stroke="$d[$_]{color}" points="};
    print qq{@points"/>\n};
    close $fh;
}
print "</svg>\n";

sub coor {    # flip axis for SGV
    return $_[0], $Z - $_[1];
}