#!/usr/bin/perl
# Make some line grids...
# Author: Dan Jacobson https://www.jidanni.org/
# Copyright: https://www.gnu.org/licenses/gpl.html
# Created: 2024-05-26T00:05:40+0000
# Last-Updated: 2024-05-29T00:05:40+0000
#     Update #: 78
#
use strict;
use warnings q!all!;
use Getopt::Long;
my $mode;      #which axis, 0 is E/W axis, 1 is N/S
my $numbers_per_grid;
my $offset;    # to avoid putting points on top of road intersections,
## and thus avoid confusion about which road our numbers are referring to.
my $rows
  ; ## How many rows of labels do we want? E.g., 6 gives 6 vertical and 6 horizontal.
my @range;    ##--range -1200 200 means 1200 S or W to 200 N or E

GetOptions(
    "mode=i"              => \$mode,
    "numbers_per_grid=i" => \$numbers_per_grid,
    "offset=i"            => \$offset,
    "rows=i"              => \$rows,
    "range=i{2}"          => \@range,
) or die("Error in command line arguments\n");
die "No mode (0 or 1) given."                 unless defined $mode;
die "We weren't told how many --rows"         unless $rows;
die "We don't know the --range start and end" unless @range == 2;
unless ( defined $offset ) {
    $offset = $numbers_per_grid / 2;
}
{
    my @tmp = @range;
    undef @range;
    for ( my $v = $tmp[0] ; $v <= $tmp[1] ; $v += $numbers_per_grid ) {
        push @range, $v;
    }
}
$rows--;
my @row_pointer;
for ( 0 .. $rows ) {
    push @row_pointer, $range[ $#range / $rows * $_ ];
}
for my $a (@row_pointer) {
    for my $b (@range) {
        my @to_print;
        push @to_print,
          ( $mode  ? $a : $b ) + $offset * $mode,
          ( !$mode ? $a : $b ) + $offset * !$mode;
        push @to_print, $to_print[$mode],
          abs( $to_print[$mode] )
          . (
            $mode
            ? ( $to_print[$mode] >= 0 ? "N" : "S" )
            : ( $to_print[$mode] >= 0 ? "E" : "W" )
          );
        print "@to_print$/";
    }
}