File Coverage

blib/lib/Game/TextMapper/Schroeder/Square.pm

Criterion	Covered	Total	%
statement	29	33	87.8
branch	7	12	58.3
condition			n/a
subroutine	10	11	90.9
pod	9	9	100.0
total	55	65	84.6

# Copyright (C) 2009-2021  Alex Schroeder
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option) any
# later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see .

=encoding utf8

=head1 NAME

Game::TextMapper::Schroeder::Square - a role for square map generators

=head1 SYNOPSIS

    # create a map
    package World;
    use Modern::Perl;
    use Mojo::Base -base;
    use Role::Tiny::With;
    with 'Game::TextMapper::Schroeder::Base';
    with 'Game::TextMapper::Schroeder::Square';
    # use it
    package main;
    my $map = World->new(height => 10, width => 10);

=head1 DESCRIPTION

This role provides basic functionality for map generation with square maps: the
number of neighbours within one or two regions distance, how to pick a random
neighbour direction, how to compute the coordinates of these neighbours, how to
draw arrows towards these neighbours.

This inherits attributes and methods from L,
such as C and C.

=cut

package Game::TextMapper::Schroeder::Square;
use Modern::Perl '2018';
use Mojo::Base -role;

=head1 METHODS

=head2 reverse

Reverses a direction.

=cut

sub reverse {
  my ($self, $i) = @_;
  return ($i + 2) % 4;
}

=head2 neighbors

The list of directions for neighbours one step away (0 to 3).

=cut

sub neighbors { 0 .. 3 }

=head2 neighbors2

The list of directions for neighbours two steps away (0 to 7).

=cut

sub neighbors2 { 0 .. 7 }

=head2 random_neighbor

A random direction for a neighbour one step away (a random integer from 0 to 3).

=cut

sub random_neighbor { int(rand(4)) }

=head2 random_neighbor2

A random direction for a neighbour two steps away (a random integer from 0 to
7).

=cut

sub random_neighbor2 { int(rand(8)) }

my $delta_square = [[-1,  0], [ 0, -1], [+1,  0], [ 0, +1]];

=head2 neighbor($square, $i)

    say join(",", $map->neighbor("0203", 1));
    # 2,2

Returns the coordinates of a neighbor in a particular direction (0 to 3), one
step away.

C<$square> is an array reference of coordinates or a string that can be turned
into one using the C method from L.

C<$i> is a direction (0 to 3).

=cut

sub neighbor {
  my $self = shift;
  # $hex is [x,y] or "0x0y" and $i is a number 0 .. 3
  my ($hex, $i) = @_;
  die join(":", caller) . ": undefined direction for $hex\n" unless defined $i;
  $hex = [$self->xy($hex)] unless ref $hex;
  return ($hex->[0] + $delta_square->[$i]->[0],
	  $hex->[1] + $delta_square->[$i]->[1]);
}

my $delta_square2 = [
  [-2,  0], [-1, -1], [ 0, -2], [+1, -1],
  [+2,  0], [+1, +1], [ 0, +2], [-1, +1]];

=head2 neighbor2($square, $i)

    say join(",", $map->neighbor2("0203", 1));
    # 1, 2

Returns the coordinates of a neighbor in a particular direction (0 to 7), two
steps away.

C<$square> is an array reference of coordinates or a string that can be turned
into one using the C method from L.

C<$i> is a direction (0 to 3).

=cut

sub neighbor2 {
  my $self = shift;
  # $hex is [x,y] or "0x0y" and $i is a number 0 .. 7
  my ($hex, $i) = @_;
  die join(":", caller) . ": undefined direction for $hex\n" unless defined $i;
  die join(":", caller) . ": direction $i not supported for square $hex\n" if $i > 7;
  $hex = [$self->xy($hex)] unless ref $hex;
  return ($hex->[0] + $delta_square2->[$i]->[0],
	  $hex->[1] + $delta_square2->[$i]->[1]);
}

=head2 distance($x1, $y1, $x2, $y2) or distance($coords1, $coords2)

    say $map->distance("0203", "0003");
    # 2

Returns the distance between two coordinates.

=cut

sub distance {
  my $self = shift;
  my ($x1, $y1, $x2, $y2) = @_;
  if (@_ == 2) {
    ($x1, $y1, $x2, $y2) = map { $self->xy($_) } @_;
  }
  return abs($x2 - $x1) + abs($y2 - $y1);
}

=head2 arrows

A helper that returns the SVG fragments for arrows in four directions, to be
used in a C element.

=cut

sub arrows {
  my $self = shift;
  return
      qq{},
      qq{},
      map {
	my $angle = 90 * $_;
	qq{},
	qq{},
  } ($self->neighbors());
}

=head1 SEE ALSO

L
L

=cut

1;