man Math::PlanePath::Columns (3): points in fixed-height columns

SYNOPSIS

use Math::PlanePath::Columns;
my $path = Math::PlanePath::Columns->new;
my ($x, $y) = $path->n_to_xy (123);

DESCRIPTION

This path is columns of a given fixed height. For example height 5 would be

         |
      4  |   5  10  15  20        <---  height==5
      3  |   4   9  14  19
      2  |   3   8  13  18
      1  |   2   7  12  17  ...
    Y=0  |   1   6  11  16  21 
          ----------------------
           X=0   1   2   3   4  ...

N Start

The default is to number points starting N=1 as shown above. An optional "n_start" can give a different start, with the same shape. For example to start at 0,

    n_start => 0, height => 5
      4  |   4   9  14  19 
      3  |   3   8  13  18 
      2  |   2   7  12  17 
      1  |   1   6  11  16  ...
    Y=0  |   0   5  10  15  20
          ----------------------
           X=0   1   2   3   4  ...

The only effect is to push the N values around by a constant amount. It might help match coordinates with something else zero-based.

FUNCTIONS

See ``FUNCTIONS'' in Math::PlanePath for behaviour common to all path classes.

"$path = Math::PlanePath::Columns->new (height => $h)"
"$path = Math::PlanePath::Columns->new (height => $h, n_start => $n)": Create and return a new path object. A "height" parameter must be supplied.
"($x,$y) = $path->n_to_xy ($n)": Return the X,Y coordinates of point number $n in the path.
"$n = $path->xy_to_n ($x,$y)": Return the point number for coordinates "$x,$y".
$x and $y are rounded to the nearest integers, which has the effect of treating each point in the path as a square of side 1, so a rectangle $x >= -0.5 and -0.5 <= y < height+0.5 is covered.
"($n_lo, $n_hi) = $path->rect_to_n_range ($x1,$y1, $x2,$y2)": The returned range is exact, meaning $n_lo and $n_hi are the smallest and biggest in the rectangle.

HOME PAGE

<http://user42.tuxfamily.org/math-planepath/index.html>

LICENSE

This file is part of Math-PlanePath.

Math-PlanePath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

Math-PlanePath 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 General Public License for more details.