Math::PlanePath::Rows(3pm)

Usage

 use Math::PlanePath::Rows;
 my $path = Math::PlanePath::Rows->new (width => 20);
 my ($x, $y) = $path->n_to_xy (123);

Overview

This path is rows of a given fixed width. For example width=7 is

    width => 7
      3  |  22  23  24 ...
      2  |  15  16  17  18  19  20  21
      1  |   8   9  10  11  12  13  14
    Y=0  |   1   2   3   4   5   6   7
          -------------------------------
           X=0   1   2   3   4   5   6

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, width => 7
      3  |  21  22  23  24 ...
      2  |  14  15  16  17  18  19  20
      1  |   7   8   9  10  11  12  13
    Y=0  |   0   1   2   3   4   5   6
          -------------------------------
           X=0   1   2   3   4   5   6

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::Rows->new (width => $w)"

"$path = Math::PlanePath::Rows->new (width => $w, n_start => $n)": Create and return a new path object. A "width" 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 column -0.5 <= x < width+0.5 and y>=-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>

Releases

6 releases since Debian 8 (Jessie); the text changed 3 times.