SYNOPSIS
use Math::PlanePath::Rows;
my $path = Math::PlanePath::Rows>new (width => 20);
my ($x, $y) = $path>n_to_xy (123);
DESCRIPTION
This path is rows of a given fixed width. For example width=7 is
width => 7 3  22 23 24 ... 2  15 16 17 18 19 20 21 1  8 9 10 11 12 13 14 Y=0  1 2 3 4 5 6 7  X=0 1 2 3 4 5 6
N Start
The default is to number points starting N=1 as shown above. An optional "n_start" can give a different start, with the same shape. For example to start at 0,
n_start => 0, width => 7 3  21 22 23 24 ... 2  14 15 16 17 18 19 20 1  7 8 9 10 11 12 13 Y=0  0 1 2 3 4 5 6  X=0 1 2 3 4 5 6
The only effect is to push the N values around by a constant amount. It might help match coordinates with something else zerobased.
FUNCTIONS
See ``FUNCTIONS'' in Math::PlanePath for behaviour common to all path classes. "$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.
LICENSE
Copyright 2010, 2011, 2012, 2013, 2014, 2015, 2016 Kevin RydeThis file is part of MathPlanePath.
MathPlanePath 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.
MathPlanePath 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.
You should have received a copy of the GNU General Public License along with MathPlanePath. If not, see <http://www.gnu.org/licenses/>.