NAME
Math::PlanePath::Rows  points in fixedwidth rows
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.
SEE ALSO
Math::PlanePath, Math::PlanePath::Columns
HOME PAGE
http://user42.tuxfamily.org/mathplanepath/index.html
LICENSE
Copyright 2010, 2011, 2012, 2013, 2014 Kevin Ryde
This 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/>.