/ 
Math-PlanePath-20
River stage one • 3 direct dependents • 4 total dependents
/ Math::PlanePath::PentSpiralSkewed

NAME

Math::PlanePath::PentSpiralSkewed -- integer points in a pentagonal shape

SYNOPSIS

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

DESCRIPTION

This path makes a pentagonal (five-sided) spiral with points skewed so as to fit a square grid and fully cover the plane.

      10 ...             2
     /  \  \
   11  3  9 20           1
  /  /  \  \  \
12  4  1--2  8 19    <- y=0
  \  \       |  | 
   13  5--6--7 18       -1
     \          |    
      14-15-16-17       -2
           
 ^  ^  ^  ^  ^  ^ 
-2 -1 x=0 1  2  3 ...

The pattern is similar to the SquareSpiral but cuts three corners which makes each cycle is faster. Each cycle is just 5 steps longer than the previous (where it's 8 for a SquareSpiral).

FUNCTIONS

$path = Math::PlanePath::PentSpiral->new ()

Create and return a new PentSpiral spiral object.

($x,$y) = $path->n_to_xy ($n)

Return the x,y coordinates of point number $n on the path.

For $n < 1 the return is an empty list, it being considered the path starts at 1.

$n = $path->xy_to_n ($x,$y)

Return the point number for coordinates $x,$y. $x and $y are each rounded to the nearest integer, which has the effect of treating each point in the path as a square of side 1.

SEE ALSO

Math::PlanePath, Math::PlanePath::SquareSpiral, Math::PlanePath::DiamondSpiral, Math::PlanePath::HexSpiralSkewed

HOME PAGE

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

LICENSE

Math-PlanePath is Copyright 2010, 2011 Kevin Ryde

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.

You should have received a copy of the GNU General Public License along with Math-PlanePath. If not, see <http://www.gnu.org/licenses/>.