#!/usr/bin/perl -w
# Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017 Kevin Ryde
# 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.
#
# You should have received a copy of the GNU General Public License along
# with Math-PlanePath. If not, see <http://www.gnu.org/licenses/>.
use 5.004;
use strict;
use Test;
plan tests => 624;
use lib 't';
use MyTestHelpers;
BEGIN { MyTestHelpers::nowarnings(); }
# uncomment this to run the ### lines
#use Devel::Comments;
require Math::PlanePath::DragonCurve;
#------------------------------------------------------------------------------
# VERSION
{
my $want_version = 124;
ok ($Math::PlanePath::DragonCurve::VERSION, $want_version,
'VERSION variable');
ok (Math::PlanePath::DragonCurve->VERSION, $want_version,
'VERSION class method');
ok (eval { Math::PlanePath::DragonCurve->VERSION($want_version); 1 },
1,
"VERSION class check $want_version");
my $check_version = $want_version + 1000;
ok (! eval { Math::PlanePath::DragonCurve->VERSION($check_version); 1 },
1,
"VERSION class check $check_version");
my $path = Math::PlanePath::DragonCurve->new;
ok ($path->VERSION, $want_version, 'VERSION object method');
ok (eval { $path->VERSION($want_version); 1 },
1,
"VERSION object check $want_version");
ok (! eval { $path->VERSION($check_version); 1 },
1,
"VERSION object check $check_version");
}
#----------------------------------------------------------------------------
# n_to_dxdy()
{
my $path = Math::PlanePath::DragonCurve->new;
{ my @dxdy = $path->n_to_dxdy(-1);
ok (scalar(@dxdy), 0);
}
{ my @dxdy = $path->n_to_dxdy(0);
ok (scalar(@dxdy), 2);
ok ($dxdy[0], 1);
ok ($dxdy[1], 0);
}
}
#----------------------------------------------------------------------------
# _UNDOCUMENTED__n_to_turn_LSR()
{
my $path = Math::PlanePath::DragonCurve->new;
ok ($path->_UNDOCUMENTED__n_to_turn_LSR(-1), undef);
ok ($path->_UNDOCUMENTED__n_to_turn_LSR(0), undef);
ok ($path->_UNDOCUMENTED__n_to_turn_LSR(1), 1);
ok ($path->_UNDOCUMENTED__n_to_turn_LSR(2), 1);
ok ($path->_UNDOCUMENTED__n_to_turn_LSR(3), -1);
}
#------------------------------------------------------------------------------
# level_to_n_range()
{
my $path = Math::PlanePath::DragonCurve->new;
{ my ($n_lo,$n_hi) = $path->level_to_n_range(0);
ok ($n_lo, 0);
ok ($n_hi, 1); }
{ my ($n_lo,$n_hi) = $path->level_to_n_range(1);
ok ($n_lo, 0);
ok ($n_hi, 2); }
{ my ($n_lo,$n_hi) = $path->level_to_n_range(2);
ok ($n_lo, 0);
ok ($n_hi, 4); }
{ my ($n_lo,$n_hi) = $path->level_to_n_range(3);
ok ($n_lo, 0);
ok ($n_hi, 8); }
}
{
my $path = Math::PlanePath::DragonCurve->new (arms => 3);
{ my ($n_lo,$n_hi) = $path->level_to_n_range(0);
ok ($n_lo, 0);
ok ($n_hi, 3*(2**0 + 1) - 1); }
{ my ($n_lo,$n_hi) = $path->level_to_n_range(1);
ok ($n_lo, 0);
ok ($n_hi, 3*(2**1 + 1) - 1); }
{ my ($n_lo,$n_hi) = $path->level_to_n_range(2);
ok ($n_lo, 0);
ok ($n_hi, 3*(2**2 + 1) - 1); }
{ my ($n_lo,$n_hi) = $path->level_to_n_range(3);
ok ($n_lo, 0);
ok ($n_hi, 3*(2**3 + 1) - 1); }
}
#------------------------------------------------------------------------------
# turn sequence claimed in the pod
{
# with Y reckoned increasing upwards
sub dxdy_to_dir4 {
my ($dx, $dy) = @_;
if ($dx > 0) { return 0; } # east
if ($dx < 0) { return 2; } # west
if ($dy > 0) { return 1; } # north
if ($dy < 0) { return 3; } # south
}
sub path_n_dir {
my ($path, $n) = @_;
my ($dx,$dy) = $path->n_to_dxdy($n) or die "Oops, no point at ",$n;
return dxdy_to_dir4 ($dx, $dy);
}
# return 0 for left, 1 for right
sub path_n_turn {
my ($path, $n) = @_;
my $prev_dir = path_n_dir ($path, $n-1);
my $dir = path_n_dir ($path, $n);
my $turn = ($dir - $prev_dir) % 4;
if ($turn == 1) { return 0; }
if ($turn == 3) { return 1; }
die "Oops, unrecognised turn dir=$dir";
}
# return 0 for left, 1 for right
sub calc_n_turn {
my ($n) = @_;
my ($mask,$z);
$mask = $n & -$n; # lowest 1 bit, 000100..00
$z = $n & ($mask << 1); # the bit above it
my $turn = ($z == 0 ? 0 : 1);
# printf "%b %b %b %d\n", $n,$mask, $z, $turn;
return $turn;
die if $n == 0;
while (($n % 2) == 0) {
$n = int($n/2); # skip low 0s
}
$n = int($n/2); # skip lowest 1
return ($n % 2); # next bit is the turn
}
#
# return 0 for left, 1 for right
sub calc_n_next_turn {
my ($n) = @_;
my ($mask,$w);
$mask = $n ^ ($n+1); # low one and below 000111..11
$w = $n & ($mask + 1); # the bit above there
my $turn = ($w == 0 ? 0 : 1);
return $turn;
}
my $path = Math::PlanePath::DragonCurve->new;
my $bad = 0;
foreach my $n ($path->n_start + 1 .. 500) {
{
my $path_turn = path_n_turn ($path, $n);
my $calc_turn = calc_n_turn ($n);
if ($path_turn != $calc_turn) {
MyTestHelpers::diag ("turn n=$n path $path_turn calc $calc_turn");
last if $bad++ > 10;
}
}
{
my $path_turn = path_n_turn ($path, $n+1);
my $calc_turn = calc_n_next_turn ($n);
if ($path_turn != $calc_turn) {
MyTestHelpers::diag ("next turn n=$n path $path_turn calc $calc_turn");
last if $bad++ > 10;
}
}
}
ok ($bad, 0, "turn sequence");
}
#------------------------------------------------------------------------------
# n_start, x_negative, y_negative
{
my $path = Math::PlanePath::DragonCurve->new;
ok ($path->n_start, 0, 'n_start()');
ok ($path->x_negative, 1, 'x_negative()');
ok ($path->y_negative, 1, 'y_negative()');
ok ($path->class_x_negative, 1, 'class_x_negative()');
ok ($path->class_y_negative, 1, 'class_y_negative()');
}
{
my @pnames = map {$_->{'name'}}
Math::PlanePath::DragonCurve->parameter_info_list;
ok (join(',',@pnames), 'arms');
}
#------------------------------------------------------------------------------
# first few points
{
my @data = (
[ 0, 0,0 ],
[ 1, 1,0 ],
[ 2, 1,1 ],
[ 3, 0,1 ],
[ 4, 0,2 ],
[ 0.25, 0.25, 0 ],
[ 1.25, 1, 0.25 ],
[ 2.25, 0.75, 1 ],
[ 3.25, 0, 1.25 ],
);
my $path = Math::PlanePath::DragonCurve->new;
foreach my $elem (@data) {
my ($n, $x, $y) = @$elem;
{
# n_to_xy()
my ($got_x, $got_y) = $path->n_to_xy ($n);
if ($got_x == 0) { $got_x = 0 } # avoid "-0"
if ($got_y == 0) { $got_y = 0 }
ok ($got_x, $x, "n_to_xy() x at n=$n");
ok ($got_y, $y, "n_to_xy() y at n=$n");
}
if ($n==int($n)) {
# xy_to_n()
my $got_n = $path->xy_to_n ($x, $y);
ok ($got_n, $n, "xy_to_n() n at x=$x,y=$y");
}
{
$n = int($n);
my ($got_nlo, $got_nhi) = $path->rect_to_n_range (0,0, $x,$y);
ok ($got_nlo <= $n, 1, "rect_to_n_range() nlo=$got_nlo at n=$n,x=$x,y=$y");
ok ($got_nhi >= $n, 1, "rect_to_n_range() nhi=$got_nhi at n=$n,x=$x,y=$y");
}
}
}
#------------------------------------------------------------------------------
# random rect_to_n_range()
foreach my $arms (1 .. 4) {
my $path = Math::PlanePath::DragonCurve->new (arms => $arms);
ok ($path->arms_count, $arms, 'arms_count()');
for (1 .. 5) {
my $bits = int(rand(25)); # 0 to 25, inclusive
my $n = int(rand(2**$bits)); # 0 to 2^bits, inclusive
my ($x,$y) = $path->n_to_xy ($n);
my $rev_n = $path->xy_to_n ($x,$y);
ok (defined $rev_n, 1, "xy_to_n($x,$y) arms=$arms reverse n, got undef");
my ($n_lo, $n_hi) = $path->rect_to_n_range ($x,$y, $x,$y);
ok ($n_lo <= $n, 1,
"rect_to_n_range() arms=$arms n=$n at xy=$x,$y cf got n_lo=$n_lo");
ok ($n_hi >= $n, 1,
"rect_to_n_range() arms=$arms n=$n at xy=$x,$y cf got n_hi=$n_hi");
}
}
#------------------------------------------------------------------------------
# random n_to_xy() fracs
foreach my $arms (1 .. 4) {
my $path = Math::PlanePath::DragonCurve->new (arms => $arms);
for (1 .. 20) {
my $bits = int(rand(25)); # 0 to 25, inclusive
my $n = int(rand(2**$bits)) + 1; # 1 to 2^bits, inclusive
my ($x1,$y1) = $path->n_to_xy ($n);
my ($x2,$y2) = $path->n_to_xy ($n+$arms);
foreach my $frac (0.25, 0.5, 0.75) {
my $want_xf = $x1 + ($x2-$x1)*$frac;
my $want_yf = $y1 + ($y2-$y1)*$frac;
my $nf = $n + $frac;
my ($got_xf,$got_yf) = $path->n_to_xy ($nf);
ok ($got_xf, $want_xf, "n_to_xy($nf) arms=$arms frac $frac, x");
ok ($got_yf, $want_yf, "n_to_xy($nf) arms=$arms frac $frac, y");
}
}
}
exit 0;