package Math::Path;
#	This program is free software; you can redistribute it and/or
#	modify it under the terms of the GNU LGPL Libray General Public License
#	as published by the Free Software Foundation; either version 2
#	of the License, or (at your option) any later version.
#
#	This program 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 Library General Public License for more details.
#
#	You should have received a copy of the GNU Library General Public License
#	along with this program; if not, write to the Free Software
#	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA,
#	or refer to http://www.gnu.org/copyleft/lgpl.html
#
##################################################################

use strict;
our $recursive_depth = 2;

sub new {
	my ($class, @coords) = @_;
	my $self = {};
	bless $self, $class;
	$self -> {content} = ();
	my @path = ();
	my $tmp = [];
	
	for (my $i = 0; $i < @coords; $i ++)
	{
		my @arr = @{$coords [$i]};
		if (@arr == 3)
		{
			push (@{$tmp}, \@arr);
		}
		else
		{
			push (@{$tmp}, \@arr);
			push (@path, $tmp);
			$tmp = [];
		}
	}	
	$self -> {curves} = \@path;
	$self -> {lastPoint} = undef;
	$self -> {lenght} = 0;
	$self -> update ();
	return $self;
}	
	
sub drawLine {
	my ($self, $x0, $y0, $x1, $y1) = @_;
	if (!defined $self -> {content} || @{$self -> {content}} == 0)
	{
		push (@{$self -> {content}}, [$x0, $y0]);
	}
	push (@{$self -> {content}}, [$x1, $y1]);
}

sub _calcul_lenght {
	my ($self) = @_;
	my @content = @{$self -> {content}};
	my $x = $content [0] -> [0];
	my $y = $content [0] -> [1];
	my $lenght = 0;
	for (my $i = 0; $i < @content; $i ++)
	{
		my $dx = $content [$i] -> [0] - $x;
		my $dy = $content [$i] -> [1] - $y;
		my $d = sqrt (($dx) ** 2 + ($dy) ** 2);
		$lenght += $d;
		$x = $content [$i] -> [0];
		$y = $content [$i] -> [1];
	}
	$self -> {lenght} = $lenght;
}

sub drawBezierRecursive {
	my ($self, $p0, $p1, $p2, $p3, $level) = @_;
	if ($level <= 0) 
	{
		$self -> drawLine ($p0 -> [0] + 0.5, $p0 -> [1] + 0.5, $p3 -> [0] + 0.5, $p3 -> [1] + 0.5);
	}
	else
	{
		my $left0 = [$p0 -> [0], $p0 -> [1]];
		my $left1 = [($p0 -> [0] + $p1 -> [0]) / 2, ($p0 -> [1] + $p1 -> [1]) / 2];
		my $left2 = [($p0 -> [0] + 2*$p1 -> [0] + $p2 -> [0]) / 4, ($p0 -> [1] + 2*$p1 -> [1] + $p2 -> [1]) / 4];
		my $left3 = [($p0 -> [0] + 3*$p1 -> [0] + 3*$p2 -> [0] + $p3 -> [0]) / 8, ($p0 -> [1] + 3*$p1 -> [1] + 3*$p2 -> [1] + $p3 -> [1]) / 8];
		my $right0 = [$left3 -> [0], $left3 -> [1]];
		my $right1 = [($p1 -> [0] + 2*$p2 -> [0] + $p3 -> [0]) / 4, ($p1 -> [1] + 2*$p2 -> [1] + $p3 -> [1]) / 4];
		my $right2 = [($p2 -> [0] + $p3 -> [0]) / 2, ($p2 -> [1] + $p3 -> [1]) / 2];
		my $right3 = [$p3 -> [0],$p3 -> [1]];
		$self -> drawBezierRecursive ($left0, $left1, $left2, $left3, $level -1);
		$self -> drawBezierRecursive ($right0, $right1, $right2, $right3, $level -1);
	}
}

sub update {
	my ($self) = @_;
	my @curr_curve = ();
	$self -> {content} = ();
	$self -> {lastPoint} = undef;
	my @curves = @{$self -> {curves}};
	for (my $i = 0; $i < @curves; $i++)
	{
		@curr_curve = @{$curves [$i]};
		if (@curr_curve == 1)
		{
			push (@{$self -> {content}}, $curr_curve [0]);
			$self -> {lastPoint} = $curr_curve [0];
		}
		elsif (@curr_curve == 2)
		{
			push (@{$self -> {content}}, $curr_curve [0]);
			push (@{$self -> {content}}, $curr_curve [1]);
			$self -> {lastPoint} = $curr_curve [1];
		}
		elsif (@curr_curve == 3)
		{
			$self -> drawBezierRecursive ($self -> {lastPoint}, $curr_curve [0], $curr_curve [1], $curr_curve [2], $recursive_depth);
			$self -> {lastPoint} = $curr_curve [2];
		}
		elsif (@curr_curve == 4)
		{
			$self -> drawBezierRecursive ($curr_curve [0], $curr_curve [1], $curr_curve [2], $curr_curve [3], $recursive_depth);
			$self -> {lastPoint} = $curr_curve [3];
		}
	}
	$self -> _calcul_lenght ();
}

sub getRegularPoints {
	my ($self, $nb) = @_;
	my @points = ();
	my $troncon = $self -> {lenght} / $nb;
	my @content = @{$self -> {content}};
	my $current_troncon = 0;
	my $x = $content [0] -> [0];
	my $y = $content [0] -> [1];
	my $dx = 1;
	my $dy = 1;
	my $lenght = 0;
	for (my $i = 0; $i < @content; $i ++)
	{
		$dx = $content [$i] -> [0] - $x;
		$dy = $content [$i] -> [1] - $y;
		
		my $d = sqrt (($dx) ** 2 + ($dy) ** 2);
		$lenght += $d;
		$current_troncon += $d;
		while ($current_troncon >= $troncon)
		{
			my $dtp = $troncon - ($current_troncon - $d);
			my $px = $x + $dx * $dtp / $d;
			my $py = $y + $dy * $dtp / $d;
			$x = $px;
			$y = $py;
			$d -= $dtp;
			$dx = $content [$i] -> [0] - $x;
			$dy = $content [$i] -> [1] - $y;
			$current_troncon -= $troncon;
			push (@points, [$x, $y, atan2 ($dx, $dy)]);
		}
		
		$x = $content [$i] -> [0];
		$y = $content [$i] -> [1];
	}
	push (@points, [$x, $y, atan2 ($dx, $dy)]);
	return @points;
}