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lib/AI/Pathfinding/SMAstar/Path.pm  view on Meta::CPAN

{    
    my ($self) = @_;
    
    my $fcost = $self->{_f_cost};
    if(defined($fcost)){	    
	return $fcost;
    }

    my $eval_func = $self->{_eval_func};
    my $result =  $eval_func->($self->{_state});
    $self->{_f_cost} = $result;

    return $result;
}





sub is_goal
{
    my ($self) = @_;
      
    my $goal_p_func = $self->{_goal_p_func};
    my $result =  $goal_p_func->($self->{_state});

    return $result;
}



sub get_num_successors
{
    my ($self) = @_;
      
    my $num_successors_func = $self->{_num_successors_func};
    my $result =  $num_successors_func->($self->{_state});

    return $result;    
}


sub get_successors_iterator
{
    my ($self) = @_;
      
    my $successors_iterator = $self->{_successors_iterator};

    my $iterator = $successors_iterator->($self->{_state});
    
    return $iterator;    
}


    
    

#-----------------------------------------------------------------------------------------------
#
# Check whether we need to backup the fvals for a node when it is completed (recursive)
# Sets flags throughout path object's lineage, indicating whether fvals need to be updated.
#
#-----------------------------------------------------------------------------------------------
sub check_need_fval_change
{
    my ($self, $descendant_fcost, $descendant_ind) = @_;
 

    my $descendant_index = $self->{_descendant_index};

    if(!$self->is_completed()){
        # node not completed. no need to update fcost.
	$self->need_fval_change(0);
	return;
    }

    my $fcost = $self->{_f_cost};
    my $least_fcost2 = 99;
       
    
    my $min = sub {	
	my ($n1, $n2) = @_;
	return ($n1 < $n2 ? $n1 : $n2);
    };

    if($self->{_forgotten_nodes_num} != 0){ 
	foreach my $ind (keys %{$self->{_forgotten_nodes_offsets}}){	  
	    my $cost = $self->{_forgotten_node_fcosts}->[$ind];	    
	    if($cost != -1 && $cost < $least_fcost2){
		$least_fcost2 = $cost;
	    }		    
	}
    }    
   
    my $j = 0;
    foreach my $fc (@{$self->{_descendant_fcosts}}){
	if(defined($descendant_ind) && $j != $descendant_ind){
	    if($fc != -1 && $fc < $least_fcost2){
		$least_fcost2 = $fc;
	    }
	}
	else{
	    # special case for index $j:  it is the caller's index.
	    if(defined($descendant_fcost)){	
		if($descendant_fcost < $least_fcost2) {
		    $least_fcost2 = $descendant_fcost;
		}
	    }
	    elsif($fc != -1 && $fc < $least_fcost2){
		$least_fcost2 = $fc;
	    }
	}	
	$j++;	
    }
    
    # if no successors, this node cannot lead to 
    # goal, so set fcost to infinity.
    if($self->{_num_successors} == 0){ 
	$least_fcost2 = 99;
    }