NAME

Collision::2D::Entity - A moving entity. Don't use this directly.

DESCRIPTION

ATTRIBUTES

x,y,xv,yv

Absolute position and velocity in space. These are necessary if you want to do collisions through dynamic_collision

 dynamic_collision($circ1, $circ2);

relative_x, relative_y, relative_xv, relative_yv

You shouldn't worry about these. Move along now.

Relative position and velocity in space. these are necessary if you want to do collisions directly through entity methods,

 $circ1->_collide_circle($circ2);

In this case, both the absolute and relative position and velocity of $circ2 is not used. The relative attributes of $circ1 are assumed to be relative to $circ2.

METHODS

collide

 my $collision = $self->collide ($other_entity, interval=>4);

Detect collision with another entity. $self must be normalized to $other. Takes interval as a parameter. Returns a collision if there is a collision. Returns undef if there is no collision.

With the collide method, the entity order is preserved. Consider this example:

 my $collision1 = $panel->collide($droplet);
 my $collision2 = $droplet->collide($panel);

If these objects collide, then its $collision1-ent1> will be $panel, and $collision2-ent1> will be $droplet.

intersect

 my $t_or_f = $self->intersect ($other_entity, interval=>2.5);

Detect intersection (overlapping) with another entity. Takes interval as a parameter. Returns a collision if there is a collision. Returns undef if there is no collision.

interval is optional. interval is 1 by default.

Relative vectors and velocity are not considered for intersection.

normalize

You probably shouldn't use this directly. At all. Relative vectors are handled automatically in dynamic_collision and in $ent1-collide($ent2)>

 $self->normalize($other); # $other isa entity

This compares the absolute attributes of $self and $other. It only sets the relative attributes of $self. This is necessary to call _collide_*($other) methods on $self.