B2.World:rayCast

Available since: Gideros 2011.6

Description

Ray-cast the world for all fixtures in the path of the ray. Your callback controls whether you get the closest point, any point, or n-points. The ray-cast ignores shapes that contain the starting point.

Listener function is called for each fixture found in the query and accepts 6 parameters (7 if data parameter is provided):

1. the fixture hit by the ray
2. the x coordinate of the point of initial intersection
3. the y coordinate of the point of initial intersection
4. the x coordinate of the normal vector at the point of intersection
5. the y coordinate of the normal vector at the point of intersection
6. fraction

You control how the ray cast proceeds by returning a number:

<ul>
<li>return no value or -1: ignore this fixture and continue</li>
<li>return 0: terminate the ray cast</li>
<li>return fraction: clip the ray to this point</li>
<li>return 1: don't clip the ray and continue</li>
</ul>

= b2.World:rayCast(x1y1x2y2listenerdata,)

'x1: (number) the x coordinate of the ray starting point '
'y1: (number) the y coordinate of the ray starting point '
'x2: (number) the x coordinate of the ray ending point '
'y2: (number) the y coordinate of the ray ending point '
'listener: (function) the listener function that processes the results '
data: (any) an optional data parameter that is passed as a first argument to the listener function optional