"""Callback function to the collide method."""

#Get collision props objects if they exist

g1_coll_props = getattr(geom1, "coll_props", None)

g2_coll_props = getattr(geom2, "coll_props", None)

#If both geoms either have collision properties or are spaces, then perform a collision

if g1_coll_props != None and g2_coll_props != None:

g1_coll_props.handle_collision(geom1, geom2, contactgroup)

elif (geom1.isSpace() or g1_coll_props != None) and (geom2.isSpace() or g2_coll_props != None):

"""Describes a collision that took place between two ODE geoms.

This object is meant to be kept in sub-arrays of the app.collisions dictionary. That dictionary

is keyed by the id of a geom, so this object only need to keep track of the 2nd geom that the

key geom collided with.

Data attributes:

geom -- The ODE geom that the key geom collided with.

pos -- An array of all the points where the objects collide; weirdly-shaped objects can collide in several spots.

avg_pos -- Average Point of cpoints, in absolute coordinates.

"""

def __init__(self, geom, cpoints):

self.geom = geom

self.cpoints = cpoints[:]

self.avg_pos = Point(0,0)

for p in cpoints:

self.avg_pos += p

"""Defines the collision properties of some object.

The basis of the intersec_pri stuff it that is that two objects that

collide physically may require either a ContactJoint between them if they've

got equal collision priority, or may require a ContactJoint between the world

and the one with lesser priority. There's no reason I can think of now

to have any more than two layers of priority, but what the heck. The point

of this system is to allow things like moving platforms that have bodies

and geoms but cannot be pushed around by the player, although they can push

the player around.

All collisions are logged to

Data attributes:

intersec_push -- If True, creates contact joints at intersections to push this object, the other, or both away.

Both objects must have this flag on for any intersection prevention to occur.

intersec_pri -- The numeric collision priority for intersection-stopping (defaults to 1).

"""

def __init__(self, intersec_push = True, intersec_pri = 1):

self.intersec_push = intersec_push

self.intersec_pri = intersec_pri

def handle_collision(self, geom1, geom2, cjointgroup):

"""Checks for a real collision between geom1 (which should be the geom that has this Props as a

.coll_props data attribute) and some other geom, also with a valid .coll_props. If there is a

collision, then entries are made in app.collisions. Furthermore, if both objects have intersec_push

enabled in their coll_props, then contact joints are created to push the objects apart.

For any given collision, this is only called once, so this method needs to handle

both this object's reaction as well as the other's.

Newly created contact joints are placed into cjointgroup."""

contacts = ode.collide(geom1, geom2)

# Add the collision to app.collisions

if len(contacts) > 0:

cpoints = []

for c in contacts:

cpoints.append(Point(c.getContactGeomParams()[0][0], c.getContactGeomParams()[0][1]))

for (a,b) in ((id(geom1), geom2), (id(geom2), geom1)):

if not app.collisions.has_key(a):

app.collisions[a] = [Collision(b, cpoints)]

else:

app.collisions[a].append(Collision(b, cpoints))

if self.intersec_push and geom2.coll_props.intersec_push:

for c in contacts:

c.setMode(ode.ContactApprox1 | ode.ContactBounce)

c.setBounce(0.5)

c.setMu(5000)

cjoint = ode.ContactJoint(app.odeworld, cjointgroup, c)

#FIXME: Collision priority stuff doesn't work very well when higher priority object pushes

if self.intersec_pri == geom2.coll_props.intersec_pri:

#Push both objects away from each other

cjoint = ode.ContactJoint(app.odeworld, cjointgroup, c)

cjoint.attach(geom1.getBody(), geom2.getBody())

elif self.intersec_pri > geom2.coll_props.intersec_pri:

#Push the other object, but not this one

cjoint = ode.ContactJoint(app.odeworld, cjointgroup, c)

cjoint.attach(None, geom2.getBody())

else:

#Push this object, not the other one

cjoint = ode.ContactJoint(app.odeworld, cjointgroup, c)