Contacts

Reads ENTER, STAY, and EXIT events produced by the physics simulation.

Native contact callbacks are copied into a bounded thread-safe queue. jolt_update() drains that queue into a world event list and into per-body lists for the most recently processed frame.

Event constants#

High-Level API#

var world_events = jolt_get_collisions();
var body_events = body.get_collisions();
var dropped = jolt_get_dropped_collision_count();

World event fields#

Per-body event fields#

For body_b, the wrapper negates the native normal so each body's list has the opposite orientation. A world event retains the native body_a/body_b ordering.

Queue behaviour and limits#

• The native queue holds at most 4096 events.
• When full, the oldest event is removed and the dropped counter increases.
• The active-contact map is keyed by both BodyIDs and both SubShapeIDs, so compounds can produce distinct sub-shape pairs.
• EXIT reuses the last stored contact position and normal and sets penetration_depth to 0.
• Only the first available manifold point pair is exposed by the public event.

Typical loop#

var events = jolt_get_collisions();
for (var i = 0; i < array_length(events); ++i) {
    var event = events[i];
    switch (event.type) {
        case JOLT_COLLISION_ENTER: break;
        case JOLT_COLLISION_STAY:  break;
        case JOLT_COLLISION_EXIT:  break;
    }
}

Low-Level / Advanced API#

jolt_world_collision_next(world)
jolt_world_collision_get_dropped_count(world)
jolt_world_collision_clear(world)

collision_next() pops one copied event and returns undefined when empty. collision_clear() removes queued events and resets the dropped counter; the managed runtime normally drains automatically.

Verified operation contracts#

These contracts distinguish units, return values, errors and lifetime according to the current implementation. Check results: false, 0 and undefined can mean different things for different methods.