They still work on ODE, and Jolt makes a best-effort attempt to support
them, but they will be removed in a future version.
- Damping should be set explicitly on colliders.
- Tightness and response time will be supported via spring forces, and
also some global settings in newWorld will affect joints too.
- Step count will be added to :update soon. Since the correct value is
dt-dependent in Jolt, a persistent accessor doesn't make sense.
- Sleeping allowed will be an immutable setting in newWorld soon, but
otherwise should be changed per-collider.
refs are cumbersome because they require storing an int and they require
manual cleanup when the object is destroyed.
Instead, we'll go with a pure Lua solution using a table in the
registry. The table has weak keys containing the LÖVR object, and the
values are the userdata. This doesn't require any manual cleanup,
reduces the size of objects by 8 bytes, and is about 25% faster.
The new values come from comments in the official HelloWorld.cpp. After
the changes the any increase of memory consumption is within the
measurement error.