Physics calls
ay2d_has_physics
int32_t ay2d_has_physics(const ay2d_model *m);
1 when the model has a rig. Thread: any.
ay2d_set_physics
ay2d_status ay2d_set_physics(ay2d_model *m, int32_t on);
1 runs the rig on each update, 0 holds it. Thread: frame.
ay2d_set_wind
ay2d_status ay2d_set_wind(ay2d_model *m, float x, float y);
A steady push on every pendulum, in the units gravity has. Thread: frame.
ay2d_reset_physics
ay2d_status ay2d_reset_physics(ay2d_model *m);
Every pendulum back at rest. Thread: frame.