tunnel locks and unlocks should operate by changing tunnel collision groups, not by branching after detecting collision

[VoxelStorm Bug Submitter]

Submitted by slowriot from IRC (slowriot on borealis.voxelstorm.com)

[Norgg]

This is a good point and still needs done. Would also allow finer-grained control over what can pass through tunnels in different states.

[Riot]

This would still be nice to resolve; we still have a very inefficient set of messy checks in tunnel::update_state() which is run every tunnel::update() (which is run every tick). Those checks should only run once, when any of the quantities affecting the checks actually change.

Similarly, the colour for the rendering shouldn't be decided by a multiple branch in tunnel::render() every frame, but should be saved and modified only by the above checks.

[Riot]

Removing milestone: Gold (automated comment)