Change to no_routing_over_overcrowded behaviour

[TurfIt]

When using the no_routing_over_overcrowded setting, factories such as pak64's Sawyer which consume and produce the same good category can easily deadlock. I propose changing the behaviour so that the overcrowding status of the destination station is ignored. The avoid_overcrowding setting already works this way.

Also, blocking transfers of all goods in a category when only one is overcrowded doesn't make much sense IMHO. Maybe if the halts capacity applied to the category and not the individual goods... So also proposed is changing the overcrowding status to be per good rather than per category.

Patch attached. Thoughts?

[Ters]

I propose changing the behaviour so that the overcrowding status of the destination station is ignored.

Makes perfect sense. Especially for passengers, that will realistically just leave the station immediately (even if they have to force a path). For goods, Simutrans simply treats it the same way as passengers anyway.

Also, blocking transfers of all goods in a category when only one is overcrowded doesn't make much sense IMHO. Maybe if the halts capacity applied to the category and not the individual goods... So also proposed is changing the overcrowding status to be per good rather than per category.

Is the limit which stops producers from delivering cargo to the initial station goods specific? I can't tell for sure if that's what your saying in the second sentence. It only makes sense that the same rules apply to each transfer, as for the initial station. I don't have much opinion on whether this should be per goods or per category, as I rarely have conflicts on category level (at the origin station, and I think also on my few hubs even if I had no_routing_over_overcrowded on). It has also been argued that capacity should be measured against the sum of all goods, but this will likely require capacity adjustments in all pak sets.

[Dwachs]

The second change makes sense imho.

Just for clarification: The only place I can think of, where in the route searching overcrowded destinations are blocked, is the check (simhalt.cc:1419)

Code Select Expand


if(  overcrowded_nodes == open_list.get_count()  ) {
// all unexplored routes go over overcrowded stations
return ROUTE_OVERCROWDED;
}

So it terminates early if all nodes in the open list are overcrowded including destinations, which made a big difference on large overcrowded maps. Then thhe point of your change is to prevent that   overcrowded destinations with not overcrowded route are counted towards overcrowded_nodes?  This is fine imho, too.

[Dwachs]

This could be committed imho.

[DrSuperGood]

I agree that destinations should be ignored. Overcrowding does not matter at destination since the goods depart on arrival to their final destination.

[TurfIt]

committed r7628.

Is the limit which stops producers from delivering cargo to the initial station goods specific?

Yes.

It has also been argued that capacity should be measured against the sum of all goods, but this will likely require capacity adjustments in all pak sets.

Something to try someday as an option. The existing capacities are likely fine; Would provide some incentive to use the station extension buildings which are rarely seen...