The original algorithm pays intermediate legs in feeder systems based
on the start and end stations of that particular leg.
This tends to result in large negative payments on the final leg for
journeys with many feeder legs, as the overall feeder payment increases
with the number of legs, and the final leg is penalised for discrepancies
between the previous leg payments and the actual payment for delivery
from the source to the destination.
The feeder share setting is a partial mitigation, however it is difficult
to tune as a suitable value depends on the number of legs and the network
topology, which are often not the same for all vehicles.
The new incremental algorithm pays the cargo payment from the source
station to the end station of the current leg, minus any previous
transfer feeder payments for each leg.
This prevents unbounded increase of feeder payments and therefore avoids
the issue of excessive negative payments on the final leg.
Feeder payments may be negative, e.g. in the case of poorly performing
or highly indirect legs. This is better than penalising the final leg.
This mode reduces the need to tune the feeder shares setting to the
current network.
The feeder share setting applies in the existing way.
This switch has been a pain for years. Often disabling broke
compilation, as no developer compiles OpenTTD without, neither do
any of our official binaries.
Additionaly, it has grown so hugely in our codebase, that it
clearly shows that the current solution was a poor one. 350+
instances of "#ifdef ENABLE_NETWORK" were in the code, of which
only ~30 in the networking code itself. The rest were all around
the code to do the right thing, from GUI to NewGRF.
A more proper solution would be to stub all the functions, and
make sure the rest of the code can simply assume network is
available. This was also partially done, and most variables were
correct if networking was disabled. Despite that, often the #ifdefs
were still used.
With the recent removal of DOS, there is also no platform anymore
which we support where networking isn't working out-of-the-box.
All in all, it is time to remove the ENABLE_NETWORK switch. No
replacement is planned, but if you feel we really need this option,
we welcome any Pull Request which implements this in a way that
doesn't crawl through the code like this diff shows we used to.
This change is a controlled by a game setting, located under Environment ->
Industries which allows toggling the behaviour. It defaults to enabled.
"Company stations can serve industries with attached neutral stations"
When enabled, industries with attached neutral station (such as Oil Rigs) may
also be served by company-owned stations built nearby. This is the traditional
behaviour.
When disabled, these industries may only be served by their neutral station.
Any nearby company-owned stations won't be able to serve them, nor will the
neutral station serve anything else other than the industry.
Pavel Stupnikov