[Freeciv-Dev] Re: Caravans

[Mathias Broxvall <matbr@xxxxxxxxxx>]

>It would be nice to implement Civ2-style trade-routes, controlled by a ruleset 
file.  I've started thinking about this, but so far only have a tentative 
example of a "commodities.ruleset" file (see attachment).

How about specifying tileset prerequicites and weights to the commodities
available at a specific city. Also techonologies could be needed as
prerequicites. For example:

[commodity_copper]
commodity_name          = _("Copper")
immediate_gold          = 100
immediate_science       = 100
trade_bonus             = 100
weight                  = 100
terrain                 = "mountains"
tech                    = metalworking  ; Yeah, I know - poor example...

[commodity_machinetools]
commodity_name          = _("Machine Tools")
immediate_gold          = 100
immediate_science       = 0
trade_bonus             = 100
weight                  = 50
terrain                 = "none"
tech                    = industrialism

[commodity_hides]
commodity_name          = _("Hides")
immediate_gold          = 100
immediate_science       = 0
trade_bonus             = 50
weight                  = 1
terrain                 = "none"
tech                    = "none"

The purpose of the above commodities is that atleast one mountain square
is needed to produce copper as soon as the player has the metalworking
advance. (Was that tech in the old board game perhaps?)
Machinetools can be manufactured as soon as the player has industrism
and hides is a default commodity any city can produce. For instance, if
there is a limit of one commodity per city then mountain cities should
always produce copper, other high tech cities always tools and hides would
only be a default commodity for the poor cities.

As a matter of the maximum number of trade routes *from* a city one could either
set a fixed number (three?), let it grow with city size (half city population?)
or let it be as many as is specified in the commodities section and is
applicable to the city in question (limited by what terrain tiles are near the
city and the owner's technology). 

Also perhaps it would be an idea with a "minimum distance" between commodities
so that rare commodities don't occur in cities next to each other? (Could be
hairy to implement tough...) or perhaps it's good to have a uniform distribution
of goods so that part of the continents can be regarded as "gold belts",
"vine districts" etc.. I.e. player A has lots of cities producing Wine
but none producing Gold, player B the opposite. Therefore they have to
trade between themselves to trade optimally

Perhaps some similar arangement can be made for the demands of the cities?
any comment? Hope some ideas where usefull for you...

/ Mathias