[Freeciv-Dev] (PR#10722) Excess amount of unfavorable terrain generated by current mapgen code

["Mike Jing" <miky40@xxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=10722 >

The new mapgen code is generating a lot more "unfavorable" terrain compared 
to earlier versions, as can be seen in the following table of the amount of 
each terrain type as a percentage of total landmass (all using default 
parameters):

Terrain Type                1.14.2                CVS Oct. 24, 2004

Grassland                    ~33%                      ~10%
Plains                       ~33%                      ~10%
Forest                       ~ 6%                      ~24%
Hills                        ~ 6%                      ~15%
Mountains                    ~ 2%                      ~ 9%
Desert                       ~ 2%                      ~ 7%
Jungle                       ~ 1%                      ~ 4%
Swamp                        ~ 1%                      ~ 4%
Tundra                       ~ 3%                      ~ 3%
Arctic                       ~14%                      ~15%


Most striking is the decrease of the amount of Grassland/Plains, from around 
2/3 down to only 1/5.  In contrast, all other terrain types, except Arctic 
and Tundra, increased by a factor of about 4.  This makes choosing a proper 
city site extremely difficult and simply upsets the game way too much.  To 
make matters worse, this cannot be fully remedied by adjusting the mapgen 
parameters, which were reduced to only three: temperature, steepness, and 
wetness.  A steepness of 0 to 5 makes the amount of hills and mountains more 
or less acceptable, but the total amount of Desert, Jungle, and Swamp 
combined is basically invariant with respect to changes in wetness.  
Lowering the temperature produces more Arctic and Tundra, but does not 
reduce the amount of Desert and Swamp far enough.  In short, the current 
mapgen code is broken and has to be fixed before 2.0 can be released.

Mike Jing