[Freeciv-Dev] Re: [RFC] Path finding interface #9

[Raimar Falke <rf13@xxxxxxxxxxxxxxxxx>]

On Wed, May 29, 2002 at 05:11:43PM +0100, Gregory Berkolaiko wrote:
> On Wed, 29 May 2002, Raimar Falke wrote:
> 
> > Ok. And can I say that I want to trade saved turn for x "danger
> > points"? The difference where I arrive with n turns and 5 points left
> > is different to arriving in n-1 turns and 1 point left. It is more
> > different than the two move points.
> 
> I am not sure how the "danger points" come into the second part of the 
> question...
> 
> Can't you just wait in the final position for one turn, so you'll 
> effectively be there in n turns with 6 points left?

There there 3 different metrics to measure the "goodness" of a path:
 - BMC
 - extra cost (danger and pseudo BMC for unknown tiles)
 - time (turns and moves_left)
and there is is_safe_tile but this just remove some paths in a kind of
pre-processing step.

So you can judge a path just by its BMC or just by its time. So in
general you may want to do something like:
 goodness = BMC*factor1+extra_cost*factor2+turns*factor3+moves_left*factor4

So if we assume that factor1 is 0 you see that you can balance a
higher turns value with a smaller extra_cost value. Depending on the
values you can say that 1 turns can be balanced by n extra_cost
(points).

This model is a lot clearer than the previous one. So I have attached
a 10th version of the interface. You can now specify a function which
does calculate the "goodness" of a path. This also allows you to make
a path with turns=n, moves_left=0 equivalent to turns=n+1,moves_left=6
which is needed for settlers.

The patch also made the definition of is_position_safe a lot
clearer. It is also renamed.

        Raimar

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 email: rf13@xxxxxxxxxxxxxxxxx
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path_finding10.h
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