[Freeciv-Dev] Re: (PR#2370) Path finding

[Raimar Falke <rf13@xxxxxxxxxxxxxxxxx>]

On Tue, Feb 18, 2003 at 03:44:16PM +0000, Gregory Berkolaiko wrote:
> Just for the reference,
> <Raimar wrote>
> You get full control over the cost (get_BMC, get_ECOT) and the
> termination condition (get_TB). You may want additionally to do the
> moves_left and turn calculation by yourself. If the *_data stuff and
> the comments are removed:
> 
> struct pf_parameter {
>   int start_x, start_y;
>   void (*update_turn_and_moves_left) (int *, int *, int, int);
>   enum tile_behavior (*get_TB) (int, int, void *);
>   int (*get_ECOT) (int, int, void *);
>   bool(*is_position_dangerous) (int, int, void *);
>   int (*get_COP) (int, int, int, int, void *);
> };
> 
> This is quite minimal. Do you want this?
> <end quote>
> 
> Yes, I agreed to it and I still do.  You forgot to add get_BMC call-back, 
> but otherwise almost everything you need is there.

Looks so.

> The hard problem is to decide what info to pass to get_BMC, though.

The source position of the step, the direction and the data_pointer.

> > This is btw also a flaw in the recent pf*.diff: the use of callbacks
> > for the BMC. _IIRC_ you said that this is an error and you want to fix
> > it.
> 
> I don't think I said it's an error.  Probably I said it could possibly be 
> made faster by turning it into a switch and then new callbacks would be 
> equivalent of adding a new switch to the statement.  I am not 100% sure it 
> would be much faster though, but one can try...

Be aware that the interface from above is inherently slower.

        Raimar

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