[Freeciv-Dev] Re: [RFC] Path finding interface #6

[Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx>]

On Mon, Apr 08, 2002 at 09:08:43AM +0200, Raimar Falke wrote:

All new version 6. Changes to version 4:
 - make last_position a macro
 - remove _from_map
 - add pf_construct_path
 - change signature of pf_get_next_position

Gregory: After some more thinking I don't like the
get_zoc_permission. Reason: It just doesn't work. AFAI read the code
you have to know the source position to know if you can step on a
target tile. So while we may add a
  bool (*get_zoc_permission)(int src_x, int src_y, int dest_x, int dest_y, void 
*user_data)

the result may not be cachable and also I don't see a reason to allow
customization of the process. So I think that the path finding core
should do this internally. This may also allow some caching like (per
internal tile) a

 bool is_my_zoc=map_get_city(x, y)||map_get_terrain(x, y) == 
T_OCEAN||is_my_zoc(unit_owner, x, y);
 bool allied_tile=is_allied_unit_tile(map_get_tile(x, y), unit_owner);

This together with a global
 bool zoc_used = (move_type == LAND_MOVING) && doesn't have IGZOC flag

allows us to code the test as simple as
 zoc_ok = zoc_used || internal_src_tile.is_my_zoc || 
internal_dest_tile.is_my_zoc || internal_dest_tile.allied_tile

        Raimar, today "The Defender Of The Performance"

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path_finding6.h
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