[Freeciv-Dev] Re: another vision range patch (PR#4674)

["Gregory Berkolaiko" <Gregory.Berkolaiko@xxxxxxxxxxxx>]

After a quick glance at get_unit_vision_range:

1. The function is wrong, you must check for the S_FORTRESS at the 
location.

2. It is at the server, which means the human auto-explorer will be
cheating: knowing where the watchtowers are in the unknown.


On Sun, 27 Jul 2003, Jason Short wrote:

> 
> This much larger patch:
> 
>    - Adds get_unit_vision_range and get_unit_vision_range_at.
>    - Removes unit_profits_of_watchtower and get_watchtower_vision.
>    - Rewrites code to use the new functions.
>    - Replaces old unit_type.vision_range calculations.
>    - Fixes several unrelated bugs.
> 
> The unrelated bugs actually look pretty severe.  For instance when a 
> watchtower is pillaged the server iterates over all units on the tile to 
> update their vision.  However it doesn't update the vision for the 
> unit's owner's but rather for the pillaging unit's owner.  In the rare 
> case where these differ the results would likely be disasterous.  This 
> same type of bug occurs in several places.
> 
> Nonetheless the correctness of this patch is not obvious and it should 
> probably be broken up and the changes made piece-by-piece.  I think 
> vision_range-2.diff is a good start.
> 
> An additional (dis)advantage is that the only assumption left is that 
> only for fortresses will watchtower vision apply.  Other arbitrary 
> assumptions (like is_ground_unit()) are removed - giving more correct 
> code but also some spurious fog/unfogs.
> 
> Greg, Rafal?
> 
> jason
> 
> 
> 
>