Re: [Freeciv-Dev] Idea for 2.0

[Jules Bean <jmlb2@xxxxxxxxxxxxxxxx>]

Greg Wooledge wrote:
> 
> 
> I don't know whether anyone's currently working on fog of war, but I'll
> offer my thoughts.
> 
> The only good way to get all of the above working correctly is to enforce
> it at the server.  If the client is told all of the units in a stack, it
> could be hacked by the player to give information the player should not
> have.  (Under Civ2 rules, you can determine that an enemy boat is carrying
> one or more passengers (or shares the square with another boat) by the plus
> sign, but you can't know what those passengers are until you attack and win.
> But if the server tells the client what all the units on the boat are, the
> player has information (s)he shouldn't have.)
> 
> Fog of war would work similarly.  Tile update information cannot be sent
> to the player unless the player should get that info -- if the enforcement
> is at the client, the client could be hacked to do what it currently does
> (display all tile updates).  Or people could just run old clients....
> 
> The same goes for invisible units.  If you don't want the player to know
> where enemy subs are, don't send the information!
> 
> So, every way I look at it, the server needs to be modified.  It has to
> be more selective about what information it sends to the player.
> 

Absolutely.  The server should definitely only send what the player is
supposed to know.

Cosmetically, I'd like to see the client displaying a visible 'fog' over
'known but not currently seen' tiles, so we know what we know, IYSWIM.

> But for fog of war specifically, there's another factor.  The player
> should be able to see a tile (s)he has already explored, even if it's
> not updated.  Thus, the client has to keep a copy of the last "version"
> of a tile sent by the server.  That's all fine, and trivial... until you
> get to the saved game.  When a game is loaded, and a client reconnects,
> it should get a copy of the map just like the one it had when the game
> was saved.  Thus, the server must also know what the client sees -- which
> means the server must keep a record of every client's "view" of the map.

I disagree.  I think that at save game time, the server should ask the
client 'is there any data you want to save?'.  And the client should
send back its map.  I think it's rather complicated to have the server
remember what each client thinks it can see - and additionally it seems
less elegant.  In fact, the server could treat the data the client sends
back as opaque, and just save it - so clients could be extended to keep
more information (statistics, say) and the server would just stick it
into the savegame.

Jules

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|  Julian Bean   | jmlb2@xxxxxxxxxxxxxxxx        |  TW9 2TF *UK*       |
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