Visibility

I want this game to be impossible to cheat in without access to the server. (By cheating I mean maphacks and things like that. DDoS & co. are entirely other stories.) So I only send informations to the client that they have access to.

This means the server has to calculate, what can each client see, then - using this list - filter all the units and towns, and send them to each clients. Now, since I have to calculate all the tiles that are visible to a client, why would I choose not to send this info to the clients as well? This way, the client code doesn't need to calculate visible tiles.

So this is what I did. After the client receives the list of visible tiles, it sets their color to white (meaning they will be drawn in their original color), and the rest to grey (meaning they will be darker). The only problem so far is that I can't index the tiles by their coordinates (yet), so it takes half a minute to set each tile to the correct color. But at least now it works.

I've made a quick test to check if the visibility rules are calculated correctly on the server. Here is the result:

For the test, I used the Forest, Grass and Mountain tiles. The empty tile is opaque and invisible, so I didn't need to block out visibility with HighMountain tiles. Okay, let's go through all seven tests:

1. You can't look into a group of forest tiles from another group of forest tiles.
2. However, from a mountain tile, you can see other mountain tiles.
3. You can't see forest or mountain tiles from outside.
4. But you can look outside from mountains...
5. ...and from forests.
6. Mountains will block your vision through forests.
7. Forests will block your vision from mountains.

One might argue that why can't one see the other mountains in test 7. - forests shouldn't block the sight from mountains, even if you can't look into them. While this argument is correct, the solution is not trivial - it would require another visibility type, or some height information, or something else.

Or maybe I just shouldn't allow mountains to be visible from other mountains. But playtests will tell. If it is counter-intuitive, I will change it.