This is not likely to have a very strong effect, but it's the best we
can do short of writing an entirely new chess engine. The HoiChess
engine seems to be notably easier than other engines, so currently that
seems like the best choice to distribute with GNOME Chess.
Fixes#18, at least sort of.
We'll now search for AI profiles in:
* ~/.config/gnome-chess/engines.conf (first)
* /etc/gnome-chess/engines.conf
I'm torn as to whether to continue reading /etc/chess-engines.conf. I
think it'd be best to ignore it -- if users modified it manually to add
an engine, they will notice that the engine has disappeared. They're not
likely to notice that they're not getting the important GNUChess
improvements I'm hoping to land soon....
This isn't really a fix, as every engine that limits depth to 2
(including Glaurung) will just search to 2 if told to use depth 1. But
it's nice to keep the config file consistent with reality.
I'm really excited about how easy HoiChess is to beat. It must not be
using any extensions/quiescence at all. However this does make it
extremely unrealistic to play against at depth 1.
I was disappointed when I discovered that most engines did not respect
the depth command. But it turns out that this is a GNUChess (and
Phalanx)-specific extension. Everyone else uses sd for the same
purpose. This means that we get to provide meaningful difficulties for
these engines after all. Yay!
* Allow engine arguments to depend on difficulty
* Improve difficulty levels for many engines... but not much
* Stockfish and then Phalanx are now preferred over GNUChess
Unfortunately, all of these engines are too hard for our needs.
Some of these engines seem to be Windows-only; others are proprietary;
and others don't want to compile anymore. I've left these alone since
there's not much reason to remove them in case you do manage to get one
working. But they won't be getting difficulty levels.
https://bugzilla.gnome.org/show_bug.cgi?id=475535
