Apple's Chess 2.0 Source Code Available

Petrochard writes "For all of you programmers who are big chess fans, check out Apple's release of Chess 2.0's source code. It would be cool if somebody could make a Simpson's Chess mod." Chess is based on sjeng (logic) and glChess (interface).

Comments

sjeng author wrote extreme vorbis encoder

[ubiquitin]

The gentleman who wrote sjeng also wrote prototype Vorbis 1.0 encoder that can go down to bitrates of 4kbps that he claims can give a listenable stereo stream. IMHO that's bigger news than source to Chess.app 2.0.

scary

[Tumbleweed]

I think I'd be too intimidated to play chess against "the world's most powerful computer." Gosh. :)

Joke aside, I'm eagerly awaiting the 970FX PowerMac, and VERY eagerly awaiting the 3gHz (980?) machines this summer. Ohhh yeahhh...

Re:Thats Nice of Them

[Otter]

It's the bundled OS X chess game. You didn't think Mac users played _Solitaire_, did you?

Is this something new ?

[javaxman]

While very cool, I have to ask if this is something new.

The reason I wonder is that when I click on the "About Chess" menu item in Chess 2.0 as installed on OS X 10.3, I notice that in the lower right hand corner of the About window there is a button labeled "Download Source Code...". The button opens this page Apple - Public Source - Miscellaneous.

So, while still cool, this is not likely to be "news". I do appreciate the pointer, though. It'll be nice to check out for programming ideas, as I'm getting back into Objective-C programming again.

For folks wanting Simpsons mods and other simple image changes, though, you probably don't need the source for that, you just need to realize that the images are in the .app package... changing those really shouldn't require a recompile, should it?

It can be done...

[Crash Culligan]

I think it'd be sweet if somebody made the application so that the board just floated over the other windows, not inside of it's own window. I thought that's how it was supposed to be originally, but unfortunately I was wrong.

One of the cornerstones of the current Cocoa-y way of doing things is that the front-end and back-end are separate beasts.

Don't like the back-end? It's possible to build the app to use a program other than sjeng as its brain. It's just a matter of building with a new shell tool (and a little glue so the front-end knows how to use it).

Don't like the front end? It's also possible to build a new wrapper app for sjeng that looks however you want it to. Use the source for the existing Chess program as a template for sjeng, and then go completely nuts. Screw reskinning, design a completely different and abstract chess game!

But the windowless interface might be confusing to some users...

55 W. P - e5
55 B. P x P
56 W. N x P
56 B. B x System Preferences ?
57 W. BitTorrent - A4 !!
Kernel Panic in 4 moves

Re:Simpsons been done to death

[Entropy2016]

How about this setup?

Pawn = The common zealous user, because once you go Mac you never go back. Also, there are those rare ones that go all the way to make the next killer app and become Queen-rich.

Knight = Apple's engineers, because of the new & innovative ways in which they move...

Bishop = User-group leaders, because someone has to shepherd the flock...

Rook = Apple-lawyers, because everyone fears being pinned by the long-arm of the law...

Queen = Woz, because that one piece has serious some skills...

King = Jobs, because as soon as you think you've caught-up to him, he uses his reality-distortion-field to castle in a new direction. Also, no matter how little is left on the board, you can't quite nail him without a lawyer.

Transparent window?

[CODiNE]

Could somebody figure out how to re-enable the transparent effect that was in the Panther betas? It was a preference before, but now it's gone. In case some haven't seen it before, the board was floating with no background window. I don't remember if the window was transparent or actually able to be clicked-through, but it was very cool. :)

I can't figure it out myself since I'm not a coder, but I've narrowed it down to MBCFloatingBoardWindow... no idea what to do with it tho. Any pointers? :)

Re:Transparent window?

[TomorrowPlusX]

Well, I downloaded the source and examined it and I can tell you how to turn the transparent window back on.

Comment out lines 741 through 744 of MBCController.mm -- funny, you've gotta love Objective-C++ -- half my work's in it too. You listening apple? Hire me ;)

Specifically:

[[fFloatingMenuItem menu] removeItem:fFloatingMenuItem];
[[fFloatingView window] release];
fFloatingMenuItem = nil;
fFloatingView = nil;

I found these pretty quickly -- particularly since the menu item *is* in the nib file, that meant I could just run a search for [someMenu removeItem: ] and whammo, there it was. You can thank me later.

Above those lines is a call to getenv() looking up the string "MBC_DEBUG" so I gather you could simply set the parameter in your .profile, but I'm not certain how those parameters affect Gui apps. Quick run to the terminal and running Chess.app from there had no effect, but then, perhaps I'd have to log out and back in.

Anyway, the above instructions will return the command-F floating window effect.

Try to use it... then you'll understand why apple took it out. It's sad, because from a performance standpoint it's *fine*, the trouble is there's no way to drag or resize the window!

Transparent Window Hack

[kuwan]

After taking a look at the source I found out that the floating window can be activated without making any modifications to the application. Here's how to enable the transparent window:

Open Terminal.app and set MBC_DEBUG as an environment variable to 16:

With bash:

set MBC_DEBUG=16

with tcsh:

setenv MBC_DEBUG 16

Now, open Chess.app from the Terminal:

open /Applications/Chess.app/

There will be a new menu item (Floating Board) under the "Game" menu. Selecting this menu item will toggle the floating board on and off.

There seems to be a bug with the mouse behavior (I can't move any pieces) and I assume this is why this feature was removed. I found that you can get around this bug by doing the following:

Start a game with the normal window.
Play at least one move.
Switch to the floating board.
Select "Take Back Move" from the "Moves" window.
You should now be able to move the pieces as normal.

Re:The Licensce

[geoffspear]

Thanks! I was worried that opensource.apple.com was going to be slashdotted.