RE: computer-go: Sharing Go modules

["Mark Boon" <tesuji@xxxxxxxxx>]

The color-coding scheme seems to be different for everyone. Before I used 1
for Black and -1 for White so that I do otherColor = -color. However with
any of these schemes you get problems when your code starts to rely on the
particular coding scheme, so I've decided to make constant definitions for
Black, White, Empty etc... and a function (macro in C) invertColor(color)
that does the inversion. Other than that I don't think about it and the
actual values are free to change.

I also have an array with the distance to the edge of each point in it. But
my program has a lot of code that does something like:

 if (board[left(xy)] == board[xy])
	doSomething(left(xy));

and I don't want to have to check all the time for the edge to make sure it
doesn't wrap to the other side. Or worse, go out of bounds. However it
depends a lot on how your program is organised, so for the ManyFaces program
it may be more efficient not to have any boundaries.

And I wouldn't be surprised if after all these years David knows by heart of
all the coordinates where they're on the board :-)

    Mark


> -----Original Message-----
> From: owner-computer-go@xxxxxxxxxxxxxxxxx
> [mailto:owner-computer-go@xxxxxxxxxxxxxxxxx]On Behalf Of David Fotland
> Sent: Thursday, May 17, 2001 4:09 AM
> To: computer-go@xxxxxxxxxxxxxxxxx
> Subject: Re: computer-go: Sharing Go modules
>
>
>
> Many Faces uses 0 for Black, 1 for White, 2 for Empty.
>
> I use single dimension arrays.  0-360 are points (x+y*19), 361 is
> PASS, 362
> is NO_POINT.
>
> I have a separate array edge[363], which contains
> the distance to the nearest edge, that I use for edge detection.
>
> At 08:38 PM 5/16/2001 +0200, you wrote:
> > > I agree it's a good scheme. It's the same one that NNGS uses.
> > > Being able to address the neighbours of point pos as
> > > pos-Vdiff, pos-1, pos+1, and pos+Vdiff is quite a bit more convenient
> > > than dealing with (-1,0), (0,-1), (0,1), (1,0) vectors. Is it
> > > similarly standard to use 0 for EMPTY, 1 for BLACK, 2 for WHITE, and 3
> > > for EDGE ?
> >
> >If BLACK is 0 and WHITE is 1 is easy to write code like
> >
> >procedure DoSomething(p: boardoffset; color: boardcolor);
> >begin
> >   othercolor := 1-color;
> >   ...
> >end;
> >
> >since one rarely want to deal with the colors explicetely. But this is
> >of course a rather minor point. It does not matter for the
> >performance because you only make this transformation once in
> >every procedure.
> >
> >Magnus Persson
>
> David Fotland
>
>