[mcclim-devel] incremental redisplay and with-first-quadrant-coordinates

[Christophe Rhodes]

Timothy Moore <moore at bricoworks.com> writes:

> I've started to take a look at this. Christophe pointed out that the
> code that checks the stream cursor is only checking the x coordinate;
> apparently a bug, but this change was specifically made during
> Gilbert's rewrite of the compute-difference-set code, so I don't think
> it's right to check both x and y without understanding what he's doing
> there. Gilbert? :)

I don't think that's the bug -- without removing the y-coordinate
check, no output record is ever /moved/ even if it's unchanged apart
from its stream-position.  (I think actually that the x-coordinate
shouldn't be checked either: that way arbitrary translations of
output-records would be possible.  I don't know why that wasn't
implemented at the time...)

Cheers,

Christophe