[eru]

> - 2px wide would have been quite wide, and 1px would have been off centre.

Off-centre of your monitor, but not necessarily off-centre as far as the game is concerned: it would be trivial to shift everything one (or half?) a pixel to the upper left. Ie so that your shooting direction perfectly aligns with the crosshair. You could do that for any crosshair position.

Even cross-hairs that are off-screen.

[lloeki]

To be fair, I don't think it really mattered, I mean there was so much hackery going on (either because of oversight or as performance tricks)† than a pixel off isn't really a problem.

† such as https://www.youtube.com/watch?v=4gNYTqn3qRc https://www.youtube.com/watch?v=zfY96tAqmdI