John Carmack (@ID_AA_Carmack) at 2021-06-16 18:34:42 UTC: I mentioned the "mirror trick" in my last App Review, but it just struck me to apply it to side scrolling games, so I flipped the texcoords and left/right button bits in my AI stage harness, and it is striking how different a level you have seen a hundred times is when flipped! https://t.co/JJgshHOnyh — Link to this Tweet