ref: 6acddeda91c85d2bbf27715330e183ab9d3acb2b dir: /sys/src/games/swar/accel.h/
512, 0, 473, 196, 362, 362, 196, 473, 0, 512, -196, 473, -362, 362, -473, 196, -512, 0, -473, -196, -362, -362, -196, -473, 0, -512, 196, -473, 362, -362, 473, -196,