BRIGHT
fc = BUP * uvert + BDOWN * dvert + BRIGHT * rhori;
BLEFT * lhori + BRIGHT * rhori +
cpn->pos != TBL_CELL_DOWN ? BRIGHT * hw : 0), 1);
BRIGHT * rw + BUP * uw + BDOWN * dw, 1);
#define BHORIZ (BLEFT + BRIGHT)