Comment by mthoms

This was part of it as well. At least - as I recall - with the early flat (MarioCart 1 inspired) versions I made. But in that case, the closer "terrain" pixels always became multiple on-screen pixels so my lookup table for each of the 360 degree viewpoints contained only a single byte to add to each x and y coordinate, plus a single byte for each length.

Had to keep the memory use down and multiplication was really computationally expensive.