PSX fixed point maths psx-sdk-rs psx::math f16: 16-bit, signed, 7-bit integral, 8-bit fractional -128 to 127 scale value: 2**8 = 256 vs. PSX tutorial: 32-bit, signed, 19-bit integral, 12-bit fractional -524288 to 524287 scale value: 2**12 = 4096