advance_prng.mcfunction

# Advance the given PRNG seed, optionally using salt to diverge into a new stream.

# multiplier = 1103515245
# increment = 12345
# truncate = 16

# start with the seed
scoreboard players operation $result foo._out = $seed foo._in

# mutate the seed by multiplying by the salt
# (a value of 1 will have no effect and will produce the same result as standard LCG)
scoreboard players operation $result foo._out *= $salt foo._in

# multiply by the constant multiplier
scoreboard players operation $result foo._out *= $prng.multiplier foo._const

# add the constant increment
scoreboard players operation $result foo._out += $prng.increment foo._const

# module is done naturally by scoreboard overflow

# drop a few lower bits to improve randomness
scoreboard players operation $result foo._out /= $prng.truncate foo._const