Kirby Super Star: RNG Simulator POC (Hoshi no Kirby Super Deluxe)

kirbysuperstar-rng.c

// Kirby Super Star: RNG Simulator POC

#include <stdio.h>
#include <stdint.h>

static uint16_t seed = 0x7777;

uint8_t random(uint8_t limit) {
  for (int i = 0; i < 11; i++) {
    uint16_t bit = ~(seed ^ (seed >> 1) ^ (seed >> 15)) & 1;
    seed = (seed << 1) | bit;
  }

  uint8_t value = seed & 0xff;
  if (limit != 0) {
    value = (value * limit) >> 8;
  }
  return value;
}

int main(void)
{
  printf("0x%04x\n", seed);
  for (int tick = 0; tick < 10; tick++) {
    random(0);
    printf("0x%04x\n", seed);
  }
  return 0;
}