// Java Edition Region-Based Structure Placement
regionX = floor(chunkX / spacing)
regionZ = floor(chunkZ / spacing)

// Seed mixing using Java's LCG constants
s = regionX * 341873128712 + regionZ * 132897987541 + worldSeed + salt
s = ((s * s * 6364136223846793005 + 1442695040888963407) >> 17) % (spacing - separation)

// The offset within the region determines the exact chunk
chunkX = regionX * spacing + offsetX
chunkZ = regionZ * spacing + offsetZ
blockPos = (chunkX * 16 + 8, chunkZ * 16 + 8)