| 1 | #include "random/seadRandom.h" |
|---|---|
| 2 | #include "time/seadTickTime.h" |
| 3 | |
| 4 | namespace sead |
| 5 | { |
| 6 | void Random::init() |
| 7 | { |
| 8 | TickTime now; |
| 9 | init(seed: static_cast<u32>(now.toTicks())); |
| 10 | } |
| 11 | |
| 12 | void Random::init(u32 seed) |
| 13 | { |
| 14 | const u32 mt_constant = 0x6C078965; |
| 15 | mX = mt_constant * (seed ^ (seed >> 30u)) + 1; |
| 16 | mY = mt_constant * (mX ^ (mX >> 30u)) + 2; |
| 17 | mZ = mt_constant * (mY ^ (mY >> 30u)) + 3; |
| 18 | mW = mt_constant * (mZ ^ (mZ >> 30u)) + 4; |
| 19 | } |
| 20 | |
| 21 | void Random::init(u32 seed_x, u32 seed_y, u32 seed_z, u32 seed_w) |
| 22 | { |
| 23 | if ((seed_x | seed_y | seed_z | seed_w) == 0) |
| 24 | { |
| 25 | SEAD_ASSERT_MSG(false, "seeds must not be all zero."); |
| 26 | seed_w = 0x48077044; |
| 27 | seed_z = 0x714ACB41; |
| 28 | seed_y = 0x6C078967; |
| 29 | seed_x = 1; |
| 30 | } |
| 31 | mX = seed_x; |
| 32 | mY = seed_y; |
| 33 | mZ = seed_z; |
| 34 | mW = seed_w; |
| 35 | } |
| 36 | |
| 37 | u32 Random::getU32() |
| 38 | { |
| 39 | u32 x = mX ^ (mX << 11u); |
| 40 | mX = mY; |
| 41 | mY = mZ; |
| 42 | mZ = mW; |
| 43 | mW = mW ^ (mW >> 19u) ^ x ^ (x >> 8u); |
| 44 | return mW; |
| 45 | } |
| 46 | |
| 47 | u64 Random::getU64() |
| 48 | { |
| 49 | return u64(getU32()) << 32u | getU32(); |
| 50 | } |
| 51 | |
| 52 | void Random::getContext(u32* x, u32* y, u32* z, u32* w) const |
| 53 | { |
| 54 | *x = mX; |
| 55 | *y = mY; |
| 56 | *z = mZ; |
| 57 | *w = mW; |
| 58 | } |
| 59 | } // namespace sead |
| 60 |