Modern puyo games' queue generator (Confirmed on Puyo Puyo Champions and Puyo Puyo Tetris 2)

puyo_queue_generator.cpp

std::vector<Cell::Type> get_queue(u32 seed)
{
    // Modern puyo games' internal random number generator
    auto rng = [&] () -> u32 {
        seed = (seed * u32(0x5D588B65) + u32(0x269EC3)) & u32(0xFFFFFFFF);
        return seed;
    };

    // Choose which colors to use
    // We only care about the number of time that the rng() function is called, since the color orientation isn't important
    // TLDR: Don't care about this, it's just here
    for (i32 i = 0; i < 5; ++i) {
        rng();
    }

    // Initialize queue
    // There are 3 modes of queue: 3 colors, 4 colors and 5 colors
    u8 queue[3][256] = { 0 };

    for (i32 mode = 0; mode < 3; ++mode) {
        for (i32 i = 0; i < 256; ++i) {
            queue[mode][i] = i % (mode + 3);
        }
    }

    // Shuffle the queues (all 3 modes)
    for (i32 mode = 0; mode < 3; ++mode) {
        // 1st shuffle
        for (i32 col = 0; col < 15; ++col) {
            for (i32 i = 0; i < 8; ++i) {
                i32 n1 = (rng() >> 28) + col * 16;
                i32 n2 = (rng() >> 28) + (col + 1) * 16;

                std::swap(queue[mode][n1], queue[mode][n2]);
            }
        }

        // 2nd shuffle
        for (i32 col = 0; col < 7; ++col) {
            for (i32 i = 0; i < 16; ++i) {
                i32 n1 = (rng() >> 27) + col * 32;
                i32 n2 = (rng() >> 27) + (col + 1) * 32;

                std::swap(queue[mode][n1], queue[mode][n2]);
            }
        }

        // 3rd shuffle
        for (i32 col = 0; col < 3; ++col) {
            for (i32 i = 0; i < 32; ++i) {
                i32 n1 = (rng() >> 26) + col * 64;
                i32 n2 = (rng() >> 26) + (col + 1) * 64;

                std::swap(queue[mode][n1], queue[mode][n2]);
            }
        }
    }

    // Copy the first 4 puyos (or the first 2 pairs) of the 3-color queue to the 4-color queue and 5-color queue
    // This will ensure that the first 2 pairs of the puyo queue always contain only 3 colors
    for (i32 i = 0; i < 4; ++i) {
        queue[1][i] = queue[0][i];
        queue[2][i] = queue[0][i];
    }

    // Since only the 4-color queue is used in battles, we will only return it
    std::vector<Cell::Type> result;

    for (i32 i = 0; i < 256; ++i) {
        result.push_back(Cell::Type(queue[1][i]));
    }

    return result;
};