The Well1024 random number generator in C#

Well.cs

namespace Utils
{
    class Well
    {
        private uint seed;
        private uint state_n;
        private uint[] state;

        private uint mat3pos(int t, uint v)
        {
            return v ^ (v >> t);
        }

        private uint mat3neg(int t, uint v)
        {
            return v ^ (v << (-t));
        }

        public Well(uint seed)
        {
            this.seed = seed;
            state_n = 0;
            state = new uint[32];
            state[0] = seed & 0xffffffffu;
            for (int i = 1; i < 32; ++i)
            {
                state[i] = (69069u * state[i - 1]) & 0xffffffffu;
            }
        }

        public double sample()
        {
            uint z1 = state[state_n]^mat3pos(8, state[(state_n + 3u) & 0x0000001fu]);
            uint z2 = mat3neg(-19, state[(state_n + 24u) & 0x0000001fu])^(mat3neg(-14, state[(state_n + 10u) & 0x0000001fu]));
            state[state_n] = z1 ^ z2;
            state[((state_n + 31u) & 0x0000001fu)] = (mat3neg(-11, state[(state_n + 31u) & 0x0000001fu])) ^ mat3neg(-7, z1) ^ mat3neg(-13, z2);
            state_n = (state_n + 31u) & 0x0000001fu;
            return state[state_n] * 2.32830643653869628906e-10;
        }
    }
}