#define _gs(x,y,z,w) ((x) | ((y) << 2) | ((z) << 4) | ((w) << 6))

enum shuffle : unsigned
{
    xxxx = _gs(0, 0, 0, 0),
    xxxy = _gs(0, 0, 0, 1),
    xxxz = _gs(0, 0, 0, 2),
    xxxw = _gs(0, 0, 0, 3),
    xxyx = _gs(0, 0, 1, 0),
    xxyy = _gs(0, 0, 1, 1),
    xxyz = _gs(0, 0, 1, 2),
    xxyw = _gs(0, 0, 1, 3),
    xxzx = _gs(0, 0, 2, 0),
    xxzy = _gs(0, 0, 2, 1),
    xxzz = _gs(0, 0, 2, 2),
    xxzw = _gs(0, 0, 2, 3),
    xxwx = _gs(0, 0, 3, 0),
    xxwy = _gs(0, 0, 3, 1),
    xxwz = _gs(0, 0, 3, 2),
    xxww = _gs(0, 0, 3, 3),

    xyxx = _gs(0, 1, 0, 0),
    xyxy = _gs(0, 1, 0, 1),
    xyxz = _gs(0, 1, 0, 2),
    xyxw = _gs(0, 1, 0, 3),
    xyyx = _gs(0, 1, 1, 0),
    xyyy = _gs(0, 1, 1, 1),
    xyyz = _gs(0, 1, 1, 2),
    xyyw = _gs(0, 1, 1, 3),
    xyzx = _gs(0, 1, 2, 0),
    xyzy = _gs(0, 1, 2, 1),
    xyzz = _gs(0, 1, 2, 2),
    xyzw = _gs(0, 1, 2, 3),
    xywx = _gs(0, 1, 3, 0),
    xywy = _gs(0, 1, 3, 1),
    xywz = _gs(0, 1, 3, 2),
    xyww = _gs(0, 1, 3, 3),

    xzxx = _gs(0, 2, 0, 0),
    xzxy = _gs(0, 2, 0, 1),
    xzxz = _gs(0, 2, 0, 2),
    xzxw = _gs(0, 2, 0, 3),
    xzyx = _gs(0, 2, 1, 0),
    xzyy = _gs(0, 2, 1, 1),
    xzyz = _gs(0, 2, 1, 2),
    xzyw = _gs(0, 2, 1, 3),
    xzzx = _gs(0, 2, 2, 0),
    xzzy = _gs(0, 2, 2, 1),
    xzzz = _gs(0, 2, 2, 2),
    xzzw = _gs(0, 2, 2, 3),
    xzwx = _gs(0, 2, 3, 0),
    xzwy = _gs(0, 2, 3, 1),
    xzwz = _gs(0, 2, 3, 2),
    xzww = _gs(0, 2, 3, 3),

    xwxx = _gs(0, 3, 0, 0),
    xwxy = _gs(0, 3, 0, 1),
    xwxz = _gs(0, 3, 0, 2),
    xwxw = _gs(0, 3, 0, 3),
    xwyx = _gs(0, 3, 1, 0),
    xwyy = _gs(0, 3, 1, 1),
    xwyz = _gs(0, 3, 1, 2),
    xwyw = _gs(0, 3, 1, 3),
    xwzx = _gs(0, 3, 2, 0),
    xwzy = _gs(0, 3, 2, 1),
    xwzz = _gs(0, 3, 2, 2),
    xwzw = _gs(0, 3, 2, 3),
    xwwx = _gs(0, 3, 3, 0),
    xwwy = _gs(0, 3, 3, 1),
    xwwz = _gs(0, 3, 3, 2),
    xwww = _gs(0, 3, 3, 3),
    //-------------------------
    yxxx = _gs(1, 0, 0, 0),
    yxxy = _gs(1, 0, 0, 1),
    yxxz = _gs(1, 0, 0, 2),
    yxxw = _gs(1, 0, 0, 3),
    yxyx = _gs(1, 0, 1, 0),
    yxyy = _gs(1, 0, 1, 1),
    yxyz = _gs(1, 0, 1, 2),
    yxyw = _gs(1, 0, 1, 3),
    yxzx = _gs(1, 0, 2, 0),
    yxzy = _gs(1, 0, 2, 1),
    yxzz = _gs(1, 0, 2, 2),
    yxzw = _gs(1, 0, 2, 3),
    yxwx = _gs(1, 0, 3, 0),
    yxwy = _gs(1, 0, 3, 1),
    yxwz = _gs(1, 0, 3, 2),
    yxww = _gs(1, 0, 3, 3),

    yyxx = _gs(1, 1, 0, 0),
    yyxy = _gs(1, 1, 0, 1),
    yyxz = _gs(1, 1, 0, 2),
    yyxw = _gs(1, 1, 0, 3),
    yyyx = _gs(1, 1, 1, 0),
    yyyy = _gs(1, 1, 1, 1),
    yyyz = _gs(1, 1, 1, 2),
    yyyw = _gs(1, 1, 1, 3),
    yyzx = _gs(1, 1, 2, 0),
    yyzy = _gs(1, 1, 2, 1),
    yyzz = _gs(1, 1, 2, 2),
    yyzw = _gs(1, 1, 2, 3),
    yywx = _gs(1, 1, 3, 0),
    yywy = _gs(1, 1, 3, 1),
    yywz = _gs(1, 1, 3, 2),
    yyww = _gs(1, 1, 3, 3),

    yzxx = _gs(1, 2, 0, 0),
    yzxy = _gs(1, 2, 0, 1),
    yzxz = _gs(1, 2, 0, 2),
    yzxw = _gs(1, 2, 0, 3),
    yzyx = _gs(1, 2, 1, 0),
    yzyy = _gs(1, 2, 1, 1),
    yzyz = _gs(1, 2, 1, 2),
    yzyw = _gs(1, 2, 1, 3),
    yzzx = _gs(1, 2, 2, 0),
    yzzy = _gs(1, 2, 2, 1),
    yzzz = _gs(1, 2, 2, 2),
    yzzw = _gs(1, 2, 2, 3),
    yzwx = _gs(1, 2, 3, 0),
    yzwy = _gs(1, 2, 3, 1),
    yzwz = _gs(1, 2, 3, 2),
    yzww = _gs(1, 2, 3, 3),

    ywxx = _gs(1, 3, 0, 0),
    ywxy = _gs(1, 3, 0, 1),
    ywxz = _gs(1, 3, 0, 2),
    ywxw = _gs(1, 3, 0, 3),
    ywyx = _gs(1, 3, 1, 0),
    ywyy = _gs(1, 3, 1, 1),
    ywyz = _gs(1, 3, 1, 2),
    ywyw = _gs(1, 3, 1, 3),
    ywzx = _gs(1, 3, 2, 0),
    ywzy = _gs(1, 3, 2, 1),
    ywzz = _gs(1, 3, 2, 2),
    ywzw = _gs(1, 3, 2, 3),
    ywwx = _gs(1, 3, 3, 0),
    ywwy = _gs(1, 3, 3, 1),
    ywwz = _gs(1, 3, 3, 2),
    ywww = _gs(1, 3, 3, 3),
    //-------------------------
    zxxx = _gs(2, 0, 0, 0),
    zxxy = _gs(2, 0, 0, 1),
    zxxz = _gs(2, 0, 0, 2),
    zxxw = _gs(2, 0, 0, 3),
    zxyx = _gs(2, 0, 1, 0),
    zxyy = _gs(2, 0, 1, 1),
    zxyz = _gs(2, 0, 1, 2),
    zxyw = _gs(2, 0, 1, 3),
    zxzx = _gs(2, 0, 2, 0),
    zxzy = _gs(2, 0, 2, 1),
    zxzz = _gs(2, 0, 2, 2),
    zxzw = _gs(2, 0, 2, 3),
    zxwx = _gs(2, 0, 3, 0),
    zxwy = _gs(2, 0, 3, 1),
    zxwz = _gs(2, 0, 3, 2),
    zxww = _gs(2, 0, 3, 3),

    zyxx = _gs(2, 1, 0, 0),
    zyxy = _gs(2, 1, 0, 1),
    zyxz = _gs(2, 1, 0, 2),
    zyxw = _gs(2, 1, 0, 3),
    zyyx = _gs(2, 1, 1, 0),
    zyyy = _gs(2, 1, 1, 1),
    zyyz = _gs(2, 1, 1, 2),
    zyyw = _gs(2, 1, 1, 3),
    zyzx = _gs(2, 1, 2, 0),
    zyzy = _gs(2, 1, 2, 1),
    zyzz = _gs(2, 1, 2, 2),
    zyzw = _gs(2, 1, 2, 3),
    zywx = _gs(2, 1, 3, 0),
    zywy = _gs(2, 1, 3, 1),
    zywz = _gs(2, 1, 3, 2),
    zyww = _gs(2, 1, 3, 3),

    zzxx = _gs(2, 2, 0, 0),
    zzxy = _gs(2, 2, 0, 1),
    zzxz = _gs(2, 2, 0, 2),
    zzxw = _gs(2, 2, 0, 3),
    zzyx = _gs(2, 2, 1, 0),
    zzyy = _gs(2, 2, 1, 1),
    zzyz = _gs(2, 2, 1, 2),
    zzyw = _gs(2, 2, 1, 3),
    zzzx = _gs(2, 2, 2, 0),
    zzzy = _gs(2, 2, 2, 1),
    zzzz = _gs(2, 2, 2, 2),
    zzzw = _gs(2, 2, 2, 3),
    zzwx = _gs(2, 2, 3, 0),
    zzwy = _gs(2, 2, 3, 1),
    zzwz = _gs(2, 2, 3, 2),
    zzww = _gs(2, 2, 3, 3),

    zwxx = _gs(2, 3, 0, 0),
    zwxy = _gs(2, 3, 0, 1),
    zwxz = _gs(2, 3, 0, 2),
    zwxw = _gs(2, 3, 0, 3),
    zwyx = _gs(2, 3, 1, 0),
    zwyy = _gs(2, 3, 1, 1),
    zwyz = _gs(2, 3, 1, 2),
    zwyw = _gs(2, 3, 1, 3),
    zwzx = _gs(2, 3, 2, 0),
    zwzy = _gs(2, 3, 2, 1),
    zwzz = _gs(2, 3, 2, 2),
    zwzw = _gs(2, 3, 2, 3),
    zwwx = _gs(2, 3, 3, 0),
    zwwy = _gs(2, 3, 3, 1),
    zwwz = _gs(2, 3, 3, 2),
    zwww = _gs(2, 3, 3, 3),
    //-------------------------
    wxxx = _gs(3, 0, 0, 0),
    wxxy = _gs(3, 0, 0, 1),
    wxxz = _gs(3, 0, 0, 2),
    wxxw = _gs(3, 0, 0, 3),
    wxyx = _gs(3, 0, 1, 0),
    wxyy = _gs(3, 0, 1, 1),
    wxyz = _gs(3, 0, 1, 2),
    wxyw = _gs(3, 0, 1, 3),
    wxzx = _gs(3, 0, 2, 0),
    wxzy = _gs(3, 0, 2, 1),
    wxzz = _gs(3, 0, 2, 2),
    wxzw = _gs(3, 0, 2, 3),
    wxwx = _gs(3, 0, 3, 0),
    wxwy = _gs(3, 0, 3, 1),
    wxwz = _gs(3, 0, 3, 2),
    wxww = _gs(3, 0, 3, 3),

    wyxx = _gs(3, 1, 0, 0),
    wyxy = _gs(3, 1, 0, 1),
    wyxz = _gs(3, 1, 0, 2),
    wyxw = _gs(3, 1, 0, 3),
    wyyx = _gs(3, 1, 1, 0),
    wyyy = _gs(3, 1, 1, 1),
    wyyz = _gs(3, 1, 1, 2),
    wyyw = _gs(3, 1, 1, 3),
    wyzx = _gs(3, 1, 2, 0),
    wyzy = _gs(3, 1, 2, 1),
    wyzz = _gs(3, 1, 2, 2),
    wyzw = _gs(3, 1, 2, 3),
    wywx = _gs(3, 1, 3, 0),
    wywy = _gs(3, 1, 3, 1),
    wywz = _gs(3, 1, 3, 2),
    wyww = _gs(3, 1, 3, 3),

    wzxx = _gs(3, 2, 0, 0),
    wzxy = _gs(3, 2, 0, 1),
    wzxz = _gs(3, 2, 0, 2),
    wzxw = _gs(3, 2, 0, 3),
    wzyx = _gs(3, 2, 1, 0),
    wzyy = _gs(3, 2, 1, 1),
    wzyz = _gs(3, 2, 1, 2),
    wzyw = _gs(3, 2, 1, 3),
    wzzx = _gs(3, 2, 2, 0),
    wzzy = _gs(3, 2, 2, 1),
    wzzz = _gs(3, 2, 2, 2),
    wzzw = _gs(3, 2, 2, 3),
    wzwx = _gs(3, 2, 3, 0),
    wzwy = _gs(3, 2, 3, 1),
    wzwz = _gs(3, 2, 3, 2),
    wzww = _gs(3, 2, 3, 3),

    wwxx = _gs(3, 3, 0, 0),
    wwxy = _gs(3, 3, 0, 1),
    wwxz = _gs(3, 3, 0, 2),
    wwxw = _gs(3, 3, 0, 3),
    wwyx = _gs(3, 3, 1, 0),
    wwyy = _gs(3, 3, 1, 1),
    wwyz = _gs(3, 3, 1, 2),
    wwyw = _gs(3, 3, 1, 3),
    wwzx = _gs(3, 3, 2, 0),
    wwzy = _gs(3, 3, 2, 1),
    wwzz = _gs(3, 3, 2, 2),
    wwzw = _gs(3, 3, 2, 3),
    wwwx = _gs(3, 3, 3, 0),
    wwwy = _gs(3, 3, 3, 1),
    wwwz = _gs(3, 3, 3, 2),
    wwww = _gs(3, 3, 3, 3),
};

#undef _gs