Interpolation/Spline/Vectors

B-Spline Interpolation between four vector points in a list of vectors that define a path.
Returns a vector

vector pSpline(list v, float t, integer Loop) {
    integer l = llGetListLength(v); t *= l-1;
    integer f = llFloor(t); t -= f;
    float t2 = t * t; float t3 = t2 * t;
    return (
      ( (-t3 + (3.*t2) - (3.*t) + 1.) * llList2Vector(v, pIndex(f-1,l,Loop)) )
    + ( ((3.*t3) - (6.*t2) + 4.) * llList2Vector(v, pIndex(f,l,Loop)) )
    + ( ((-3.*t3) + (3.*t2) + (3.*t) + 1.) * llList2Vector(v, pIndex(f+1,l,Loop)) )
    + ( t3 * llList2Vector(v, pIndex(f+2,l,Loop)) )
    ) / 6.0;
}
integer pIndex( integer Index, integer Length, integer Loop) {
    if(Loop) return Index % Length;
    if(Index < 0) return 0;
    if(Index > --Length) return Length;
    return Index;
}
// Released into public domain. By Nexii Malthus.