FastSin

static double[]             table = null;
static double               step;
static double               invStep;
static int                  size  = 0;

static
{
    size = 10000;
    table = new double[size];
    step = 2d * Math.PI / size;
    invStep = 1.0f / step;
    for (int i = 0; i < size; ++i)
    {
        table[i] = Math.sin(step * i);
    }
}

/** Find a linear interpolation from the table
 * 
 * @param ang
 *            angle in radians
 * @return sin of angle a
 */
private final static double pi2   = PI * 2;

final public static double sin(double ang)
{
    double t = ang % pi2;
    int indexA = (int) (t / step);
    int indexB = indexA + 1;
    if (indexB >= size) return table[indexA];
    double a = table[indexA];
    return a + (table[indexB] - a) * (t - (indexA * step)) * invStep;
}