/// <summary>
/// Trace the path quickly through to determine its length
/// </summary>
/// <param name="p_points">
/// A <see cref="Point"/> array of 4 points specifying Bezier curve
/// </param>
/// <returns>
/// A <see cref="System.Int32"/> as the length of the given curve
/// </returns>
static public int CalculateCurveLength(Point [] p_points)
{
if (p_points.Length != 4)
{
throw new Exception("p_points array passed to CalculateCurveLength must have exactly 4 items, this one has " + p_points.Length);
}
PointF pA = p_points[0];
double rtn = 0.0d;
// determine what ratio gives up about 1 pixel of distance
double accuracyRatio = BezierSprite.CalculateRatioSizeToPixelAccuracy(p_points, 1);
// set an incrementer
double currentRatio = accuracyRatio;
// set a limit for when we reach the end of the path - allow some overshoot
double topLimit = 1.0 + accuracyRatio;
// traverse path one fraction bit at a time calculating distances between points
while (currentRatio < topLimit)
{
PointF pB = CalculatePoint(p_points, currentRatio);
rtn += Math.Sqrt(Math.Pow(pA.X - pB.X, 2) + Math.Pow(pA.Y - pB.Y, 2));
pA = pB;
currentRatio += accuracyRatio;
}
return((int)Math.Round(rtn));
}
