BezierPathCalc.m

NSPoint PSYPointInBezierPath(NSPoint *points, NSInteger pointCount, CGFloat t,
                                    NSPoint *getPoints, NSInteger getPointCount)
{
    if(getPointCount > 0 && pointCount == getPointCount)
        for(int i = 0; i < getPointCount; i++)
            getPoints[i] = points[i];

    if(pointCount <= 1) return *points;
        
    NSPoint *newPoints = calloc(pointCount - 1, sizeof(NSPoint));
    for(int i = 0; i < pointCount - 1; i++)
    {
        newPoints[i].x = t * (points[i+1].x - points[i].x) + points[i].x;
        newPoints[i].y = t * (points[i+1].y - points[i].y) + points[i].y;
    }
    
    NSPoint ret = PSYPointInBezierPath(newPoints, pointCount - 1, t, getPoints, getPointCount);
    
    free(newPoints);
    
    return ret;
}