public bool FindIntersect(Point start, Point end, ref Point intersect, ref int index)
{
bool found = false;
double A1 = end.Y - start.Y;
double B1 = end.X - start.X;
double C1 = A1 * start.X + B1 * start.Y;
double path_dist = Get_Dist(start, end);
double i_dist = double.MaxValue;
//find which border get intersected by our line
//return the point of intersection and the index of the side intersected
for (int i = 0; i < PointList.Count; i++)
{
Point left = (Point)PointList[i];
Point right = (Point)PointList[Get_Right_Point(i)];
double A2 = right.Y - left.Y;
double B2 = right.X - left.X;
double C2 = A2 * left.X + B2 * left.Y;
double det = A1 * B2 - A2 * B1;
double c_x = (B2 * C1 - B1 * C2) / det;
double c_y = (A1 * C2 - A2 * C1) / det;
if ((c_x == left.X && c_y == left.Y) || (c_x == right.X && c_y == right.Y))
{
//ignore collision on the end points
}
else
{
//need to determine if this collision is between start <-> end
if (Util.MIN(left.X, right.X) <= c_x && c_x <= Util.MAX(left.X, right.X) &&
Util.MIN(left.Y, right.Y) <= c_y && c_y <= Util.MAX(left.Y, right.Y))
{
//if so... get the dist from start to the collision
// set intersect and i_dist
double n_dist = Math.Sqrt(Math.Pow(start.X - c_x, 2) + Math.Pow(start.Y - c_y, 2));
if (n_dist < i_dist)
{
i_dist = n_dist;
intersect.X = (float)c_x;
intersect.Y = (float)c_y;
index = i;//left point
found = true;
}
}
else
{
//not inside our line segment
}
}
}
return(found);
}
public bool IsPointInside(Point p)
{
if (PointList.Count < 3)
{
return(true);
}
int counter = 0;
//need to run rays and check for collision,
float xinters;
Point p1, p2;
int i;
try
{
p1 = (Point)PointList[0];
for (i = 1; i <= PointList.Count; i++)
{
p2 = (Point)PointList[i % PointList.Count];
if (p.Y > Util.MIN(p1.Y, p2.Y))
{
if (p.Y <= Util.MAX(p1.Y, p2.Y))
{
if (p.X <= Util.MAX(p1.X, p2.X))
{
if (p1.Y != p2.Y)
{
xinters = (p.Y - p1.Y) * (p2.X - p1.X) / (p2.Y - p1.Y) + p1.X;
if (p1.X == p2.X || p.X <= xinters)
{
counter++;
}
}
}
}
}
p1 = p2;
}
//next we do a modulus and return out result
if (counter % 2 == 0)
{
return(false);
}
return(true);
}
catch
{
Globals.l2net_home.Add_Error("border check failed... get those mexicans out of here!");
return(false);
}
}