public void CalcBounds()
{
if (Points == null || Points.Length == 0)
{
Bounds = RectangleD.Empty;
}
else
{
double l = Points[0].X, r = l;
double t = Points[0].Y, b = t;
for (int i = 1; i < Points.Length; i++)
{
if (Points[i].X < l)
{
l = Points[i].X;
}
else if (Points[i].X > r)
{
r = Points[i].X;
}
if (Points[i].Y < t)
{
t = Points[i].Y;
}
else if (Points[i].Y > b)
{
b = Points[i].Y;
}
}
Bounds = RectangleD.FromLTRB(l, t, r, b);
}
}
public static RectangleD Intersect(RectangleD r1, RectangleD r2)
{
if (r1.Left > r2.Right || r1.Right < r2.Left || r1.Top > r2.Bottom || r1.Bottom < r2.Top)
{
return(RectangleD.Empty);
}
return(RectangleD.FromLTRB(Math.Max(r1.Left, r2.Left), Math.Max(r1.Top, r2.Top), Math.Min(r1.Right, r2.Right), Math.Min(r1.Bottom, r2.Bottom)));
}
public static bool PtInRgn(double x, double y, PointD[] region)
{
if (region.Length == 0)
{
return(false);
}
double l = region[0].X;
double r = l;
double t = region[0].Y;
double b = t;
for (int i = 1; i < region.Length; i++)
{
if (region[i].X > r)
{
r = region[i].X;
}
else
{
if (region[i].X < l)
{
l = region[i].X;
}
}
if (region[i].Y > b)
{
b = region[i].Y;
}
else
{
if (region[i].Y < t)
{
t = region[i].Y;
}
}
}
//RectangleD rd = new RectangleD(l, t, r - l, b - t);
RectangleD rd = RectangleD.FromLTRB(l, t, r, b);
if (!rd.Contains(x, y))
{
return(false);
}
int count = 0;
PointD start, end;
for (int i = 0; i < region.Length; i++)
{
start = region[i];
end = (i == region.Length - 1) ? region[0] : region[i + 1];
if (start.X == x && start.Y == y) //是顶点
{
return(true);
}
else
{
if (start.Y == y) //在X轴上
{
if (start.X > x) //在正半轴
{
if (end.Y == y) //边终点也在X轴上
{
if (end.X < x) //点在边上
{
return(true);
}
//否则该边可以当作一个顶点，忽略
}
else
{
if (end.Y < y)
{
count++;
}
//左算又不算
}
}
else//在负半轴上
{
if (end.Y == y && end.X > x) //点在边上
{
return(true);
}
}
}
else
{
if (end.Y == y) //边终点在X轴上
{
if (end.X > x && start.Y < y)
{
count++;
}
}
else
{
if (start.Y < y && end.Y < y)
{
continue;
}
if (start.Y > y && end.Y > y)
{
continue;
}
if (start.X == end.X)
{
if (start.X > x)
{
count++;
}
}
else
{
double x1 = (end.X * (start.Y - y) + start.X * (y - end.Y)) / (start.Y - end.Y);
if (x1 == x)
{
return(true);
}
else if (x1 > x)
{
count++;
}
}
}
}
}
}
return((count & 1) != 0);
}