public static bool CircleOverConvexPolygon(Circle c, ConvexPolygon p)
{
if (p.ContainsPoint(c.Center))
{
return(true);
}
float r2 = c.Radius * c.Radius;
for (int i = 0, j = p.Vertices.Length - 1; i < p.Vertices.Length; j = i++)
{
if (XY.SqrDistance(c.Center, p.Vertices [i]) < r2)
{
return(true);
}
if (
XY.Dot(c.Center - p.Vertices [i], p.Vertices [j] - p.Vertices [i]) >= 0 &&
XY.Dot(c.Center - p.Vertices [j], p.Vertices [i] - p.Vertices [j]) >= 0 &&
DistancePointToLine(c.Center, p.Vertices [i], p.Vertices [j]) < c.Radius
)
{
return(true);
}
}
return(false);
}
public static bool CircleOverCircle(Circle c1, Circle c2)
{
float d2 = XY.SqrDistance(c1.Center, c2.Center);
float rr = c1.Radius + c2.Radius;
return(d2 <= rr * rr);
}
public static bool Overlap(Circle c1, Circle c2, Circle c3)
{
if (!CircleOverCircle(c1, c2))
{
return(false);
}
if (CircleInCircle(c1, c2))
{
return(CircleOverCircle(c1.Radius < c2.Radius ? c1 : c2, c3));
}
float r1 = c1.Radius, r2 = c2.Radius, r3 = c3.Radius;
XY o1 = c1.Center, o2 = c2.Center, o3 = c3.Center;
float rr1 = r1 * r1;
float dist = XY.Distance(o1, o2);
float a = 0.5f * ((rr1 - r2 * r2) / dist + dist);
float h = Mathf.Sqrt(rr1 - a * a);
var i = (o2 - o1) / dist;
var o = o1 + i * a;
i.Rotate90CCW();
var i1 = o + i * h;
var i2 = o - i * h;
if (XY.Cross(i1 - o1, o3 - o1) >= 0 && XY.Cross(o3 - o2, i1 - o2) >= 0)
{
return(XY.SqrDistance(o3, i1) <= r3 * r3);
}
if (XY.Cross(i2 - o2, o3 - o2) >= 0 && XY.Cross(o3 - o1, i2 - o1) >= 0)
{
return(XY.SqrDistance(o3, i2) <= r3 * r3);
}
return(CircleOverCircle(c1, c3) && CircleOverCircle(c2, c3));
}
public static bool CircleInCircle(Circle c1, Circle c2)
{
// какой круг в каком, это надо сравнить радиусы, здесь мы это не считаем
float d2 = XY.SqrDistance(c1.Center, c2.Center);
float rr = c1.Radius - c2.Radius;
return(d2 <= rr * rr);
}
public static bool CircleOverBox(Circle c, Box b)
{
var p = c.Center.Clamped(b);
return(XY.SqrDistance(p, c.Center) <= c.Radius * c.Radius);
}