static float PLdistance(Point3D c, Point3D a, Point3D b)
{
Point3D ab = b - a;
Point3D ac = c - a;
float f = Point3D.dotsProduct(ab, ac);
if (f + FloatCmp.EPS < 0)
{
return(Point3D.distance(c, a));
}
float d = Point3D.dotsProduct(ab, ab);
if (f > d)
{
return(Point3D.distance(c, b));
}
f = f / d;
Point3D D = a + f * ab; // c在ab线段上的投影点
return(Point3D.distance(c, D));
}
public static bool CircleIntersect(Circle c1, Circle c2)
{
/*float distance=(float)Math.Sqrt((c1.c.coord[0]-c2.c.coord[0])*(c1.c.coord[0]-c2.c.coord[0])
+(c1.c.coord[1]-c2.c.coord[1])*(c1.c.coord[1]-c2.c.coord[1])
+(c1.c.coord[2]-c2.c.coord[2])*(c1.c.coord[2]-c2.c.coord[2]));*/
if (Point3D.distance(c1.c, c2.c) <= c1.r + c2.r)
{
return(true);
}
else
{
return(false);
}
}