public static RSpatialRelation Relation(BoundingBox a, Bounding.Cylinder b)
{
// NOTE: Not tested thoroughly!
/*
* This all is based on finding the intersections between the axises of the box
* */
float m, n;
float boxMinZ = a.Minimum.Z; float boxMaxZ = a.Maximum.Z;
float cylMinZ = b.Position.Z; float cylMaxZ = cylMinZ + b.Height;
RSpatialRelation verticalRelation = Relation1DLines(boxMinZ, boxMaxZ, cylMinZ, cylMaxZ);
if (verticalRelation == RSpatialRelation.Outside)
{
return(RSpatialRelation.Outside);
}
// from this point on we know that the cylinder at least intersects the box on the vertical axis
//X Axis, first find intersections
CylP x1 = CylP.NotIntersecting;
if (Math.CircleXAxisIntersection(b.Position, b.Radius, a.Minimum.Y, out m, out n))
{
if (m > a.Maximum.X || n < a.Minimum.X)
{
x1 = CylP.Outside;
}
else if (m < a.Minimum.X && n > a.Maximum.X)
{
x1 = CylP.AInsideB;
}
else
{
return(RSpatialRelation.Intersect);
}
}
CylP x2 = CylP.NotIntersecting;
if (Math.CircleXAxisIntersection(b.Position, b.Radius, a.Maximum.Y, out m, out n))
{
if (m > a.Maximum.X || n < a.Minimum.X)
{
x2 = CylP.Outside;
}
else if (m < a.Minimum.X && n > a.Maximum.X)
{
x2 = CylP.AInsideB;
}
else
{
return(RSpatialRelation.Intersect);
}
}
//Y Axis, first find intersections
CylP y1 = CylP.NotIntersecting;
if (Math.CircleYAxisIntersection(b.Position, b.Radius, a.Minimum.X, out m, out n))
{
if (m > a.Maximum.Y || n < a.Minimum.Y)
{
y1 = CylP.Outside;
}
else if (m < a.Minimum.Y && n > a.Maximum.Y)
{
y1 = CylP.AInsideB;
}
else
{
return(RSpatialRelation.Intersect);
}
}
CylP y2 = CylP.NotIntersecting;
if (Math.CircleYAxisIntersection(b.Position, b.Radius, a.Maximum.X, out m, out n))
{
if (m > a.Maximum.Y || n < a.Minimum.Y)
{
y2 = CylP.Outside;
}
else if (m < a.Minimum.Y && n > a.Maximum.Y)
{
y2 = CylP.AInsideB;
}
else
{
return(RSpatialRelation.Intersect);
}
}
if (x1 == CylP.AInsideB && x2 == CylP.AInsideB && y1 == CylP.AInsideB && y2 == CylP.AInsideB)
{
if (verticalRelation == RSpatialRelation.AInsideB)
{
return(RSpatialRelation.AInsideB);
}
return(RSpatialRelation.Intersect);
}
//var horizontalRelation = RectCircleRelation(new RectangleF(new PointF(a.Minimum.X, a.Minimum.Y), new SizeF(a.Maximum.X - a.Minimum.X, a.Maximum.Y - a.Minimum.Y)), b);
//if (horizontalRelation == RSpatialRelation.Outside)
// return RSpatialRelation.Outside;
//else if (horizontalRelation == verticalRelation)
// return horizontalRelation;
//else
// return RSpatialRelation.Intersect;
if (x1 == CylP.NotIntersecting && x2 == CylP.NotIntersecting &&
y1 == CylP.NotIntersecting && y2 == CylP.NotIntersecting &&
Intersection.Intersect(a, Math.ToVector2(b.Position)))
{
if (verticalRelation == RSpatialRelation.BInsideA)
{
return(RSpatialRelation.BInsideA);
}
return(RSpatialRelation.Intersect);
}
else
{
return(RSpatialRelation.Outside);
}
#if false
//We start by checking if the circle is so large it covers the whole rectangle
bool intersects = false, ainsideb = true;
if (p.CullPoint(position.X, position.Y) == ECull.Intersect)
{
intersects = true;
}
else
{
ainsideb = false;
}
if (p.CullPoint(position.X + size.X, position.Y) == ECull.Intersect)
{
intersects = true;
}
else
{
ainsideb = false;
}
if (p.CullPoint(position.X, position.Y + size.Y) == ECull.Intersect)
{
intersects = true;
}
else
{
ainsideb = false;
}
if (p.CullPoint(position.X + size.X, position.Y + size.Y) == ECull.Intersect)
{
intersects = true;
}
else
{
ainsideb = false;
}
if (ainsideb)
{
return(RSpatialRelation.AInsideB);
}
if (intersects)
{
return(RSpatialRelation.Intersect);
}
//The find the point on the circle which is closest to the center of the rectangle
Vector3 k = center - p.Position;
if (k.LengthSquared() == 0)
{
k.X = 1;
}
Vector3 d = Vector3.Normalize(k) * p.Radius;
Vector3 a = p.Position + d;
//And check if it is outside the rectangle
if (CullPoint(a.X, a.Y) == ECull.Outside)
{
return(RSpatialRelation.Outside);
}
//The we take the point furthest away from the center
Vector3 b = p.Position - d;
if (CullPoint(b.X, b.Y) == ECull.Outside)
{
return(RSpatialRelation.Intersect);
}
return(RSpatialRelation.BInsideA);
#endif
}
