public static bool boxAndBox(
BoxRigid one,
BoxRigid two,
ref CollisionData data
)
{
if (!IntersectionTestsboxAndBox(one, two))
{
return(false);
}
// Find the vector between the two centres
Vector3 toCentre = two.PositionCenterEngine - one.PositionCenterEngine;
// We start assuming there is no contact
float pen = float.MaxValue;
int best = 0xffffff;
// Now we check each axes, returning if it gives us
// a separating axis, and keeping track of the axis with
// the smallest penetration otherwise.
if (!tryAxis(one, two, (one).XAxis, toCentre, 0, ref pen, ref best))
{
return(false);
}
if (!tryAxis(one, two, (one).YAxis, toCentre, 1, ref pen, ref best))
{
return(false);
}
if (!tryAxis(one, two, (two).XAxis, toCentre, 2, ref pen, ref best))
{
return(false);
}
if (!tryAxis(one, two, (two).YAxis, toCentre, 3, ref pen, ref best))
{
return(false);
}
// Store the best axis-major, in case we run into almost
// parallel edge collisions later
int bestSingleAxis = best;
// Make sure we've got a result.
if (best != 0xffffff)
{
// We now know there's a collision, and we know which
// of the axes gave the smallest penetration. We now
// can deal with it in different ways depending on
// the case.
if (best < 2)
{
// We've got a vertex of box two on a face of box one.
fillPointFaceBoxBox(one, two, toCentre, ref data, best, pen);
one.SetCanSleep(true);
two.SetCanSleep(true);
data.addContacts(1);
}
else if (best < 4)
{
fillPointFaceBoxBox(two, one, toCentre * -1.0f, ref data, best - 2, pen);
one.SetCanSleep(true);
two.SetCanSleep(true);
data.addContacts(1);
}
return(true);
}
return(false);
}
public static bool boxAndHalfSpace(
BoxRigid box,
CollisionPlane plane,
ref CollisionData data
)
{
// Make sure we have contacts
if (data.contactsLeft <= 0)
{
return(false);
}
// Check for intersection
if (!IntersectionTestboxAndHalfSpace(box, plane))
{
return(false);
}
bool b = false;
int contactsUsed = 0;
for (int i = 0; i < 4; i++)
{
Vector3 vertexPos = ((BoxRigid)box).vertices[i].Position;
// Calculate the distance from the plane
float vertexDistance = Vector3.Dot(vertexPos, plane.Direction);
// Compare this to the plane's distance
if (vertexDistance <= plane.Offset)
{
b = true;
// Create the contact data.
// The contact point is halfway between the vertex and the
// plane - we multiply the direction by half the separation
// distance and add the vertex location.
Contact c = new Contact();
c.ContactPoint = plane.Direction;
c.ContactPoint *= (0.5f * (plane.Offset - vertexDistance));
c.ContactPoint = vertexPos;
c.ContactNormal = plane.Direction;
c.Penetration = plane.Offset - vertexDistance;
c.Particle[0] = box;
c.Particle[1] = null;
c.Friction = data.friction;
c.Restitution = data.restitution;
c.Friction = StaticData.FrictionTable[(int)plane.Material][(int)box.GetMaterial()];
c.Restitution = StaticData.RestitutionTable[(int)plane.Material][(int)box.GetMaterial()];
c.ContactToWorld.M11 = plane.Direction.X;
c.ContactToWorld.M12 = -plane.Direction.Y;
c.ContactToWorld.M21 = plane.Direction.Y;
c.ContactToWorld.M22 = plane.Direction.X;
data.contacts.Add(c);
box.SetCanSleep(true);
data.index++;
data.contactsLeft--;
data.contactCount++;
contactsUsed++;
}
}
return(b);
}
