/// <summary>
/// Returns true if a contact should not be disabled due to portal clipping.
/// </summary>
private bool IsContactValid(Contact contact)
{
FixtureData[] fixtureData = new FixtureData[2];
fixtureData[0] = FixtureExt.GetData(contact.FixtureA);
fixtureData[1] = FixtureExt.GetData(contact.FixtureB);
BodyData[] bodyData = new BodyData[2];
bodyData[0] = BodyExt.GetData(contact.FixtureA.Body);
bodyData[1] = BodyExt.GetData(contact.FixtureB.Body);
Xna.Vector2 normal;
FixedArray2<Xna.Vector2> vList;
contact.GetWorldManifold(out normal, out vList);
if (bodyData[0].IsChild || bodyData[1].IsChild)
{
if (bodyData[0].IsChild && bodyData[1].IsChild)
{
//return true;
}
int childIndex = bodyData[0].IsChild ? 0 : 1;
int otherIndex = bodyData[0].IsChild ? 1 : 0;
BodyData bodyDataChild = bodyData[childIndex];
BodyData bodyDataOther = bodyData[otherIndex];
FixtureData fixtureDataChild = fixtureData[childIndex];
FixtureData fixtureDataOther = fixtureData[otherIndex];
}
//Contact is invalid if it is between two fixtures where one fixture is colliding with a portal on the other fixture.
if (fixtureData[0].IsPortalParentless() && fixtureData[1].IsPortalParentless())
{
for (int i = 0; i < fixtureData.Length; i++)
{
int iNext = (i + 1) % fixtureData.Length;
var intersection = fixtureData[iNext].GetPortalChildren().Intersect(fixtureData[i].PortalCollisions);
if (intersection.Count() > 0)
{
//Debug.Fail("Fixtures with portal collisions should be filtered.");
return false;
}
}
}
//Contact is invalid if it is too close to a portal.
foreach (IPortal p in Scene.GetPortalList())
{
if (!Portal.IsValid(p))
{
continue;
}
FixturePortal portal = p as FixturePortal;
if (portal != null)
{
//Don't consider this portal if its fixtures are part of the contact.
if (fixtureData[0].PartOfPortal(portal) || fixtureData[1].PartOfPortal(portal))
{
continue;
}
LineF line = new LineF(Portal.GetWorldVerts(portal));
double[] vDist = new double[] {
MathExt.PointLineDistance(vList[0], line, true),
MathExt.PointLineDistance(vList[1], line, true)
};
//Only consider contacts that are between the fixture this portal is parented too and some other fixture.
if (contact.FixtureA == FixtureExt.GetFixtureAttached(portal) || contact.FixtureB == FixtureExt.GetFixtureAttached(portal))
{
if (contact.Manifold.PointCount == 1)
{
if (vDist[0] < FixturePortal.CollisionMargin)
{
return false;
}
}
else if (vDist[0] < FixturePortal.CollisionMargin && vDist[1] < FixturePortal.CollisionMargin)
{
return false;
}
}
}
}
//Contact is invalid if it is on the opposite side of a colliding portal.
for (int i = 0; i < fixtureData.Length; i++)
{
int iNext = (i + 1) % fixtureData.Length;
foreach (IPortal portal in fixtureData[i].PortalCollisions)
{
LineF line = new LineF(Portal.GetWorldVerts(portal));
FixturePortal cast = portal as FixturePortal;
if (cast != null)
{
if (fixtureData[i].PartOfPortal(cast) || fixtureData[iNext].PartOfPortal(cast))
{
continue;
}
}
//Contact is invalid if it is on the opposite side of the portal from its body origin.
//Xna.Vector2 pos = BodyExt.GetData(fixtureData[i].Fixture.Body).PreviousPosition;
Vector2 pos = BodyExt.GetLocalOrigin(fixtureData[i].Fixture.Body);
bool oppositeSides0 = line.GetSideOf(vList[0]) != line.GetSideOf(pos);
Debug.Assert(contact.Manifold.PointCount > 0);
if (contact.Manifold.PointCount == 1)
{
if (oppositeSides0)
{
return false;
}
}
else
//else if (line.GetSideOf((vList[0] + vList[1])/2) != line.GetSideOf(pos))
{
bool oppositeSides1 = line.GetSideOf(vList[1]) != line.GetSideOf(pos);
/*if (oppositeSides0 && oppositeSides1)
{
return false;
}
if (oppositeSides0)
{
contact.Manifold.Points[0] = contact.Manifold.Points[1];
}
contact.Manifold.PointCount = 1;
return true;*/
if (!oppositeSides0 && !oppositeSides1)
{
continue;
}
if (!fixtureData[iNext].PortalCollisions.Contains(portal) || !(oppositeSides0 || oppositeSides1))
{
return false;
}
}
}
}
return true;
}
private void PreSolveListener(Contact contact, ref Manifold oldManifold)
{
if (contact.IsTouching)
{
Debug.Assert(contact.Manifold.PointCount > 0);
/* Sometimes a body will tunnel through a portal fixture.
* The circumstances aren't well understood but checking if the contact normal
* is facing from fixtureB to fixtureA (it should always face from A to B
* according to the Box2D documentation) and then reversing the normal if it is
* helps prevent tunneling from occuring.*/
if (!FixtureExt.GetData(contact.FixtureA).IsPortalParentless() || !FixtureExt.GetData(contact.FixtureB).IsPortalParentless())
{
Xna.Vector2 normal;
FixedArray2<Xna.Vector2> vList;
contact.GetWorldManifold(out normal, out vList);
Vector2 center0 = FixtureExt.GetCenterWorld(contact.FixtureA);
Vector2 center1 = FixtureExt.GetCenterWorld(contact.FixtureB);
if (Math.Abs(MathExt.AngleDiff(center1 - center0, (Vector2)normal)) > Math.PI / 2)
{
contact.Manifold.LocalNormal *= -1;
}
}
if (!IsContactValid(contact))
{
contact.Enabled = false;
//return;
}
else
{
Actor actor0 = BodyExt.GetData(contact.FixtureA.Body).Actor;
Actor actor1 = BodyExt.GetData(contact.FixtureB.Body).Actor;
actor0.CallOnCollision(actor1, true);
actor1.CallOnCollision(actor0, false);
}
#region Debug
if (DebugMode)
{
FixtureData[] userData = new FixtureData[2];
userData[0] = FixtureExt.GetData(contact.FixtureA);
userData[1] = FixtureExt.GetData(contact.FixtureB);
Xna.Vector2 normal;
FixedArray2<Xna.Vector2> vList;
contact.GetWorldManifold(out normal, out vList);
if (contact.Manifold.PointCount == 2)
{
Model line = ModelFactory.CreateLines(
new LineF[] {
new LineF(vList[0], vList[1])
});
if (contact.Enabled)
{
line.SetColor(new Vector3(1, 1, 0.2f));
}
else
{
line.SetColor(new Vector3(0.5f, 0.5f, 0));
}
line.Transform.Position += new Vector3(0, 0, 5);
DebugEntity.AddModel(line);
}
for (int i = 0; i < 2; i++)
{
float scale = 0.8f;
Vector3 pos = new Vector3(vList[i].X, vList[i].Y, 5);
//Ignore contact points that are exactly on the origin. These are almost certainly null values.
if (pos.X == 0 && pos.Y == 0)
{
continue;
}
Vector2 arrowNormal = (Vector2)normal * 0.2f * scale;
if (i == 0)
{
arrowNormal *= -1;
}
Model arrow = ModelFactory.CreateArrow(pos, arrowNormal, 0.02f * scale, 0.05f * scale, 0.03f * scale);
DebugEntity.AddModel(arrow);
Model model = ModelFactory.CreateCube();
model.Transform.Scale = new Vector3(0.08f, 0.08f, 0.08f) * scale;
DebugEntity.AddModel(model);
if (contact.Enabled)
{
model.SetColor(new Vector3(1, 1, 0.2f));
arrow.SetColor(new Vector3(1, 1, 0.2f));
}
else
{
model.SetColor(new Vector3(0.5f, 0.5f, 0));
arrow.SetColor(new Vector3(0.5f, 0.5f, 0));
}
if (userData[0].IsPortalParentless() && userData[1].IsPortalParentless())
{
arrow.SetColor(new Vector3(0.7f, 0.5f, 0.2f));
}
model.Transform.Position = pos;
if (!userData[i].IsPortalParentless())
{
IList<Vector2> vertices = Vector2Ext.ToOtk(((PolygonShape)userData[i].Fixture.Shape).Vertices);
Model fixtureModel = ModelFactory.CreatePolygon(vertices);
fixtureModel.SetColor(new Vector3(0, 1, 1));
fixtureModel.Transform = userData[i].Actor.GetTransform().Get3D();
fixtureModel.Transform.Position += new Vector3(0, 0, 5);
fixtureModel.Transform.Scale = Vector3.One;
DebugEntity.AddModel(fixtureModel);
}
}
}
#endregion
}
}
public static FixtureData SetData(Fixture fixture)
{
FixtureData userData = new FixtureData(fixture);
fixture.UserData = userData;
return userData;
}
