/// <param name="depth">Number of iterations.</param>
/// <param name="clipModels">Adds the ClipModel instances to this list.</param>
private static List<ClipModel> _getClipModels(IRenderable entity, Model model, IList<IPortal> portalList, Vector2 centerPoint, IPortal portalEnter, Matrix4 modelMatrix, int depth, int count)
{
List<ClipModel> clipModels = new List<ClipModel>();
if (depth <= 0)
{
return clipModels;
}
List<IPortal> collisions = Portal.GetCollisions(
centerPoint,
Vector2Ext.Transform(model.GetWorldConvexHull(),
entity.GetWorldTransform().GetMatrix() * modelMatrix),
portalList,
PORTAL_CLIP_MARGIN);
List<LineF> clipLines = new List<LineF>();
foreach (IPortal portal in collisions)
{
Vector2[] pv = Portal.GetWorldVerts(portal);
LineF clipLine = new LineF(pv);
LineF portalLine = new LineF(pv);
Vector2 normal = portal.WorldTransform.GetRight();
if (portal.WorldTransform.MirrorX)
{
normal = -normal;
}
Vector2 portalNormal = portal.WorldTransform.Position + normal;
if (portalLine.GetSideOf(centerPoint) != portalLine.GetSideOf(portalNormal))
{
normal *= Portal.EnterMinDistance;
}
else
{
clipLine = clipLine.Reverse();
normal *= -Portal.EnterMinDistance;
}
clipLines.Add(clipLine);
if (portalEnter == null || portal != portalEnter.Linked)
{
Vector2 centerPointNext = Vector2Ext.Transform(portal.WorldTransform.Position + normal, Portal.GetLinkedMatrix(portal));
clipModels.AddRange(_getClipModels(entity, model, portalList, centerPointNext, portal, modelMatrix * Portal.GetLinkedMatrix(portal), depth - 1, count + 1));
}
}
clipModels.Add(new ClipModel(entity, model, clipLines.ToArray(), modelMatrix));
return clipModels;
}
public static Vector2 GetLocalOrigin(Body body)
{
BodyData data = GetData(body);
Vector2 center;
//If this isn't the root body then the center point will be just outside of the parent portal.
if (data.IsChild)
{
LineF portalLine = new LineF(Portal.GetWorldVerts(data.BodyParent.Portal.Linked));
Vector2 offset = portalLine.Delta.PerpendicularLeft.Normalized() * 0.01f;
center = portalLine.Center + offset;
if (portalLine.GetSideOf(center + offset) == portalLine.GetSideOf(body.Position))
{
center = portalLine.Center - offset;
}
}
else
{
center = (Vector2)body.Position;
}
return center;
}
/// <summary>
/// Determine a position that is sufficiently far away from all portals so that it isn't ambiguous which side of a
/// portal the position is at.
/// </summary>
/// <param name="portals"></param>
/// <param name="portalPrevious">The last portal that was exited.</param>
/// <param name="transform"></param>
/// <param name="velocity"></param>
private static Transform2 AddMargin(IEnumerable<IPortal> portals, IPortal portalPrevious, Transform2 transform, Transform2 velocity)
{
transform = transform.ShallowClone();
foreach (IPortal p in portals)
{
if (!Portal.IsValid(p))
{
continue;
}
LineF exitLine = new LineF(Portal.GetWorldVerts(p));
Vector2 position = transform.Position;
double distanceToPortal = MathExt.PointLineDistance(position, exitLine, true);
if (distanceToPortal < Portal.EnterMinDistance)
{
Vector2 exitNormal = p.WorldTransform.GetRight();
Side sideOf;
if (p == portalPrevious)
{
sideOf = exitLine.GetSideOf(position + velocity.Position);
}
else
{
sideOf = exitLine.GetSideOf(position - velocity.Position);
}
if (sideOf != exitLine.GetSideOf(exitNormal + p.WorldTransform.Position))
{
exitNormal = -exitNormal;
}
Vector2 pos = exitNormal * (Portal.EnterMinDistance - (float)distanceToPortal);
transform.Position += pos;
break;
}
}
return transform;
}
/// <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;
}
/// <summary>
/// Get all valid portals that collide with a polygon. Portals can occlude eachother.
/// </summary>
/// <param name="margin">Minimum distance inside of polygon for a portal collision to count.
/// Useful for avoiding round off errors.</param>
public static List<IPortal> GetCollisions(Vector2 center, IList<Vector2> polygon, IList<IPortal> portals, double margin = 0)
{
List<IPortal> collisions = new List<IPortal>();
foreach (IPortal p in portals.Where(item => IsValid(item)))
{
LineF portalLine = new LineF(GetWorldVerts(p));
if (MathExt.LineInPolygon(portalLine, polygon) &&
(margin == 0 ||
MathExt.PointPolygonDistance(portalLine[0], polygon) > margin ||
MathExt.PointPolygonDistance(portalLine[1], polygon) > margin))
{
collisions.Add(p);
}
}
var ordered = collisions.OrderBy(item => (item.WorldTransform.Position - center).Length).ToList();
for (int i = 0; i < ordered.Count; i++)
{
IPortal portal = ordered[i];
for (int j = ordered.Count - 1; j > i; j--)
{
LineF currentLine = new LineF(GetWorldVerts(ordered[i]));
LineF checkLine = new LineF(GetWorldVerts(ordered[j]));
Side checkSide = currentLine.GetSideOf(checkLine);
if (checkSide != currentLine.GetSideOf(center))
{
ordered.RemoveAt(j);
}
}
}
return ordered.ToList();
}
public void GetSideOfTest14()
{
float rot = 0;
for (int i = 0; i < 10; i++)
{
Vector2 v0 = new Vector2((float)Math.Cos(rot), (float)Math.Sin(rot));
Vector2 v1 = new Vector2((float)Math.Cos(rot + Math.PI), (float)Math.Sin(rot + Math.PI));
Vector2 v2 = new Vector2((float)Math.Cos(rot + Math.PI/2), (float)Math.Sin(rot + Math.PI/2));
LineF line = new LineF(v0, v1);
Assert.IsTrue(line.GetSideOf(v2) == Side.Right);
}
}
public void GetSideOfTest13()
{
LineF line = new LineF(new Vector2(5, 20), new Vector2(10, 25));
LineF lineCheck = new LineF(new Vector2(-25, 10), new Vector2(25, 10));
Assert.IsTrue(line.GetSideOf(lineCheck) == Side.Neither);
}
public void GetSideOfTest12()
{
LineF line = new LineF(new Vector2(-5, 20), new Vector2(20, 0));
Assert.IsFalse(line.GetSideOf(new Vector2(0, 0)) == Side.Left);
}
public void GetSideOfTest11()
{
LineF line = new LineF(new Vector2(-1, 1), new Vector2(0, 0));
Assert.IsFalse(line.GetSideOf(new Vector2(0, -100)) == Side.Left);
}
public void GetSideOfTest1()
{
LineF line = new LineF(new Vector2(0, 0), new Vector2(1, 0));
Assert.IsTrue(line.GetSideOf(new Vector2(0, 100)) == Side.Left);
}
private static bool _isPortalValid(IPortal previous, IPortal next, Vector2 viewPos)
{
//skip this portal if it isn't linked
if (!Portal.IsValid(next))
{
return false;
}
//or it's the exit portal
if (previous != null && next == previous.Linked)
{
return false;
}
//or if the portal is one sided and the view point is on the wrong side
Vector2[] pv2 = Portal.GetWorldVerts(next);
LineF portalLine = new LineF(pv2);
if (next.OneSided)
{
if (portalLine.GetSideOf(pv2[0] + next.WorldTransform.GetRight()) != portalLine.GetSideOf(viewPos))
{
return false;
}
}
//or if this portal isn't inside the fov of the exit portal
if (previous != null)
{
LineF portalEnterLine = new LineF(Portal.GetWorldVerts(previous.Linked));
if (!portalEnterLine.IsInsideFOV(viewPos, portalLine))
{
return false;
}
}
return true;
}
private static List<ClipPolygon> _getClipModels(IList<Vector2> polygon, IList<IPortal> portalList, Vector2 centerPoint, IPortal portalEnter, Matrix4 modelMatrix, int depth, int count)
{
List<ClipPolygon> clipModels = new List<ClipPolygon>();
if (depth <= 0)
{
return clipModels;
}
List<IPortal> collisions = new List<IPortal>();
foreach (IPortal portal in portalList)
{
if (!Portal.IsValid(portal))
{
continue;
}
LineF portalLine = new LineF(Portal.GetWorldVerts(portal));
List<Vector2> convexHull = new List<Vector2>(polygon);
convexHull.Add(centerPoint);
convexHull = (List<Vector2>)Vector2Ext.Transform(MathExt.GetConvexHull(convexHull, true), modelMatrix);
if (MathExt.LinePolygonDistance(portalLine, convexHull) < PORTAL_CLIP_MARGIN)
{
collisions.Add(portal);
}
}
collisions = collisions.OrderBy(item => (item.WorldTransform.Position - centerPoint).Length).ToList();
for (int i = 0; i < collisions.Count; i++)
{
IPortal portal = collisions[i];
for (int j = collisions.Count - 1; j > i; j--)
{
LineF currentLine = new LineF(Portal.GetWorldVerts(collisions[i]));
LineF checkLine = new LineF(Portal.GetWorldVerts(collisions[j]));
Side checkSide = currentLine.GetSideOf(checkLine);
if (checkSide != currentLine.GetSideOf(centerPoint))
{
collisions.RemoveAt(j);
}
}
}
List<LineF> clipLines = new List<LineF>();
foreach (IPortal portal in collisions)
{
Vector2[] pv = Portal.GetWorldVerts(portal);
LineF clipLine = new LineF(pv);
LineF portalLine = new LineF(pv);
Vector2 normal = portal.WorldTransform.GetRight();
if (portal.WorldTransform.MirrorX)
{
normal = -normal;
}
Vector2 portalNormal = portal.WorldTransform.Position + normal;
if (portalLine.GetSideOf(centerPoint) != portalLine.GetSideOf(portalNormal))
{
normal *= Portal.EnterMinDistance;
}
else
{
clipLine = clipLine.Reverse();
normal *= -Portal.EnterMinDistance;
}
clipLines.Add(clipLine);
if (portalEnter == null || portal != portalEnter.Linked)
{
Vector2 centerPointNext = Vector2Ext.Transform(portal.WorldTransform.Position + normal, Portal.GetLinkedMatrix(portal));
clipModels.AddRange(_getClipModels(polygon, portalList, centerPointNext, portal, modelMatrix * Portal.GetLinkedMatrix(portal), depth - 1, count + 1));
}
}
clipModels.Add(new ClipPolygon(polygon, clipLines.ToArray(), modelMatrix));
return clipModels;
}
