public override void Update()
{
if (Owner.FixedDeltaTime == 0)
{
return;
}
accumulator += Owner.DeltaTime;
int timesExecuted = 0;
while (accumulator >= Owner.FixedDeltaTime)
{
timesExecuted++;
accumulator -= Owner.FixedDeltaTime;
foreach (Physical ph in WatchedComponents.Where(c => c is Physical))
{
if (!ph.Owner.Active)
{
continue;
}
ph.PreviousPosition = ph.Position;
ph.Velocity += Gravity * ph.GravityMultiplier * Owner.FixedDeltaTime;
ph.Position += ph.Velocity * Owner.FixedDeltaTime;
ph.Position = ph.Position.GetRounded();
ph.Velocity = ph.Velocity.GetRounded();
ph.PreviousVelocity = ph.Velocity;
}
WatchedComponents = WatchedComponents.OrderBy(a => GetCrossTickLeft(a)).ToList();
//Handle collision
foreach (Component c0 in WatchedComponents)
{
if (c0 is Physical)
{
continue;
}
if (!c0.Owner.Active)
{
continue;
}
double x = GetCrossTickLeft(c0);
while (sweeper.Count > 0 && !IntersectsX(sweeper[0], x))
{
sweeper.RemoveAt(0);
}
foreach (Component c1 in sweeper)
{
if (c0 is RigidBody && c1 is RigidBody)
{
continue;
}
SoftBody objA = c0 is SoftBody ? (SoftBody)c0 : (SoftBody)c1;
Component objB = objA == c0 ? c1 : c0;
if (objA.PassThroughLevel && objB is RigidBody)
{
continue;
}
Physical physA = objA.Owner.Components.Get <Physical>();
Physical physB = objB.Owner.Components.Get <Physical>();
if (physA == null || physB == null)
{
continue;
}
if (objB is RigidBody rb && !rb.UnionBounds.Offset(physB.Position).IntersectsWith(objA.Bounds.Offset(physA.Position)))
{
continue;
}
IEnumerable <CollisionBox> solidBoxes =
objB is SoftBody ?
new CollisionBox[] { (objB as SoftBody).Bounds.Offset(physB.Position) } :
(objB as RigidBody).Bounds.Select(b => b.Offset(physB.Position));
foreach (CollisionBox otherBounds in solidBoxes)
{
CollisionBox intersection = objA.Bounds.Offset(physA.Position).Intersect(otherBounds);
if (intersection != null)
{
collisions.Add(new SingleCollision(objA, objB, otherBounds, intersection));
}
}
}
foreach (SingleCollision collision in collisions.OrderByDescending(c => c.intersection.Area))
{
SoftBody objA = collision.objA;
Component objB = collision.objB;
Physical physA = objA.Owner.Components.Get <Physical>();
Physical physB = objB.Owner.Components.Get <Physical>();
CollisionBox otherBounds = collision.box;
CollisionBox intersection = objA.Bounds.Offset(physA.Position).Intersect(otherBounds);
if (intersection == null)
{
continue;
}
if (objB is RigidBody) //Hard collision
{
Vector2D totalVelocity = physA.PreviousVelocity - physB.Velocity;
List <FreeVector2D> sides = intersection.GetSides().Where(s => BelongsToBox(s, otherBounds)).Where(s => GeneralUtil.SubtractAngles(s.Normal.Angle, totalVelocity.Angle) > Math.PI / 2).ToList();
if (sides.Count == 0) //It's "stuck" inside a tile or that tile doesn't have one of the sides enabled
{
continue;
}
FreeVector2D normalSide = sides[0];
Vector2D normal = sides[0].Normal;
if (normal == Vector2D.Empty)
{
continue;
}
if (sides.Count > 1)
{
if (IsAheadOfNormal(objA.Bounds.Offset(physA.PreviousPosition), sides[0]))
{
if (IsAheadOfNormal(objA.Bounds.Offset(physA.PreviousPosition), sides[1]))
{
normalSide = sides[0].Normal.X == 0 ? sides[0] : sides[1];
}
else
{
normalSide = sides[0];
}
}
else
{
normalSide = sides[1];
}
normal = normalSide.Normal;
}
CollisionFaceProperties faceProperties = intersection.GetFaceProperties(normal);
if (objA.Movable)
{
if (normal.X == 0)
{
double displacement = Math.Abs(normalSide.A.Y - (normal.Y > 0 ? objA.Bounds.Offset(physA.Position).Bottom : objA.Bounds.Offset(physA.Position).Top));
if (faceProperties.Snap || Math.Round(displacement, 8) <= Math.Round(Math.Abs(physA.Position.Y - physA.PreviousPosition.Y) + Math.Abs(physB.Position.Y - physB.PreviousPosition.Y), 8))
{
physA.Position += new Vector2D(0, displacement) * normal.Y;
physA.Velocity = new Vector2D(physA.Velocity.X * (1 - faceProperties.Friction), 0) + physB.Velocity * faceProperties.Friction;
}
else
{
continue;
}
}
else
{
double displacement = Math.Abs(normalSide.A.X - (normal.X > 0 ? objA.Bounds.Offset(physA.Position).Left : objA.Bounds.Offset(physA.Position).Right));
if (faceProperties.Snap || Math.Round(displacement, 8) <= Math.Round(Math.Abs(physA.Position.X - physA.PreviousPosition.X) + Math.Abs(physB.Position.X - physB.PreviousPosition.X), 8))
{
physA.Position += new Vector2D(displacement, 0) * normal.X;
physA.Velocity = new Vector2D(0, physA.Velocity.Y * (1 - faceProperties.Friction)) + physB.Velocity * faceProperties.Friction;
}
else
{
continue;
}
}
}
Owner.Events.InvokeEvent(new RigidCollisionEvent(objA, objB.Owner, normal));
Owner.Events.InvokeEvent(new RigidCollisionEvent(objB, objA.Owner, normal));
}
else //Soft Collision
{
Owner.Events.InvokeEvent(new SoftCollisionEvent(objA, objB.Owner));
Owner.Events.InvokeEvent(new SoftCollisionEvent(objB, objA.Owner));
Vector2D center0 = objA.Bounds.Offset(physA.Position).Center;
Vector2D center1 = otherBounds.Center;
double distance = (center0 - center1).Magnitude;
if (distance <= 1e-4)
{
continue;
}
double force = 2 * Owner.FixedDeltaTime * intersection.Area * (objA.Mass * (objB as SoftBody).Mass);
Vector2D forceVec = (center1 - center0).Normalize() * force;
forceVec.Y = 0;
if (objA.Movable && objA.Mass != 0)
{
physA.Velocity -= forceVec / (objA.Mass);
}
if ((objB as SoftBody).Movable && (objB as SoftBody).Mass != 0)
{
physB.Velocity -= -forceVec / (objB as SoftBody).Mass;
}
}
}
collisions.Clear();
sweeper.Add(c0);
}
}
sweeper.Clear();
collisions.Clear();
}