//private static Vector2 ExitVector(Box collision, Box collisionWith)
//{
// Box intersection = Box.Intersect(collision, collisionWith);
// Vector2 intersectionVector = new Vector2(intersection.Width, intersection.Height);
// Vector2 directionVector = collision.Center - collisionWith.Center;
//
// if (directionVector == Vector2.Zero)
// {
// directionVector.X = -1;
// }
//
// Vector2 exitVector = intersectionVector * (directionVector / directionVector.Length());
//
// if ((exitVector.Y != 0) && (Math.Abs(exitVector.X) > Math.Abs(exitVector.Y)))
// {
// exitVector.X = 0;
// }
// else if ((exitVector.X != 0) && (Math.Abs(exitVector.Y) > Math.Abs(exitVector.X)))
// {
// exitVector.Y = 0;
// }
//
// return exitVector;
//}
public static void MovementCollision(KineticBox box, SpatialGrid spatialGrid)
{
//S'il y a vraiment collision
if (Intersect(box, spatialGrid.GetProbableSolidCollisions(box)))
{
Vector2 exitVector = box.OldLocation - box.Location;
KineticBox copy = ResolveMovementCollision(box, exitVector, spatialGrid);
Vector2 finalMovement = box.Location - copy.Location;
IEnumerable <Box> solids = spatialGrid.GetProbableSolidCollisions(copy);
if (((finalMovement.X < 0) && (LeftCollision(copy, solids))) ||
((finalMovement.X > 0) && ((RightCollision(copy, solids)))))
{
finalMovement.X = 0;
}
if (((finalMovement.Y < 0) && (TopCollision(copy, solids))) ||
((finalMovement.Y > 0) && (BottomCollision(copy, solids))))
{
finalMovement.Y = 0;
}
if (finalMovement != Vector2.Zero)
{
copy.Offset(finalMovement);
MovementCollision(copy, spatialGrid);
}
else
{
box.Speed = Vector2.Zero;
}
box.Location = copy.Location;
}
}
public PhysicsEngine(Game game, int width, int height)
: base(game)
{
boxes = new SortedList <int, Box>(new DuplicateKeyComparer <int>());
SpatialGrid = new SpatialGrid(Game, (int)Math.Ceiling((double)width / SpatialGrid.TILE_SIZE), (int)Math.Ceiling((double)height / SpatialGrid.TILE_SIZE));
DrawOrder = int.MaxValue;
}
public static void SetCollisionNotification(Box sender, SpatialGrid spatialGrid)
{
Box copy = new Box(sender);
copy.Inflate(1, 1);
foreach (Box aabb in spatialGrid.GetProbableCollisions(sender))
{
if (aabb.Intersects(copy))
{
sender.CollisionNotification(aabb);
}
}
copy.Inflate(-1, -1);
}
//C'est sacré
public static void StopSpeed(KineticBox box, SpatialGrid spatialGrid)
{
//Restore l'ancienne vitesse en vérifiant quels côtés ont fait la collision
IEnumerable <Box> solids = spatialGrid.GetProbableSolidCollisions(box);
if (((box.Speed.X <= 0) && (LeftCollision(box, solids))) ||
((box.Speed.X >= 0) && ((RightCollision(box, solids)))))
{
box.Speed.X = 0;
}
if (((box.Speed.Y <= 0) && (TopCollision(box, solids))) ||
((box.Speed.Y >= 0) && (BottomCollision(box, solids))))
{
box.Speed.Y = 0;
}
}
public static void ExpulseCollision(Box sender, SpatialGrid spatialGrid)
{
if (sender.Solid)
{
foreach (Box aabb in spatialGrid.GetProbableCollisions(sender))
{
if (aabb is KineticBox)
{
KineticBox box = aabb as KineticBox;
if ((box.InteractWithSolid) && (box.Intersects(sender)))
{
ClassicCollision(box, spatialGrid);
}
}
}
}
}
//Use with caution
public static void ClassicCollision(KineticBox sender, SpatialGrid spatialGrid)
{
if (sender.InteractWithSolid)
{
Vector2 exitVector = Vector2.Zero;
int total = 1;
foreach (Box collision in spatialGrid.GetProbableSolidCollisions(sender))
{
if (collision.Intersects(sender))
{
exitVector += sender.ExitVector(collision);
total++;
}
}
if (exitVector != Vector2.Zero)
{
exitVector /= total;
sender.Offset(exitVector);
}
}
}
private static KineticBox ResolveMovementCollision(KineticBox box, Vector2 exitVector, SpatialGrid spatialGrid)
{
KineticBox copy = new KineticBox(box);
//Tant que la collision n'est pas résolue
while (copy.Location != copy.OldLocation) //Pourrait être optimisé contre une perte de précision?
{
if (Intersect(copy, spatialGrid.GetProbableSolidCollisions(copy)))
{
//Défait le mouvement qui créer la collion
copy.Offset(exitVector);
}
else
{
//Avance plus lentement vers la collion
exitVector /= 2;
copy.Offset(-exitVector);
}
}
return(copy);
}
