public void HandlePhysicalCollision(CollisionSystem.Pair actor, CollisionComponent target, GameTime gameTime, bool swept) //TODO Implement Swept CC sometime
{
if (swept)
{
float entryTime = SweptAABB(actor, target, gameTime, out var normalX, out var normalY);
if (entryTime <= 0 || entryTime >= 1)
{
return;
}
MoveToEntry(actor, entryTime, gameTime);
HandleCollisionResponseBehavior(actor, normalX, normalY);
ApplyRemainingSpeed(actor, 1 - entryTime, gameTime);
}
else
{
if ((actor.Collision.IsPhasing || target.IsPhasing) && (!target.IsWall))
{
return;
}
if (actor.Collision.CollisionRectangle.Intersects(target.CollisionRectangle))
{
Vector2 penetrationVector = ClosestPointOnBoundsToPoint(CalculateMinkowskiDifference(actor.Collision.CollisionRectangle, target.CollisionRectangle), Vector2.Zero);
actor.Collision.CollisionRectangle -= penetrationVector;
Point normals = PenetrationToNormals(penetrationVector);
HandleCollisionResponseBehavior(actor, normals.X, normals.Y);
}
}
AlignMovementWithCollision(actor);
}
private static void BlockActor(CollisionSystem.Pair actor, int normalX, int normalY)
{
if (normalX != 0)
{
actor.Movement.Speed.ChangeX(0);
}
if (normalY != 0)
{
actor.Movement.Speed.ChangeY(0);
}
}
private void HandleCollisionResponseBehavior(CollisionSystem.Pair actor, int normalX, int normalY)
{
if (actor.Collision.Behavior == CollisionBehavior.Block)
{
BlockActor(actor, normalX, normalY);
}
else if (actor.Collision.Behavior == CollisionBehavior.Bounce)
{
BounceActor(actor, normalX, normalY);
}
}
private static float SweptAABB(CollisionSystem.Pair actor, CollisionComponent target, GameTime gameTime, out int normalX, out int normalY) //TODO THIS ALGORITHM IS NOT FUNCTIONAL, TOO LAZY TO FIX IT NOW
{
float xEntryDistance, yEntryDistance;
float xExitDistance, yExitDistance;
#region calculate distances
if (actor.Movement.Speed.Cartesian.X > 0.0f)
{
xEntryDistance = target.CollisionRectangle.X - (actor.Collision.CollisionRectangle.X + actor.Collision.CollisionRectangle.Width);
xExitDistance = (target.CollisionRectangle.X + target.CollisionRectangle.Width) - actor.Collision.CollisionRectangle.X;
}
else
{
xEntryDistance = (target.CollisionRectangle.X + target.CollisionRectangle.Width) - actor.Collision.CollisionRectangle.X;
xExitDistance = target.CollisionRectangle.X - (actor.Collision.CollisionRectangle.X + actor.Collision.CollisionRectangle.Width);
}
if (actor.Movement.Speed.Cartesian.Y > 0.0f)
{
yEntryDistance = target.CollisionRectangle.Y - (actor.Collision.CollisionRectangle.Y + actor.Collision.CollisionRectangle.Height);
yExitDistance = (target.CollisionRectangle.Y + target.CollisionRectangle.Height) - actor.Collision.CollisionRectangle.Y;
}
else
{
yEntryDistance = (target.CollisionRectangle.Y + target.CollisionRectangle.Height) - actor.Collision.CollisionRectangle.Y;
yExitDistance = target.CollisionRectangle.Y - (actor.Collision.CollisionRectangle.Y + actor.Collision.CollisionRectangle.Height);
}
#endregion
float xEntryTime, yEntryTime;
float xExitTime, yExitTime;
#region calculate entry and exit times
if (actor.Movement.Speed.Cartesian.X == 0.0f)
{
xEntryTime = float.NegativeInfinity;
xExitTime = float.PositiveInfinity;
}
else
{
xEntryTime = xEntryDistance / (actor.Movement.Speed.Cartesian.X * (float)gameTime.ElapsedGameTime.TotalSeconds);
xExitTime = xExitDistance / (actor.Movement.Speed.Cartesian.Y * (float)gameTime.ElapsedGameTime.TotalSeconds);
}
if (actor.Movement.Speed.Cartesian.Y == 0.0f)
{
yEntryTime = float.NegativeInfinity;
yExitTime = float.PositiveInfinity;
}
else
{
yEntryTime = yEntryDistance / (actor.Movement.Speed.Cartesian.Y * (float)gameTime.ElapsedGameTime.TotalSeconds);
yExitTime = yExitDistance / (actor.Movement.Speed.Cartesian.Y * (float)gameTime.ElapsedGameTime.TotalSeconds);
}
#endregion
if (xEntryTime > 1.0f)
{
xEntryTime = -float.MaxValue;
}
if (yEntryTime > 1.0f)
{
yEntryTime = -float.MaxValue;
}
float entryTime = Math.Max(xEntryTime, yEntryTime);
float exitTime = Math.Min(xExitTime, yExitTime);
#region no collision happened
if ((entryTime > exitTime) || (xEntryTime < 0.0f && yEntryTime < 0.0f))
{
normalX = 0;
normalY = 0;
return(1.0f);
}
#endregion
#region set normals
if (xEntryTime > yEntryTime)
{
normalX = -1;
normalY = 1;
}
else
{
normalX = 1;
normalY = -1;
}
#endregion
return(entryTime);
}
private static void BounceActor(CollisionSystem.Pair actor, int normalX, int normalY)
{
actor.Movement.Speed.ChangeX(actor.Movement.Speed.Cartesian.X * normalX);
actor.Movement.Speed.ChangeY(actor.Movement.Speed.Cartesian.Y * normalY);
}
private static void AlignMovementWithCollision(CollisionSystem.Pair pair)
{
pair.Movement.Position.X = pair.Collision.CollisionRectangle.Center.X;
pair.Movement.Position.Y = pair.Collision.CollisionRectangle.Center.Y;
}
private static void ApplyRemainingSpeed(CollisionSystem.Pair actor, float remainingTime, GameTime gameTime)
{
actor.Collision.CollisionRectangle.X += (int)(actor.Movement.Speed.Cartesian.X * (remainingTime * (float)gameTime.ElapsedGameTime.TotalSeconds));
actor.Collision.CollisionRectangle.Y += (int)(actor.Movement.Speed.Cartesian.Y * (remainingTime * (float)gameTime.ElapsedGameTime.TotalSeconds));
}
private static void MoveToEntry(CollisionSystem.Pair actor, float entryTime, GameTime gameTime)
{
actor.Collision.CollisionRectangle.X += (int)(actor.Movement.Speed.Cartesian.X * (entryTime * (float)gameTime.ElapsedGameTime.TotalSeconds));
actor.Collision.CollisionRectangle.Y += (int)(actor.Movement.Speed.Cartesian.Y * (entryTime * (float)gameTime.ElapsedGameTime.TotalSeconds));
}
