public static int Compare(CollisionResult a, CollisionResult b)
{
return a.Distance.CompareTo(b.Distance);
}
public static int Compare(CollisionResult a, CollisionResult b)
{
return(a.Distance.CompareTo(b.Distance));
}
/// <summary>
/// Determine all collisions that will happen as the given actor moves.
/// </summary>
/// <param name="actor">The actor that is moving.</param>
/// <param name="movement">The actor's movement vector this update.</param>
/// <remarks>The results are stored in the cached list.</remarks>
public void Collide(Actor actor, Vector2 movement)
{
collisionResults.Clear();
if (actor == null)
{
throw new ArgumentNullException("actor");
}
if (actor.Dead || (actor.Collidable == false))
{
return;
}
// determine the movement direction and scalar
float movementLength = movement.Length();
if (movementLength <= 0f)
{
return;
}
// check each actor
foreach (Actor checkActor in actors)
{
if ((actor == checkActor) || checkActor.Dead || !checkActor.Collidable)
{
continue;
}
// calculate the target vector
Vector2 checkVector = checkActor.Position - actor.Position;
float distanceBetween = checkVector.Length() -
(checkActor.Radius + actor.Radius);
// check if they could possibly touch no matter the direction
if (movementLength < distanceBetween)
{
continue;
}
// determine how much of the movement is bringing the two together
float movementTowards = Vector2.Dot(movement, checkVector);
// check to see if the movement is away from each other
if (movementTowards < 0f)
{
continue;
}
if (movementTowards < distanceBetween)
{
continue;
}
CollisionResult result = new CollisionResult();
result.Distance = distanceBetween;
result.Normal = Vector2.Normalize(checkVector);
result.Actor = checkActor;
collisionResults.Add(result);
}
}
/// <summary>
/// Determine all collisions that will happen as the given actor moves.
/// </summary>
/// <param name="actor">The actor that is moving.</param>
/// <param name="movement">The actor's movement vector this update.</param>
/// <remarks>The results are stored in the cached list.</remarks>
public void Collide(Actor actor, Vector2 movement)
{
collisionResults.Clear();
if (actor == null)
{
throw new ArgumentNullException("actor");
}
if (actor.Dead || (actor.Collidable == false))
{
return;
}
// determine the movement direction and scalar
float movementLength = movement.Length();
if (movementLength <= 0f)
{
return;
}
// check each actor
foreach (Actor checkActor in actors)
{
if ((actor == checkActor) || checkActor.Dead || !checkActor.Collidable)
{
continue;
}
// calculate the target vector
Vector2 checkVector = checkActor.Position - actor.Position;
float distanceBetween = checkVector.Length() -
(checkActor.Radius + actor.Radius);
// check if they could possibly touch no matter the direction
if (movementLength < distanceBetween)
{
continue;
}
// determine how much of the movement is bringing the two together
float movementTowards = Vector2.Dot(movement, checkVector);
// check to see if the movement is away from each other
if (movementTowards < 0f)
{
continue;
}
if (movementTowards < distanceBetween)
{
continue;
}
CollisionResult result = new CollisionResult();
result.Distance = distanceBetween;
result.Normal = Vector2.Normalize(checkVector);
result.Actor = checkActor;
collisionResults.Add(result);
}
}
