/// <summary>
/// Handles the collisions.
/// </summary>
/// <param name="direction">The direction.</param>
/// <param name="source">The source.</param>
public static void HandleCollisions(Direction direction, IMovingCollidable source)
{
// Safety-check the singleton
if (_collisionManager == null)
{
return;
}
if (source.IsActive)
{
var sourcePreviousBoundingBox = source.PreviousBoundingBox;
// Loop through the possible targets
foreach (var target in _collisionManager._collisionTree.Retrieve(source))
{
// Initialize variables
var sourceBoundingBox = source.BoundingBox;
var targetBoundingBox = target.BoundingBox;
// Determine if source and target currently overlap (e.g. a collision has occurred
if ((source != target) && sourceBoundingBox.Intersects(targetBoundingBox))
{
// Initialize the variables
var collisionOffset = Vector2.Zero;
var sourceDirection = Direction.None;
var targetDirection = Direction.None;
// Evaluate only in the directions specfied
if (direction.HasFlag(Direction.Top))
{
// Source Top
if (source.PreviousBoundingBox.Top >= targetBoundingBox.Bottom)
{
collisionOffset = new Vector2(collisionOffset.X, targetBoundingBox.Bottom - sourceBoundingBox.Top);
sourceDirection |= Direction.Top;
targetDirection |= Direction.Bottom;
}
}
if (direction.HasFlag(Direction.Bottom))
{
// Source Bottom
if (source.PreviousBoundingBox.Bottom <= targetBoundingBox.Top)
{
collisionOffset = new Vector2(collisionOffset.X, targetBoundingBox.Top - sourceBoundingBox.Bottom);
sourceDirection |= Direction.Bottom;
targetDirection |= Direction.Top;
}
}
if (direction.HasFlag(Direction.Left))
{
// Source Left
if (source.PreviousBoundingBox.Left >= targetBoundingBox.Right)
{
collisionOffset = new Vector2(targetBoundingBox.Right - sourceBoundingBox.Left, collisionOffset.Y);
sourceDirection |= Direction.Left;
targetDirection |= Direction.Right;
}
}
if (direction.HasFlag(Direction.Right))
{
// Source Right
if (source.PreviousBoundingBox.Right <= targetBoundingBox.Left)
{
collisionOffset = new Vector2(targetBoundingBox.Left - sourceBoundingBox.Right, collisionOffset.Y);
sourceDirection |= Direction.Right;
targetDirection |= Direction.Left;
}
}
// Handle the collision if one occurred
if (sourceDirection != Direction.None)
{
// Tell the source and target about the collision
source.HandleCollisions(new CollisionInfo(source, target, sourceDirection, collisionOffset));
target.HandleCollisions(new CollisionInfo(target, source, targetDirection, -collisionOffset));
}
}
}
}
}
private static void TryCorrectPosition(Rectangle tryPosition, TFirst moveableObject, ICollidable collidable, IMovingCollidable movingCollidable, bool correctX, bool correctY, bool correctPastOriginal = false)
{
float newX = tryPosition.Center.X;
float newY = tryPosition.Center.Y;
float deltaX = 0, deltaY = 0;
if (correctPastOriginal)
{
newX = newX.Approach(moveableObject.Motion.FrameStartPosition.Center.X, 1);
newY = newY.Approach(moveableObject.Motion.FrameStartPosition.Center.Y, 1);
deltaX = (newX - moveableObject.Motion.FrameStartPosition.Center.X).Unit();
deltaY = (newY - moveableObject.Motion.FrameStartPosition.Center.Y).Unit();
if (deltaX == 0 && deltaY == 0)
{
if (movingCollidable == null)
{
deltaY = -1;
}
else
{
deltaY = (newY - movingCollidable.Position.Center.Y).Unit();
}
}
}
while (collidable.DetectCollision(tryPosition, true))
{
float newX2 = newX, newY2 = newY;
if (correctPastOriginal)
{
newX2 = newX + deltaX;
newY2 = newY + deltaY;
}
else
{
if (correctX)
{
newX2 = newX.Approach(moveableObject.Motion.FrameStartPosition.Center.X, 1);
}
if (correctY)
{
newY2 = newY.Approach(moveableObject.Motion.FrameStartPosition.Center.Y, 1);
}
}
if (newX2 == newX && newY2 == newY)
{
newX = newX2;
newY = newY2;
break;
}
else
{
newX = newX2;
newY = newY2;
}
tryPosition.Center = new Vector2(newX, newY);
}
}
