/// from http://pastie.org/3152377
/// <summary>
/// Get the depth of the vertical intersection between the two boxes.
/// </summary>
/// <param name="boxA">A box.</param>
/// <param name="boxB">Another box.</param>
/// <returns>The depth of the vertical intersection, negative if up,
/// positive if down.</returns>
public static float GetVerticalIntersectionDepth(BBox boxA, BBox boxB)
{
// Calculate half sizes.
float halfHeightA = boxA.Height / 2.0f;
float halfHeightB = boxB.Height / 2.0f;
// Calculate centers.
float centerA = boxA.Top + halfHeightA;
float centerB = boxB.Top + halfHeightB;
// Calculate current and minimum-non-intersecting distances between centers.
float distanceY = centerA - centerB;
float minDistanceY = halfHeightA + halfHeightB;
// If we are not intersecting at all, return (0, 0).
if (Math.Abs(distanceY) >= minDistanceY)
return 0f;
// Calculate and return intersection depths.
return distanceY > 0 ? minDistanceY - distanceY : -minDistanceY - distanceY;
}
/// from http://pastie.org/3152377
/// <summary>
/// Get the depth of the horizontal interesection between two boxes.
/// </summary>
/// <param name="boxA">A box.</param>
/// <param name="boxB">Another box.</param>
/// <returns>The depth of the horizontal intersection, negative if left,
/// positive if right.</returns>
public static float GetHorizontalIntersectionDepth(BBox boxA, BBox boxB)
{
// Calculate half sizes.
float halfWidthA = boxA.Width / 2.0f;
float halfWidthB = boxB.Width / 2.0f;
// Calculate centers.
float centerA = boxA.Left + halfWidthA;
float centerB = boxB.Left + halfWidthB;
// Calculate current and minimum-non-intersecting distances between centers.
float distanceX = centerA - centerB;
float minDistanceX = halfWidthA + halfWidthB;
// If we are not intersecting at all, return (0, 0).
if (Math.Abs(distanceX) >= minDistanceX)
return 0f;
// Calculate and return intersection depths.
return distanceX > 0 ? minDistanceX - distanceX : -minDistanceX - distanceX;
}
/// <summary>
/// Resolves the collision in a region between this object
/// and another.
/// </summary>
/// <param name="other">The other object being collided with.</param>
/// <param name="region">The region of collision.</param>
public virtual void Collide(GameObject other, BBox region) {
}
/// <summary>
/// Whether or not this object should collide with another object.
/// </summary>
/// <param name="other">The other object to check for a collision
/// against.</param>
/// <param name="region">The region of collision. An empty bounding box
/// if the objects do not collide.</param>
/// <returns>True if the objects should collide, false otherwise.</returns>
internal bool ShouldCollide(GameObject other, out BBox region)
{
region = BBox.Intersect(other.BBox);
return !region.IsEmpty();
}
public BBox Intersect(BBox other)
{
return new BBox(Rectangle.Intersect(box, other.box));
}
/**
* Handle collision events.
**/
public override void Collide(GameObject other, BBox region)
{
if (!HasCollided && (!other.Equals(owner)))
{
OnCollision();
/**base.Collide(other, region);**/
}
}
