/// <summary>
/// Determines whether this <see cref="Segment2" /> intersects with the specified <see cref="BoundingRectangle" />.
/// </summary>
/// <param name="boundingRectangle">The bounding box.</param>
/// <param name="intersectionPoint">
/// When this method returns, contains the <see cref="Point2" /> of intersection, if an
/// intersection was found; otherwise, the <see cref="Point2.NaN" />. This parameter is passed uninitialized.
/// </param>
/// <returns>
/// <c>true</c> if this <see cref="Segment2" /> intersects with <paramref name="boundingRectangle" />; otherwise,
/// <c>false</c>.
/// </returns>
public bool Intersects(BoundingRectangle boundingRectangle, out Point2 intersectionPoint)
{
// Real-Time Collision Detection, Christer Ericson, 2005. Chapter 5.3; Basic Primitive Tests - Intersecting Lines, Rays, and (Directed Segments). pg 179-181
var minimumPoint = boundingRectangle.Center - boundingRectangle.HalfExtents;
var maximumPoint = boundingRectangle.Center + boundingRectangle.HalfExtents;
var minimumDistance = float.MinValue;
var maximumDistance = float.MaxValue;
var direction = End - Start;
if (
!PrimitivesHelper.IntersectsSlab(Start.X, direction.X, minimumPoint.X, maximumPoint.X, ref minimumDistance,
ref maximumDistance))
{
intersectionPoint = Point2.NaN;
return(false);
}
if (
!PrimitivesHelper.IntersectsSlab(Start.Y, direction.Y, minimumPoint.Y, maximumPoint.Y, ref minimumDistance,
ref maximumDistance))
{
intersectionPoint = Point2.NaN;
return(false);
}
// Segment intersects the 2 slabs.
if (minimumDistance <= 0)
{
intersectionPoint = Start;
}
else
{
intersectionPoint = minimumDistance * direction;
intersectionPoint.X += Start.X;
intersectionPoint.Y += Start.Y;
}
return(true);
}
/// <summary>
/// Determines whether this <see cref="Segment2" /> intersects with the specified <see cref="BoundingRectangle" />.
/// </summary>
/// <param name="rectangle">The bounding box.</param>
/// <param name="intersectionPoint">
/// When this method returns, contains the <see cref="PointF" /> of intersection, if an
/// intersection was found; otherwise, the <see cref="PointF.NaN" />. This parameter is passed uninitialized.
/// </param>
/// <returns>
/// <c>true</c> if this <see cref="Segment2" /> intersects with <paramref name="rectangle" />; otherwise,
/// <c>false</c>.
/// </returns>
public bool Intersects(RectangleF rectangle, out PointF intersectionPoint)
{
// Real-Time Collision Detection, Christer Ericson, 2005. Chapter 5.3; Basic Primitive Tests - Intersecting Lines, Rays, and (Directed Segments). pg 179-181
PointF minimumPoint = rectangle.TopLeft;
PointF maximumPoint = rectangle.BottomRight;
float minimumDistance = float.MinValue;
float maximumDistance = float.MaxValue;
var direction = End - Start;
if (!PrimitivesHelper.IntersectsSlab(
Start.X, direction.X, minimumPoint.X, maximumPoint.X, ref minimumDistance, ref maximumDistance))
{
intersectionPoint = PointF.NaN;
return(false);
}
if (!PrimitivesHelper.IntersectsSlab(
Start.Y, direction.Y, minimumPoint.Y, maximumPoint.Y, ref minimumDistance, ref maximumDistance))
{
intersectionPoint = PointF.NaN;
return(false);
}
// Segment intersects the 2 slabs.
if (minimumDistance <= 0)
{
intersectionPoint = Start;
}
else
{
intersectionPoint = minimumDistance * direction;
intersectionPoint.X += Start.X;
intersectionPoint.Y += Start.Y;
}
return(true);
}
/// <summary>
/// Determines whether this <see cref="Ray2D" /> intersects with a specified <see cref="BoundingRectangle" />.
/// </summary>
/// <param name="boundingRectangle">The bounding rectangle.</param>
/// <param name="rayNearDistance">
/// When this method returns, contains the distance along the ray to the first intersection
/// point with the <paramref name="boundingRectangle" />, if an intersection was found; otherwise,
/// <see cref="float.NaN" />.
/// This parameter is passed uninitialized.
/// </param>
/// <param name="rayFarDistance">
/// When this method returns, contains the distance along the ray to the second intersection
/// point with the <paramref name="boundingRectangle" />, if an intersection was found; otherwise,
/// <see cref="float.NaN" />.
/// This parameter is passed uninitialized.
/// </param>
/// <returns>
/// <c>true</c> if this <see cref="Ray2D" /> intersects with <paramref name="boundingRectangle" />; otherwise,
/// <c>false</c>.
/// </returns>
public bool Intersects(BoundingRectangle boundingRectangle, out float rayNearDistance, out float rayFarDistance)
{
// Real-Time Collision Detection, Christer Ericson, 2005. Chapter 5.3; Basic Primitive Tests - Intersecting Lines, Rays, and (Directed Segments). pg 179-181
var minimum = boundingRectangle.Center - boundingRectangle.HalfExtents;
var maximum = boundingRectangle.Center + boundingRectangle.HalfExtents;
// Set to the smallest possible value so the algorithm can find the first hit along the ray
var minimumDistanceAlongRay = float.MinValue;
// Set to the maximum possible value so the algorithm can find the last hit along the ray
var maximumDistanceAlongRay = float.MaxValue;
// For all relevant slabs which in this case is two.
// The first, horizontal, slab.
if (!PrimitivesHelper.IntersectsSlab(Position.X, Direction.X, minimum.X, maximum.X,
ref minimumDistanceAlongRay,
ref maximumDistanceAlongRay))
{
rayNearDistance = rayFarDistance = float.NaN;
return(false);
}
// The second, vertical, slab.
if (!PrimitivesHelper.IntersectsSlab(Position.Y, Direction.Y, minimum.Y, maximum.Y,
ref minimumDistanceAlongRay,
ref maximumDistanceAlongRay))
{
rayNearDistance = rayFarDistance = float.NaN;
return(false);
}
// Ray intersects the 2 slabs.
rayNearDistance = minimumDistanceAlongRay < 0 ? 0 : minimumDistanceAlongRay;
rayFarDistance = maximumDistanceAlongRay;
return(true);
}