/// <summary>
/// Internal helper function for computing intersections.
/// </summary>
private static bool IntersectVertical(ref RCIntRectangle lRect, ref RCIntRectangle rRect, out int intersectTop, out int intersectBottom)
{
if (lRect.Top <= rRect.Top && rRect.Top < lRect.Bottom && lRect.Bottom <= rRect.Bottom)
{
intersectTop = rRect.Top;
intersectBottom = lRect.Bottom;
return(true);
}
else if (rRect.Top <= lRect.Top && lRect.Top < lRect.Bottom && lRect.Bottom <= rRect.Bottom)
{
intersectTop = lRect.Top;
intersectBottom = lRect.Bottom;
return(true);
}
else if (rRect.Top <= lRect.Top && lRect.Top < rRect.Bottom && rRect.Bottom <= lRect.Bottom)
{
intersectTop = lRect.Top;
intersectBottom = rRect.Bottom;
return(true);
}
else
{
intersectTop = 0;
intersectBottom = 0;
return(false);
}
}
/// <summary>
/// Returns a third RCIntRectangle that represents the intersection of two other RCRectangles.
/// If there is no intersection, RCIntRectangle.Undefined is returned.
/// </summary>
/// <param name="lRect">An RCIntRectangle to intersect.</param>
/// <param name="rRect">An RCIntRectangle to intersect.</param>
/// <returns>
/// An RCIntRectangle that is the intersection of lRect and rRect or RCIntRectangle.Undefined if there is no intersection.
/// </returns>
public static RCIntRectangle Intersect(RCIntRectangle lRect, RCIntRectangle rRect)
{
if (!lRect.isDefined)
{
throw new ArgumentNullException("lRect");
}
if (!rRect.isDefined)
{
throw new ArgumentNullException("rRect");
}
int intersectLeft, intersectRight, intersectTop, intersectBottom;
/// Compute the horizontal coordinates of the intersection
if (!IntersectHorizontal(ref lRect, ref rRect, out intersectLeft, out intersectRight) &&
!IntersectHorizontal(ref rRect, ref lRect, out intersectLeft, out intersectRight))
{
return(RCIntRectangle.Undefined);
}
/// Compute the vertical coordinates of the intersection
if (!IntersectVertical(ref lRect, ref rRect, out intersectTop, out intersectBottom) &&
!IntersectVertical(ref rRect, ref lRect, out intersectTop, out intersectBottom))
{
return(RCIntRectangle.Undefined);
}
return(new RCIntRectangle(intersectLeft, intersectTop, intersectRight - intersectLeft, intersectBottom - intersectTop));
}
/// <summary>
/// Internal helper function for computing intersections.
/// </summary>
private static bool IntersectHorizontal(ref RCIntRectangle lRect, ref RCIntRectangle rRect, out int intersectLeft, out int intersectRight)
{
if ((lRect.Left <= rRect.Left && rRect.Left < lRect.Right && lRect.Right <= rRect.Right))
{
intersectLeft = rRect.Left;
intersectRight = lRect.Right;
return(true);
}
else if (rRect.Left <= lRect.Left && lRect.Left < lRect.Right && lRect.Right <= rRect.Right)
{
intersectLeft = lRect.Left;
intersectRight = lRect.Right;
return(true);
}
else if (rRect.Left <= lRect.Left && lRect.Left < rRect.Right && rRect.Right <= lRect.Right)
{
intersectLeft = lRect.Left;
intersectRight = rRect.Right;
return(true);
}
else
{
intersectLeft = 0;
intersectRight = 0;
return(false);
}
}
/// <summary>
/// Replaces this RCIntRectangle with the intersection of itself and the specified Rectangle.
/// </summary>
/// <param name="other">The other RCIntRectangle to intersect with.</param>
/// <remarks>
/// If this and other RCRectangles don't intersect each other, then this RCIntRectangle becomes RCIntRectangle.Undefined.
/// </remarks>
public void Intersect(RCIntRectangle other)
{
if (!this.isDefined)
{
throw new InvalidOperationException("Illegal use of undefined RCIntRectangle!");
}
if (!other.isDefined)
{
throw new ArgumentNullException("other");
}
this = RCIntRectangle.Intersect(this, other);
}
/// <summary>
/// Determines if this RCIntRectangle intersects with rect.
/// </summary>
/// <param name="rect">The RCIntRectangle to test.</param>
/// <returns>True if there is any intersection, false otherwise.</returns>
public bool IntersectsWith(RCIntRectangle rect)
{
if (!this.isDefined)
{
throw new InvalidOperationException("Illegal use of undefined RCIntRectangle!");
}
if (!rect.isDefined)
{
throw new ArgumentNullException("rect");
}
return((this.Left < rect.Right) && (this.Right > rect.Left) && (this.Top < rect.Bottom) && (this.Bottom > rect.Top));
}
/// <summary>
/// Initializes a new RCIntRectangle with the specified RCIntRectangle.
/// </summary>
/// <param name="other">The RCIntRectangle to initialize with.</param>
public RCIntRectangle(RCIntRectangle other)
{
if (!other.isDefined)
{
throw new ArgumentNullException("other");
}
this.isDefined = true;
this.x = other.x;
this.y = other.y;
this.width = other.width;
this.height = other.height;
}
/// <summary>
/// Determines if the rectangular region represented by rect is entirely contained within this RCIntRectangle.
/// </summary>
/// <param name="rect">The RCIntRectangle to test.</param>
/// <returns>True if the rectangular region represented by rect is entirely contained within this RCIntRectangle, false otherwise.</returns>
public bool Contains(RCIntRectangle rect)
{
if (!this.isDefined)
{
throw new InvalidOperationException("Illegal use of undefined RCIntRectangle!");
}
if (!rect.isDefined)
{
throw new ArgumentNullException("rect");
}
return(this.Contains(rect.x, rect.y) &&
this.Contains(rect.x + rect.width - 1, rect.y + rect.height - 1));
}
/// <summary>
/// Checks whether this RCIntRectangle has the same location and size as the specified RCIntRectangle.
/// </summary>
/// <param name="other">The RCIntRectangle to test.</param>
/// <returns>True if other RCIntRectangle has same location and size as this RCIntRectangle.</returns>
public bool Equals(RCIntRectangle other)
{
return((!this.isDefined && !other.isDefined) ||
(this.isDefined && other.isDefined && this.x == other.x && this.y == other.y &&
this.width == other.width && this.height == other.height));
}
