/// <summary>
/// Returns true if any part of this circle overlaps any part of line segment <paramref name='b'/>.
/// </summary>
/// <remarks>
/// If line <paramref name='b'/> lies within the circle, that counts as overlapping.
/// </remarks>
public bool Overlaps(WLineSegment b)
{
WPoint[] lineIntersectionPoints = GetIntersectionPoints(b.ToWLine());
if (lineIntersectionPoints == null)
{
return(false);
}
foreach (WPoint point in lineIntersectionPoints)
{
if (b.Overlaps(point))
{
return(true);
}
}
if (lineIntersectionPoints.Length == 2)
{
//if b lies entirely within the circle
WLineSegment intersectionLine = new WLineSegment(lineIntersectionPoints[0], lineIntersectionPoints[1]);
if (intersectionLine.Length > b.Length && intersectionLine.Overlaps(b))
{
return(true);
}
}
return(false);
}
/// <summary>
/// Returns true if the arc overlaps any part of the <paramref name='lineSegment'/>.
/// </summary>
public bool ArcOverlaps(WLineSegment lineSegment)
{
//find intersection points between full circle and line segment
WPoint[] fullCircleIntersections = Circle.GetIntersectionPoints(lineSegment);
if (fullCircleIntersections == null)
{
return(false);
}
//find degrees from circle center to intersection points
//are any of those degrees within the wedge degree range?
foreach (WPoint point in fullCircleIntersections)
{
double degrees = Circle.DegreesAtPoint(point);
if (Degrees.Overlaps(degrees))
{
return(true);
}
}
return(false);
}
//todo: is it worth making a Degree and a Radian struct? for being precise in what data is expected/returned?
/// <summary>Find the intersection points between the edge of this circle and the <paramref name='lineSegment'/>.</summary>
/// <returns>Null (no intercepts), or array of length 1, or array of length 2.</returns>
public WPoint[] GetIntersectionPoints(WLineSegment lineSegment)
{
WPoint[] lineIntersectionPoints = GetIntersectionPoints(lineSegment.ToWLine());
if (lineIntersectionPoints == null)
{
return(null);
}
List <WPoint> segmentIntersectionPoints = new List <WPoint>();
foreach (WPoint point in lineIntersectionPoints)
{
if (lineSegment.Overlaps(point))
{
segmentIntersectionPoints.Add(point);
}
}
if (segmentIntersectionPoints.Count == 0)
{
return(null);
}
return(segmentIntersectionPoints.ToArray());
}
/// <summary>Returns true if this line segments overlaps line segment <paramref name='b'/> at any point.</summary>
public bool Overlaps(WLineSegment b)
{
Intersection intersection = GetIntersection(b);
return(intersection != Intersection.NONE);
}
/// <summary>Returns intersection between a line segment and another line segment.</summary>
public override Intersection GetIntersection(WLineSegment that)
{
if (this.Parallel(that))
{
bool thisAOnThat = this.A.Overlaps(that);
bool thisBOnThat = this.B.Overlaps(that);
bool thatAOnThis = that.A.Overlaps(this);
bool thatBOnThis = that.B.Overlaps(this);
if (!thisAOnThat && !thisBOnThat && !thatAOnThis && !thatBOnThis)
{
return(Intersection.NONE);
}
if (thisAOnThat && thisBOnThat)
{
return(new Intersection(this));
}
if (thatAOnThis && thatBOnThis)
{
return(new Intersection(that));
}
WPoint overlapThis = null;
WPoint overlapThat = null;
if (thisAOnThat)
{
overlapThis = this.A;
}
else if (thisBOnThat)
{
overlapThis = this.B;
}
if (thatAOnThis)
{
overlapThat = that.A;
}
else if (thatBOnThis)
{
overlapThat = that.B;
}
if (overlapThis == null || overlapThat == null)
{
//should not reach this, but just in case
return(Intersection.NONE);
}
if (overlapThis == overlapThat)
{
return(new Intersection(overlapThis));
}
return(new Intersection(new WLineSegment(overlapThis, overlapThat)));
}
Intersection possibleIntersection = (this.ToWLine()).GetIntersection(that.ToWLine());
if (possibleIntersection.IsPoint && this.Overlaps(possibleIntersection.Point) && that.Overlaps(possibleIntersection.Point))
{
return(possibleIntersection);
}
return(Intersection.NONE);
}
/// <summary>Returns true if lines are coincidental to each other.</summary>
/// <remarks>Coincidental means that every point on this line is also on the other, and vice versa. In short, the lines are equal.</remarks>
public override bool Coincidental(WLineSegment b)
{
return(this.A == b.A && this.B == b.B);
}
/// <summary></summary>
public Intersection(WLineSegment lineSegment)
{
Type = IntersectionType.LineSegment;
this.lineSegment = lineSegment;
}
/// <summary>Returns false. An infinite line cannot be coincidental to a finite line.</summary>
public virtual bool Coincidental(WLineSegment b)
{
return(false);
}
/// <summary>Returns intersection between a line segment and a line.</summary>
public virtual Intersection GetIntersection(WLineSegment b)
{
return(b.GetIntersection(this));
}
/// <summary>Returns true if this point overlaps any part of the <pararef name='lineSegment'/>.</summary>
public bool Overlaps(WLineSegment lineSegment)
{
return(lineSegment.Overlaps(this));
}