public Fraction Tangent(LineFr that) // tan(theta) = (m1 - m2)/(1 + (m1*m2))
{
if (isParallelTo(that))
{
return(Fraction.Zero);
}
if (IsVertical())
{
if (that.IsHorizontal())
{
return(-1);
}
return(Slope.Inverse());
}
if (that.IsVertical())
{
if (that.IsHorizontal())
{
return(-1);
}
return(Slope);
}
if (isPerpendicularTo(that))
{
return(-1);
}
return((Slope - that.Slope) / (1 + Slope * that.Slope));
}
public void SwapEndPoints()
{
var temp = StartPoint;
StartPoint = EndPoint;
EndPoint = temp;
Line = new LineFr(StartPoint, EndPoint);
}
public PointFr?Intersection(LineFr line)
{
var p = Line.Intersection(line);
if (p == null || !Contains((PointFr)p))
{
return(null);
}
return(p);
}
private Fraction XIntercept(LineFr that) // y = slope* x + constant: (b2 - b1) / (m1 - m2)
{
if (IsVertical())
{
return(Constant);
}
if (that.IsVertical())
{
return(that.Constant);
}
return((that.Constant - Constant) / (Slope - that.Slope));
}
public bool isPerpendicularTo(LineFr that)
{
if (IsVertical())
{
return(that.IsHorizontal());
}
if (that.IsVertical())
{
return(IsHorizontal());
}
return(Slope * that.Slope == -1);
}
private void MoveSweepLineTo(EventPoint ep) // Przesuń miotłę do nowego punktu zdarzenia
{
CurrentSweepPoint = ep.PointValue;
if (SweepLineValue == null)
{
throw new ArgumentException("Wartość SweepLineValue nie może być pusta podczas zmiany stanu miotły");
}
SweepLineValue = new LineFr(((LineFr)SweepLineValue).Slope, (PointFr)CurrentSweepPoint);
if (!OldSweepLineValues.ContainsKey((PointFr)CurrentSweepPoint))
{
OldSweepLineValues.Add((PointFr)CurrentSweepPoint, (LineFr)SweepLineValue);
}
}
public PointFr?Intersection(LineFr that)
{
if (Slope == that.Slope)
{
return(null);
}
var xInt = XIntercept(that);
if (IsVertical())
{
return(new PointFr(xInt, that.YIntercept(xInt)));
}
return(new PointFr(xInt, YIntercept(xInt)));
}
public bool IsRightOf(LineFr line)
{
if (line.Contains(this))
{
return(false);
}
if (line.IsHorizontal())
{
return(Y < line.YIntercept());
}
if (line.IsVertical())
{
return(X > line.XIntercept());
}
var linePointNullable = line.Intersection(LineFr.Vertical(Fraction.Zero));
if (linePointNullable == null)
{
throw new ArgumentException("Wartość linePoint nie może wynosić null");
}
var linePoint = (PointFr)linePointNullable;
var temp = new LineFr(this, linePoint);
if (Y < linePoint.Y)
{
if (line.Slope < 0) // a
{
return(temp.Slope < 0 && temp.Slope > line.Slope);
}
return(temp.Slope < 0 || temp.Slope > line.Slope); // b
}
if (Y > linePoint.Y)
{
if (line.Slope < 0) // c
{
return(temp.Slope >= 0 || temp.Slope < line.Slope);
}
return(temp.Slope >= 0 && temp.Slope < line.Slope); // d
}
return(IsRightOf(linePoint)); // 'this' ma taką samą współrzędną y jak 'linePoint'
}
public LineSegmentFr(PointFr start, PointFr end, bool LeftMostPointFirst = false)
{
if (start.Equals(end))
{
throw new ArgumentException("Nie można utworzyć odcinka, o dwóch takich samych punktach");
}
StartPoint = start;
EndPoint = end;
MaxX = start.X > end.X ? start.X : end.X;
MaxY = start.Y > end.Y ? start.Y : end.Y;
MinX = start.X < end.X ? start.X : end.X;
MinY = start.Y < end.Y ? start.Y : end.Y;
Line = new LineFr(start, end);
if (LeftMostPointFirst)
{
NormalizeEndPoints();
}
}
public bool IsLeftOf(LineFr line)
{
return(!line.Contains(this) && !IsRightOf(line));
}
public bool Intersects(LineFr line)
{
return(Intersection(line) != null);
}
public bool isParallelTo(LineFr that)
{
return(Slope == that.Slope);
}
public bool Intersects(LineFr that)
{
return(Slope != that.Slope);
}