/// <summary>
/// True if part of this line is above the other. Returns the point
/// on this and on the other.
/// </summary>
/// <param name="Other"></param>
/// <param name="dVerticalDistance"></param>
/// <param name="ptOnThis"></param>
/// <param name="ptOnOther"></param>
/// <returns></returns>
public bool OverlapsAbove(C2DLine Other, ref double dVerticalDistance,
C2DPoint ptOnThis, C2DPoint ptOnOther)
{
// Get the 2 points for both lines
C2DPoint OtherTo = new C2DPoint(Other.point.x + Other.vector.i, Other.point.y + Other.vector.j);
C2DPoint ThisTo = new C2DPoint(point.x + vector.i, point.y + vector.j);
// Make an interval for both in the x plane
CInterval iThis = new CInterval( point.x, point.x);
iThis.ExpandToInclude( ThisTo.x );
CInterval iOther = new CInterval( Other.point.x, Other.point.x);
iOther.ExpandToInclude( OtherTo.x );
// This is an interval for the overlap between the 2
CInterval iOverlap = new CInterval();
// If there is an overlap...
if (iThis.Overlaps(iOther, iOverlap))
{
double dThisYMin;
double dThisYMax;
double dOtherYMin;
double dOtherYMax;
// If the line is vertical then y at the x min / max can be set to the ends of the line.
if (vector.i == 0)
{
dThisYMin = point.y;
dThisYMax = ThisTo.y;
}
else // otherwise, caluclate the y values at the interval ends
{
dThisYMin = GetY(iOverlap.dMin);
dThisYMax = GetY(iOverlap.dMax);
}
// Now do the same for the other line
if (Other.vector.i == 0)
{
dOtherYMin = Other.point.y;
dOtherYMax = OtherTo.y;
}
else
{
dOtherYMin = Other.GetY(iOverlap.dMin);
dOtherYMax = Other.GetY(iOverlap.dMax);
}
// Now find the distance between the 2 at the ends
double dDistMin = dThisYMin - dOtherYMin;
double dDistMax = dThisYMax - dOtherYMax;
// If they are both > 0 then no intersection
if ( (dDistMin > 0) && (dDistMax > 0))
{
dDistMin = Math.Abs( dDistMin);
dDistMax = Math.Abs(dDistMax);
// find which one is smallest
if ( dDistMin > dDistMax)
{
dVerticalDistance = dDistMax; // distance at the max is smallest
ptOnThis.x = iOverlap.dMax;
ptOnThis.y = dThisYMax;
ptOnOther.x = iOverlap.dMax;
ptOnOther.y = dOtherYMax;
}
else
{
dVerticalDistance = dDistMin; // distance at the min is smallest
ptOnThis.x = iOverlap.dMin;
ptOnThis.y = dThisYMin;
ptOnOther.x = iOverlap.dMin;
ptOnOther.y = dOtherYMin;
}
return true;
}
else if ( (dDistMin < 0) && (dDistMax < 0)) // This is below.
{
return false;
}
else
{
// find the intersection.
dVerticalDistance = 0;
C2DPointSet pts = new C2DPointSet();
if(this.Crosses(Other, pts))
{
ptOnThis = pts[0];
ptOnOther = ptOnThis;
}
else
{
Debug.Assert(false);
}
}
return true;
}
else
{
return false;
}
}
/// <summary>
/// True if part of this line is above the other. Returns the point
/// on this and on the other.
/// </summary>
/// <param name="Other"></param>
/// <param name="dVerticalDistance"></param>
/// <param name="ptOnThis"></param>
/// <param name="ptOnOther"></param>
/// <returns></returns>
public bool OverlapsAbove(C2DLine Other, ref double dVerticalDistance,
C2DPoint ptOnThis, C2DPoint ptOnOther)
{
// Get the 2 points for both lines
var OtherTo = new C2DPoint(Other.point.x + Other.vector.i, Other.point.y + Other.vector.j);
var ThisTo = new C2DPoint(point.x + vector.i, point.y + vector.j);
// Make an interval for both in the x plane
var iThis = new CInterval(point.x, point.x);
iThis.ExpandToInclude(ThisTo.x);
var iOther = new CInterval(Other.point.x, Other.point.x);
iOther.ExpandToInclude(OtherTo.x);
// This is an interval for the overlap between the 2
var iOverlap = new CInterval();
// If there is an overlap...
if (iThis.Overlaps(iOther, iOverlap))
{
double dThisYMin;
double dThisYMax;
double dOtherYMin;
double dOtherYMax;
// If the line is vertical then y at the x min / max can be set to the ends of the line.
if (vector.i == 0)
{
dThisYMin = point.y;
dThisYMax = ThisTo.y;
}
else // otherwise, caluclate the y values at the interval ends
{
dThisYMin = GetY(iOverlap.dMin);
dThisYMax = GetY(iOverlap.dMax);
}
// Now do the same for the other line
if (Other.vector.i == 0)
{
dOtherYMin = Other.point.y;
dOtherYMax = OtherTo.y;
}
else
{
dOtherYMin = Other.GetY(iOverlap.dMin);
dOtherYMax = Other.GetY(iOverlap.dMax);
}
// Now find the distance between the 2 at the ends
var dDistMin = dThisYMin - dOtherYMin;
var dDistMax = dThisYMax - dOtherYMax;
// If they are both > 0 then no intersection
if ((dDistMin > 0) && (dDistMax > 0))
{
dDistMin = Math.Abs(dDistMin);
dDistMax = Math.Abs(dDistMax);
// find which one is smallest
if (dDistMin > dDistMax)
{
dVerticalDistance = dDistMax; // distance at the max is smallest
ptOnThis.x = iOverlap.dMax;
ptOnThis.y = dThisYMax;
ptOnOther.x = iOverlap.dMax;
ptOnOther.y = dOtherYMax;
}
else
{
dVerticalDistance = dDistMin; // distance at the min is smallest
ptOnThis.x = iOverlap.dMin;
ptOnThis.y = dThisYMin;
ptOnOther.x = iOverlap.dMin;
ptOnOther.y = dOtherYMin;
}
return(true);
}
else if ((dDistMin < 0) && (dDistMax < 0)) // This is below.
{
return(false);
}
else
{
// find the intersection.
dVerticalDistance = 0;
var pts = new C2DPointSet();
if (this.Crosses(Other, pts))
{
ptOnThis = pts[0];
ptOnOther = ptOnThis;
}
else
{
Debug.Assert(false);
}
}
return(true);
}
else
{
return(false);
}
}
