/// <summary>
/// Static version of InCentre function.
/// </summary>
public static C2DPoint GetInCentre(C2DPoint pt1, C2DPoint pt2, C2DPoint pt3)
{
// Set up a line to bisect the lines from 1 to 2 and 1 to 3
var Line1 = new C2DLine(pt1, pt2);
var Line2 = new C2DLine(pt1, pt3);
Line1.SetLength(Line2.GetLength());
var Line12Bisect = new C2DLine(pt1, pt3.GetMidPoint(Line1.GetPointTo()));
// Set up a line to bisect the lines from 2 to 1 and 2 to 3
var Line3 = new C2DLine(pt2, pt1);
var Line4 = new C2DLine(pt2, pt3);
Line3.SetLength(Line4.GetLength());
var Line34Bisect = new C2DLine(pt2, pt3.GetMidPoint(Line3.GetPointTo()));
// Now intersect the 2 lines and find the point.
var Int = new List <C2DPoint>();
// Add the intersection even if there isn't one (i.e. infinite lines)
bool B1 = true, B2 = true;
Line12Bisect.Crosses(Line34Bisect, Int, ref B1, ref B2, true);
Debug.Assert(Int.Count == 1);
return(Int[0]);
}
/// <summary>
/// Gets the point half way along the curve as a new object.
/// </summary>
public C2DPoint GetMidPoint()
{
Debug.Assert(IsValid(), "Invalid arc defined, cannot calculate midpoint");
// Make a line from the circle centre to the middle of the line
C2DPoint ptCentre = new C2DPoint(GetCircleCentre());
C2DPoint ptLineCentre = new C2DPoint(Line.GetMidPoint());
C2DLine CenToMid = new C2DLine(ptCentre, ptLineCentre);
if (CenToMid.vector.i == 0 && CenToMid.vector.j == 0)
{
// The centre of the line is the same as the centre of the circle
// i.e. this arc is 180 degrees or half a circle.
CenToMid.Set(Line);
CenToMid.SetPointFrom(ptLineCentre);
if (ArcOnRight)
{
CenToMid.vector.TurnRight();
}
else
{
CenToMid.vector.TurnLeft();
}
}
else
{
// extend it to the edge of the arc
CenToMid.SetLength(Radius);
// if the arc on the opposite side to the centre then reverse the line.
if (ArcOnRight == CentreOnRight)
{
CenToMid.vector.Reverse();
}
}
return(CenToMid.GetPointTo());
}
/// <summary>
/// Static version of InCentre function.
/// </summary>
public static C2DPoint GetInCentre(C2DPoint pt1, C2DPoint pt2, C2DPoint pt3)
{
// Set up a line to bisect the lines from 1 to 2 and 1 to 3
C2DLine Line1 = new C2DLine(pt1, pt2);
C2DLine Line2 = new C2DLine(pt1, pt3);
Line1.SetLength( Line2.GetLength() );
C2DLine Line12Bisect = new C2DLine( pt1, pt3.GetMidPoint( Line1.GetPointTo()));
// Set up a line to bisect the lines from 2 to 1 and 2 to 3
C2DLine Line3 = new C2DLine(pt2, pt1);
C2DLine Line4 = new C2DLine(pt2, pt3);
Line3.SetLength( Line4.GetLength() );
C2DLine Line34Bisect = new C2DLine(pt2, pt3.GetMidPoint(Line3.GetPointTo()));
// Now intersect the 2 lines and find the point.
List<C2DPoint> Int = new List<C2DPoint>();
// Add the intersection even if there isn't one (i.e. infinite lines)
bool B1 = true, B2 = true;
Line12Bisect.Crosses(Line34Bisect, Int, ref B1, ref B2, true);
Debug.Assert (Int.Count == 1);
return Int[0];
}
/// <summary>
/// Gets the point half way along the curve as a new object.
/// </summary>
public C2DPoint GetMidPoint()
{
Debug.Assert(IsValid(), "Invalid arc defined, cannot calculate midpoint");
// Make a line from the circle centre to the middle of the line
C2DPoint ptCentre = new C2DPoint(GetCircleCentre());
C2DPoint ptLineCentre = new C2DPoint(Line.GetMidPoint());
C2DLine CenToMid = new C2DLine(ptCentre, ptLineCentre);
if ( CenToMid.vector.i == 0 && CenToMid.vector.j == 0)
{
// The centre of the line is the same as the centre of the circle
// i.e. this arc is 180 degrees or half a circle.
CenToMid.Set(Line);
CenToMid.SetPointFrom( ptLineCentre );
if ( ArcOnRight )
CenToMid.vector.TurnRight();
else
CenToMid.vector.TurnLeft();
}
else
{
// extend it to the edge of the arc
CenToMid.SetLength( Radius );
// if the arc on the opposite side to the centre then reverse the line.
if ( ArcOnRight == CentreOnRight)
{
CenToMid.vector.Reverse();
}
}
return CenToMid.GetPointTo();
}