/// <summary>
/// This method calculates the localizer line of the sourceFrame that can be drawn on the destinationFrame.
/// You should call the method CanDrawLocalizer prior to check if localizer calculation is valid on the two frames.
///
/// This method returns the line of common pixels where the two images intersect.
/// If the two images intersect, then it returns <code>true</code> and the out parameters are filled with values. Otherwise the method returns <code>false</code>
/// </summary>
/// <param name="sourceFrame">The geometry of the frame, that is viewed by the user</param>
/// <param name="destinationFrame">The geometry of the scout frame, where the localizer line should be drawn on</param>
/// <param name="startPoint">If the frames intersect, then this contains the start point of the localizer line in terms of pixels on destinationFrame</param>
/// <param name="endPoint">If the frames intersect, then this contains the end point of the localizer lin in terms of pixels on destinationFrame</param>
/// <returns></returns>
public static bool CalcualteIntersectionLocalizer(FrameGeometry sourceFrame, FrameGeometry destinationFrame, out Point2 startPoint, out Point2 endPoint)
{
double t; // coeficient of the plane-equation
double nA, nB, nC, nD, nP;
var lstProj = new List <Point3D>();
// initialize
startPoint = Point2.Origin;
endPoint = Point2.Origin;
// validation
if (destinationFrame.DirectionNormal.IsZero)
{
return(false);
}
nP = destinationFrame.DirectionNormal * destinationFrame.PointTopLeft;
nA = destinationFrame.DirectionNormal * sourceFrame.PointTopLeft;
nB = destinationFrame.DirectionNormal * sourceFrame.PointTopRight;
nC = destinationFrame.DirectionNormal * sourceFrame.PointBottomRight;
nD = destinationFrame.DirectionNormal * sourceFrame.PointBottomLeft;
// segment AB
if (Math.Abs(nB - nA) > Constants.Epsilon)
{
t = (nP - nA) / (nB - nA);
if (t > 0 && t <= 1)
{
lstProj.Add(sourceFrame.PointTopLeft + t * (sourceFrame.PointTopRight - sourceFrame.PointTopLeft));
}
}
// segment BC
if (Math.Abs(nC - nB) > Constants.Epsilon)
{
t = (nP - nB) / (nC - nB);
if (t > 0 && t <= 1)
{
lstProj.Add(sourceFrame.PointTopRight + t * (sourceFrame.PointBottomRight - sourceFrame.PointTopRight));
}
}
// segment CD
if (Math.Abs(nD - nC) > Constants.Epsilon)
{
t = (nP - nC) / (nD - nC);
if (t > 0 && t <= 1)
{
lstProj.Add(sourceFrame.PointBottomRight + t * (sourceFrame.PointBottomLeft - sourceFrame.PointBottomRight));
}
}
// segment DA
if (Math.Abs(nA - nD) > Constants.Epsilon)
{
t = (nP - nD) / (nA - nD);
if (t > 0 && t <= 1)
{
lstProj.Add(sourceFrame.PointBottomLeft + t * (sourceFrame.PointTopLeft - sourceFrame.PointBottomLeft));
}
}
// the destinationplane should have been crossed exactly two times
if (lstProj.Count != 2)
{
return(false);
}
// now back from 3D patient space to 2D pixel space
startPoint = destinationFrame.TransformPatientPointToImage(lstProj[0]).Round();
endPoint = destinationFrame.TransformPatientPointToImage(lstProj[1]).Round();
return(true);
}
