// return null if parent should be completely clipped.
// TODO: determine whether or not to use face boundary.
private static IFCAnyHandle ProcessClippingFace(ExporterIFC exporterIFC, CurveLoop outerBoundary, Plane boundaryPlane,
Plane extrusionBasePlane, XYZ extrusionDirection, IFCRange range, bool useFaceBoundary, IFCAnyHandle bodyItemHnd)
{
if (outerBoundary == null || boundaryPlane == null)
{
throw new Exception("Invalid face boundary.");
}
double clippingSlant = boundaryPlane.Normal.DotProduct(extrusionDirection);
if (useFaceBoundary)
{
if (MathUtil.IsAlmostZero(clippingSlant))
{
return(bodyItemHnd);
}
}
bool clipCompletely;
if (!IsInRange(range, outerBoundary, boundaryPlane, extrusionDirection, out clipCompletely))
{
return(clipCompletely ? null : bodyItemHnd);
}
if (MathUtil.IsAlmostZero(clippingSlant))
{
throw new Exception("Can't create clipping perpendicular to extrusion.");
}
IFCFile file = exporterIFC.GetFile();
XYZ scaledOrig = ExporterIFCUtils.TransformAndScalePoint(exporterIFC, boundaryPlane.Origin);
XYZ scaledNorm = ExporterIFCUtils.TransformAndScaleVector(exporterIFC, boundaryPlane.Normal);
XYZ scaledXDir = ExporterIFCUtils.TransformAndScaleVector(exporterIFC, boundaryPlane.XVec);
IFCAnyHandle planeAxisHnd = ExporterUtil.CreateAxis(file, scaledOrig, scaledNorm, scaledXDir);
IFCAnyHandle surfHnd = IFCInstanceExporter.CreatePlane(file, planeAxisHnd);
IFCAnyHandle clippedBodyItemHnd = null;
IFCAnyHandle halfSpaceHnd = null;
if (useFaceBoundary)
{
IFCAnyHandle boundedCurveHnd;
if (boundaryPlane != null)
{
XYZ projScaledOrigin = ExporterIFCUtils.TransformAndScalePoint(exporterIFC, extrusionBasePlane.Origin);
XYZ projScaledX = ExporterIFCUtils.TransformAndScaleVector(exporterIFC, extrusionBasePlane.XVec);
XYZ projScaledY = ExporterIFCUtils.TransformAndScaleVector(exporterIFC, extrusionBasePlane.YVec);
XYZ projScaledNorm = projScaledX.CrossProduct(projScaledY);
Plane projScaledPlane = new Plane(projScaledX, projScaledY, projScaledOrigin);
IList <UV> polylinePts = TransformAndProjectCurveLoopToPlane(exporterIFC, outerBoundary, projScaledPlane);
polylinePts.Add(polylinePts[0]);
boundedCurveHnd = ExporterUtil.CreatePolyline(file, polylinePts);
IFCAnyHandle boundedAxisHnd = ExporterUtil.CreateAxis(file, projScaledOrigin, projScaledNorm, projScaledX);
halfSpaceHnd = IFCInstanceExporter.CreatePolygonalBoundedHalfSpace(file, boundedAxisHnd, boundedCurveHnd, surfHnd, false);
}
else
{
throw new Exception("Can't create non-polygonal face boundary.");
}
}
else
{
halfSpaceHnd = IFCInstanceExporter.CreateHalfSpaceSolid(file, surfHnd, false);
}
if (halfSpaceHnd == null)
{
throw new Exception("Can't create clipping.");
}
clippedBodyItemHnd = IFCInstanceExporter.CreateBooleanClippingResult(file, IFCBooleanOperator.Difference,
bodyItemHnd, halfSpaceHnd);
return(clippedBodyItemHnd);
}