//--------------------------------------------------------------------------------------------------
public static bool RenderEdge(IDrawingRenderer renderer, TopoDS_Edge edge, bool reverse, TopoDS_Face face)
{
var res = true;
reverse ^= edge.Orientation() == TopAbs_Orientation.TopAbs_REVERSED;
double first = 0, last = 0;
if (face != null)
{
var curve = BRep_Tool.CurveOnSurface(edge, new Geom_Plane(Ax3.XOY), new TopLoc_Location(), ref first, ref last);
if (curve == null)
{
return(false);
}
res &= RenderCurve(renderer, curve, first, last, reverse);
}
else
{
if (!(edge.TShape() is BRep_TEdge tedge))
{
return(res);
}
var curves = tedge.CurvesList();
if (reverse)
{
curves.Reverse();
}
foreach (var curveOnSurface in curves.OfType <BRep_CurveOnSurface>())
{
var curve = curveOnSurface.PCurve();
first = curveOnSurface.First();
last = curveOnSurface.Last();
res &= RenderCurve(renderer, curve, first, last, reverse);
}
}
return(res);
}
//--------------------------------------------------------------------------------------------------
void _ExportEdge(TopoDS_Edge edge, bool reverse, TopoDS_Face face)
{
reverse ^= edge.Orientation() == TopAbs_Orientation.TopAbs_REVERSED;
double first = 0, last = 0;
if (face != null)
{
var curve = BRep_Tool.CurveOnSurface(edge, new Geom_Plane(Ax3.XOY), new TopLoc_Location(), ref first, ref last);
if (curve == null)
{
return;
}
AddCurve(curve, reverse, first, last);
}
else
{
var tedge = edge.TShape() as BRep_TEdge;
if (tedge == null)
{
return;
}
var curves = tedge.CurvesList();
if (reverse)
{
curves.Reverse();
}
foreach (var curveOnSurface in curves.Cast <BRep_CurveOnSurface>())
{
var curve = curveOnSurface.PCurve();
first = curveOnSurface.First();
last = curveOnSurface.Last();
AddCurve(curve, reverse, first, last);
}
}
}
//--------------------------------------------------------------------------------------------------
public static bool ComputeAxisFromEdge(TopoDS_Face face, TopoDS_Edge edge, double parameter, out Ax1 axis)
{
axis = new Ax1();
// Get edge point and tangent
var adaptorEdge = edge.Adaptor();
var edgeFirst = adaptorEdge.FirstParameter();
var edgeLast = adaptorEdge.LastParameter();
var centerParam = parameter.Clamp(edgeFirst, edgeLast);
Pnt centerPoint = Pnt.Origin;
Vec edgeTangent = Vec.Zero;
adaptorEdge.D1(centerParam, ref centerPoint, ref edgeTangent);
if (edge.Orientation() == TopAbs_Orientation.TopAbs_REVERSED)
{
edgeTangent.Reverse();
}
// Get normal at point of edge
double first = 0, last = 0;
var curveOnSurface = BRep_Tool.CurveOnSurface(edge, face, ref first, ref last);
if (curveOnSurface == null)
{
return(false);
}
var paramNormalized = (centerParam - edgeFirst) / (edgeLast - edgeFirst);
var centerUV = curveOnSurface.Value(first + (last - first) * paramNormalized);
Vec faceNormal = Vec.Zero;
new BRepGProp_Face(face).Normal(centerUV.X, centerUV.Y, ref centerPoint, ref faceNormal);
axis = new Ax1(centerPoint, faceNormal.ToDir().Crossed(edgeTangent.ToDir()));
return(true);
}
/// <summary>
/// Searches for the longest edge of a shape, and find the longest parallel edge
/// </summary>
public static (TopoDS_Edge edge, Ax1?axis, TopoDS_Edge opEdge, Ax1?opAxis) FindLongestEdge(TopoDS_Shape shape)
{
TopoDS_Edge foundEdge = null;
Ax1? foundAxis = null;
TopoDS_Edge opEdge = null;
Ax1? opAxis = null;
// Find the longest edge to revolve around
double edgeLen = -1;
var edgeInfos = new List <(TopoDS_Edge edge, double len, Ax1 axis)>();
var edges = shape.Edges();
foreach (var edge in edges)
{
var brepAdaptor = new BRepAdaptor_Curve(edge);
if (brepAdaptor.GetGeomType() != GeomAbs_CurveType.GeomAbs_Line)
{
break;
}
var v1 = brepAdaptor.Value(brepAdaptor.FirstParameter());
var v2 = brepAdaptor.Value(brepAdaptor.LastParameter());
var len = v1.Distance(v2);
var axis = new Ax1(v1, new Vec(v1, v2).ToDir());
if (edge.Orientation() == TopAbs_Orientation.TopAbs_REVERSED)
{
axis.Reverse();
}
edgeInfos.Add((edge, len, axis));
if (foundEdge != null && foundEdge.IsSame(edge))
{
// Same edge with another orientation
if (foundEdge.Orientation() == TopAbs_Orientation.TopAbs_REVERSED &&
edge.Orientation() == TopAbs_Orientation.TopAbs_FORWARD)
{
// Prefer forward edges
foundEdge = edge;
}
continue;
}
if (len > edgeLen)
{
foundEdge = edge;
edgeLen = len;
foundAxis = axis;
}
}
if (foundAxis != null)
{
// Find opposite edge
edgeLen = -1;
foreach (var ei in edgeInfos)
{
if (ei.edge == foundEdge)
{
continue;
}
if (!ei.axis.IsParallel(foundAxis.Value, 0.00001))
{
continue;
}
if (ei.len > edgeLen)
{
opEdge = ei.edge;
edgeLen = ei.len;
opAxis = ei.axis;
}
}
}
return(foundEdge, foundAxis, opEdge, opAxis);
}