topic Re: How to find the coordinates of a line parallel to another on the same layer in .NET Forum

How to find the coordinates of a line parallel to another on the same layer

mecoman6GF27 — Fri, 31 Dec 2021 17:58:36 GMT

Hi everyone.

How could I do to identify the start and end coordinates of the parallel line closest to another and which are on the same layer?

Thanks a lot, bye.

Re: How to find the coordinates of a line parallel to another on the same layer

hosneyalaa — Fri, 31 Dec 2021 18:34:14 GMT

I think this will help you

https://forums.autodesk.com/t5/net/parallel-loop/m-p/3726470

Re: How to find the coordinates of a line parallel to another on the same layer

_gile — Sat, 01 Jan 2022 11:08:16 GMT

Hi,

You can try something like this:

[CommandMethod("FINDPARALLEL")] public static void FindClosestParallelLineCmd() { var doc = Application.DocumentManager.MdiActiveDocument; var db = doc.Database; var ed = doc.Editor; var options = new PromptEntityOptions("\nSelect Line: "); options.SetRejectMessage("Must be a Line."); options.AddAllowedClass(typeof(Line), true); var result = ed.GetEntity(options); if (result.Status != PromptStatus.OK) return; using (var tr = db.TransactionManager.StartTransaction()) { var source = (Line)tr.GetObject(result.ObjectId, OpenMode.ForRead); if (TryFindParallelLine(source, tr, out LineSegment3d line)) { ed.WriteMessage("\nStart point: {0:0.00} End point: {1:0.00}", line.StartPoint, line.EndPoint); } else { ed.WriteMessage("\nNone parallel line"); } tr.Commit(); } } static bool TryFindParallelLine(Line source, Transaction tr, out LineSegment3d line) { string layer = source.Layer; var segment = new LineSegment3d(source.StartPoint, source.EndPoint); var direction = segment.Direction; var segments = ((BlockTableRecord)tr.GetObject(source.OwnerId, OpenMode.ForRead)) .Cast<ObjectId>() .Where(id => id != source.ObjectId && id.ObjectClass.DxfName == "LINE") .Select(id => (Line)tr.GetObject(id, OpenMode.ForRead)) .Where(l => l.Layer == layer) .Select(l => new LineSegment3d(l.StartPoint, l.EndPoint)) .Where(s => s.Direction.IsParallelTo(direction)); if (segments.Any()) { line = segments.Aggregate((s1, s2) => (s1.GetDistanceTo(segment) < s2.GetDistanceTo(segment)) ? s1 : s2); return true; } else { line = null; return false; } }

Re: How to find the coordinates of a line parallel to another on the same layer

mecoman6GF27 — Mon, 03 Jan 2022 10:53:07 GMT

Hi, thank you so much for your help.

Your code works perfectly but I asked myself: how can I find the perpendicular distance between the two parallel lines?

I tried like this:

ed.WriteMessage (vbLf & "Perpendicular distance beetwen line1 and line2:" & line.StartPoint.DistanceTo (source.GetClosestPointTo (line.StartPoint, False)))

What I have written only works in three cases:

1. when the two lines are inclined at a certain angle;

2. when the two lines have the same length;

3. when I select the longest line.

If the two lines, horizontal or vertical, have a different length and I select the shorter line, I get the distance between points A and C and not the perpendicular distance between the two lines.

Where do you think I'm wrong?

Thanks a lot, bye.

Re: How to find the coordinates of a line parallel to another on the same layer

_gile — Mon, 03 Jan 2022 12:35:36 GMT

As you certainly noticed, the code uses the LineSegment3d type which exposes a GetDistanceTo method. This method is used to find the closest parallel line.

[CommandMethod("FINDPARALLEL")] public static void FindClosestParallelLineCmd() { var doc = Application.DocumentManager.MdiActiveDocument; var db = doc.Database; var ed = doc.Editor; var options = new PromptEntityOptions("\nSelect Line: "); options.SetRejectMessage("Must be a Line."); options.AddAllowedClass(typeof(Line), true); var result = ed.GetEntity(options); if (result.Status != PromptStatus.OK) return; using (var tr = db.TransactionManager.StartTransaction()) { var source = (Line)tr.GetObject(result.ObjectId, OpenMode.ForRead); if (TryFindParallelLine(source, tr, out LineSegment3d line, out double distance)) { ed.WriteMessage( "\nStart point: {0:0.00} End point: {1:0.00}\nDistance = {2:0.00}", line.StartPoint, line.EndPoint, distance); } else { ed.WriteMessage("\nNone parallel line"); } tr.Commit(); } } static bool TryFindParallelLine(Line source, Transaction tr, out LineSegment3d line, out double distance) { string layer = source.Layer; var segment = new LineSegment3d(source.StartPoint, source.EndPoint); var direction = segment.Direction; var segments = ((BlockTableRecord)tr.GetObject(source.OwnerId, OpenMode.ForRead)) .Cast<ObjectId>() .Where(id => id != source.ObjectId && id.ObjectClass.DxfName == "LINE") .Select(id => (Line)tr.GetObject(id, OpenMode.ForRead)) .Where(l => l.Layer == layer) .Select(l => new LineSegment3d(l.StartPoint, l.EndPoint)) .Where(s => s.Direction.IsParallelTo(direction)); if (segments.Any()) { line = segments.Aggregate((s1, s2) => (s1.GetDistanceTo(segment) < s2.GetDistanceTo(segment)) ? s1 : s2); distance = line.GetDistanceTo(segment); return true; } else { line = null; distance = -1.0; return false; } }

Re: How to find the coordinates of a line parallel to another on the same layer

mecoman6GF27 — Mon, 03 Jan 2022 15:38:50 GMT

Hi, thank you so much for your help.

Bye.