How to make two polylines eachother.

[MarkJamesRogolino]

Hello, everyone. Now I have to make two polylines (these are separated each other) touch.Is there a way to implement this process

[kerry_w_brown]

Please explain in detail.

[MarkJamesRogolino]

Hi, Kdub. Thanks for your reply. This is my problem.

If I have two poly lines in one document, I need to touch the two poly lines.
To do that, I have to stretch left polyline  to the right automatically. Is it possible?

[kerry_w_brown]

If you are sure the rectangular polylines will be in the orientation you show, 

perhaps :
change the RIGHT vertex locations.X of the left polyline to be the same as

the  LEFT vertex locations.X of the right polyline.

If your design differs, you will need to explain in detail.

added:
Any issues with the rectangles not being planar OR with the edges not being parallel will/may need to be handled.

>>> To do that, I have to stretch left polyline  to the right automatically. Is it possible? <<<

What do you imagine will initiale  initiate this functionality ?

edit 2023/02/25 : spelling

[MarkJamesRogolino]

Hi, Kdub. How can I move point3d runtime?

[kerry_w_brown]

You can't move  a point3D.

added : refer to your post : https://forums.autodesk.com/t5/net/how-to-get-an-objectid-of-a-point3d/m-p/11753625

You can relocate a Vertex :

https://help.autodesk.com/view/OARX/2023/ENU/?guid=OARX-ManagedRefGuide-Autodesk_AutoCAD_DatabaseSer...

I assume you know how to iterate the vertex 's of a polyline and test for the vertex index with the largest ( or smallest ) X value.

// - - - 

I don't know your use case, but another way to handle this is to ask the user to select the polyline segment to "move" and select the segment to align with.

You can determine the X value end vertex index of the endpoint of each segment and change the "moving" vertex locations accordingly.

added:

This may require some google work for you, but you will learn a lot.

Regards,

[MarkJamesRogolino]

Hello, kdub. Have a good weekend?

Thanks for your hint. But I have got this error.

This error cause is BlockTableRecord.AppendEntity(Polyline).

How can I solve this problem?

I think it does not requires Appendentity method. Right?

[kerry_w_brown]

Without seeing the code we'll only be guessing.

I'd guess you are trying to Add/Append a polyline twice into the database.

You may be able to debug this by adding breakpoints in the editor.

[MarkJamesRogolino]

Hi, kdub. Thanks for your help. I already move polyline's vertex correctly. But moved points are not on target polyline(target polyline segment's ison property is false).

Check function that one point is on polyline or not is als followings.
This function works correctly about other Polylines but does not work about moved polylines.

public static bool IsPointOnPolyline(Polyline pl, Point3d pt)           
        {
            bool isOn = false;
            for (int i = 0; i < pl.NumberOfVertices; i++)
            {
                Curve3d seg = null;
                SegmentType segType = pl.GetSegmentType(i);
                if (segType == SegmentType.Arc)
                    seg = pl.GetArcSegmentAt(i);
                else
                if (segType == SegmentType.Line)
                    seg = pl.GetLineSegmentAt(i);
                if (seg != null)
                {
                    isOn = seg.IsOn(pt);                    
                    if (isOn)
                        break;
                }
            }
            return isOn;
        }

Could you help me to solve this? I need to have the point3d lie on the target polyline.

[MarkJamesRogolino]

How to add this entity to blocktablerecord after moving point? Should I just save the document?

[kerry_w_brown]

I can't help without seeing ALL the code.

You seem to do this a lot, expecting others to resolve your problems without sufficient information.

[MarkJamesRogolino]

Sorry, my mistake. my code is followings.

public static bool checkTwoPlineTouch(Polyline pl1, Polyline pl2)            // this checks two polyline is close.
        {
            bool btch = false;

            int tchcnt = 0;
            for (int i = 0; i < pl2.NumberOfVertices; i++)
            {
                if (IsPointOnPolyline(pl1, pl2.GetPoint3dAt(i)))
                {
                    tchcnt++;
                }
            }
            if (tchcnt >= 2)
                btch = true;
            tchcnt = 0;
            if (!btch)
            {
                for (int i = 0; i < pl1.NumberOfVertices; i++)
                {
                    if (IsPointOnPolyline(pl2, pl1.GetPoint3dAt(i)))
                    {
                        tchcnt++;
                    }
                }
                if (tchcnt >= 2)
                    btch = true;
            }
            return btch;
        }
 public static bool IsPointOnPolyline(Polyline pl, Point3d pt)           // this returns point is on polyline or not.
        {
            bool isOn = false;
            for (int i = 0; i < pl.NumberOfVertices; i++)
            {
                Curve3d seg = null;
                SegmentType segType = pl.GetSegmentType(i);
                if (segType == SegmentType.Arc)
                    seg = pl.GetArcSegmentAt(i);
                else
                if (segType == SegmentType.Line)
                    seg = pl.GetLineSegmentAt(i);
                if (seg != null)
                {
                    isOn = seg.IsOn(pt);      
                    //isOn=seg.
                    if (isOn)
                        break;
                }
            }
            return isOn;
        }

Now moved point is lie on target polyline. But IsOnPolyline function returns false.

[kerry_w_brown]

It looks to me you've used

https://www.keanw.com/2012/01/testing-whether-a-point-is-on-an-autocad-polyline-using-net.html

This is an "Improved version"

https://through-the-interface.typepad.com/through_the_interface/2012/01/testing-whether-a-point-is-o...

Have you tested it by passing a polyline and a Point3d that you "KNOW" is exactly on the pline ??

//

Perhaps there is a rounding issue with the Point3d axis values ?

I haven't checked your code ( or the copy ) , just giving options for you to check.

[MarkJamesRogolino]

Thanks, I used https://www.keanw.com/2012/01/testing-whether-a-point-is-on-an-autocad-polyline-using-net.html.

But how can I get Curve from polyline?

IsPointOnCurveGDAP and IsPointOnCurveGCP function use Curve entity as a parameter.

[_gile]

---

@MarkJamesRogolino  a écrit :

But how can I get Curve from polyline?

---

The Polyline class is derived from the Curve one, so all Curve members apply to Polyline. You should learn Inheritance which is one of the basics of OOP.

[MarkJamesRogolino]

I know already Inheritence of OOP. I mean how to get Curve(line segment) from polyline entity.

public static bool IsPointOnPolyline(Polyline pl, Point3d pt)           // this returns point is on polyline or not.
        {
            
            bool isOn = false;
            for (int i = 0; i < pl.NumberOfVertices; i++)
            {
                Curve3d seg = null;
                SegmentType segType = pl.GetSegmentType(i);
                if (segType == SegmentType.Arc)
                    seg = pl.GetArcSegmentAt(i);
                else
                if (segType == SegmentType.Line)
                    seg = pl.GetLineSegmentAt(i);
                if (seg != null)
                {
                    isOn = seg.IsOn(pt);      
                    //isOn= IsPointOnCurveGDAP(seg, pt);
                    if (isOn)
                        break;
                }
            }
            return isOn;
        }
private bool IsPointOnCurveGCP(Curve cv, Point3d pt)
        {
            try
            {
                Point3d p = cv.GetClosestPointTo(pt, false);
                return (p - pt).Length <= Tolerance.Global.EqualPoint;
            }
            catch { }
            return false;
        }

Here seg should be Curve type.

[_gile]

Are not you confusing Curve and Curve3d?

Both methods you show work with a Polyline.

IsPointOnPolyline(pline, point) should return the same result as IsPointOnCurveGCP(pline, point)

[MarkJamesRogolino]

Hi, gile. In my opinion cv of IsPointOnCurveGCP(Curve cv, point) function is linesegment of pline of IsPointOnPolyline(pline, point). I want to get  curve as a linesegment of pline.

[kerry_w_brown]

@MarkJamesRogolino 

>>> I want to get  curve as a linesegment of pline. <<<

Sorry, I can't understand those requitements.

See if this helps your understanding :

// (C) CodeHimBelonga: kdub 2023/03/03
//
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
using System;

//using Kdub.Common;
using AcadApp = Autodesk.AutoCAD.ApplicationServices.Core.Application;

[assembly: CommandClass(typeof(TouchingPolylines.TestCommands_02))]

namespace TouchingPolylines
{
   public class TestCommands_02
   {
      private static Document _doc => AcadApp.DocumentManager.MdiActiveDocument;
      private static Database _db => _doc.Database;
      private static Editor _ed => _doc.Editor;

      public static void WriteMessage(string msg) => _ed.WriteMessage(msg);


      [CommandMethod("plSegment")]
      public static void PlineSegment()
      {
         PromptEntityOptions peo = new PromptEntityOptions("\nSelect a Polyline Segment: ");
         peo.SetRejectMessage("\nMust be a Polyline...");
         peo.AddAllowedClass(typeof(Polyline), true);
         PromptEntityResult per = _ed.GetEntity(peo);
         
         if (per.Status == PromptStatus.Cancel) return;
         using (Transaction tr = _doc.TransactionManager.StartTransaction())
         {
            var pline = (Polyline)per.ObjectId.GetObject(OpenMode.ForRead);
            var wcsPickedPoint = per.PickedPoint.TransformBy(_ed.CurrentUserCoordinateSystem);
            var pointOnPline = pline.GetClosestPointTo(wcsPickedPoint, false);
            var segmentIndex = (int)pline.GetParameterAtPoint(pointOnPline);

            if (pline.GetSegmentType(segmentIndex) == SegmentType.Line)
            {
               LineSegment2d segment = pline.GetLineSegment2dAt(segmentIndex);
               _ed.WriteMessage($"\nsegmentIndex: {segmentIndex}\n");
               _ed.WriteMessage($"segment Length: {segment.Length}\n");
               _ed.WriteMessage($"Angle: {( segment.Direction.Angle * 180 / Math.PI )}°\n" );
               _ed.WriteMessage($"Startpoint: {(segment.StartPoint)}\n");
            }
            else
            {
               _ed.WriteMessage($"\nsegment Type: {pline.GetSegmentType(segmentIndex)}\n");
            }
            tr.Commit();
         }
      }
   }
}

Regards,

[MarkJamesRogolino]

Thanks, kdub. I mean I should know one point is lie on one linesegment. I enclosed my working video.

As you can see in my video I moved two points to one Polyline. But my code returns two polylines are not touched eachother. Followings are my code. 

BlockTable acBlkTbl;
acBlkTbl = acCurrTrans.GetObject(db.BlockTableId, OpenMode.ForWrite) as BlockTable;
BlockTableRecord acBlkTblRec;
acBlkTblRec = acCurrTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],OpenMode.ForWrite) as BlockTableRecord;
Point3d acPt3d = new Point3d(right1.X, 0, 0);
Vector3d acVec3d = acPt3d.GetVectorTo(new Point3d(left2.X, 0, 0));
for (int i = 0; i < pln1.NumberOfVertices; i++)
{
    Point3d pt = pln1.GetPoint3dAt(i);
    if (pt.X == right1.X)
    {
       pln1.SetPointAt(i, new Point2d(left2.X, pt.Y));
    }
}
bool istch = NBCrelate.checkTwoPlineTouch(pln2, pln1);
if (istch)
  Application.ShowAlertDialog("Two Polyline touched");
public static bool checkTwoPlineTouch(Polyline pl1, Polyline pl2)            // this checks two polyline is close.
        {
            bool btch = false;

            int tchcnt = 0;
            for (int i = 0; i < pl2.NumberOfVertices; i++)
            {
                if (IsPointOnPolyline(pl1, pl2.GetPoint3dAt(i)))
                {
                    tchcnt++;
                }
            }
            if (tchcnt >= 2)
                btch = true;
            tchcnt = 0;
            if (!btch)
            {
                for (int i = 0; i < pl1.NumberOfVertices; i++)
                {
                    if (IsPointOnPolyline(pl2, pl1.GetPoint3dAt(i)))
                    {
                        tchcnt++;
                    }
                }
                if (tchcnt >= 2)
                    btch = true;
            }
            return btch;
        }
public static bool IsPointOnPolyline(Polyline pl, Point3d pt)           // this returns point is on polyline or not.
        {            
            bool isOn = false;
            for (int i = 0; i < pl.NumberOfVertices; i++)
            {
                Curve3d seg = null;
                Curve seg1 = null;
                SegmentType segType = pl.GetSegmentType(i);
                if (segType == SegmentType.Arc)
                    seg = pl.GetArcSegmentAt(i);
                else
                if (segType == SegmentType.Line)
                    seg = pl.GetLineSegmentAt(i);
                    //seg1 = pl.GetLineSegment2dAt(i);
                if (seg != null)
                {
                    //isOn = seg.IsOn(pt);      
                    isOn= IsPointOnCurveGDAP(seg, pt);
                    if (isOn)
                        break;
                }
            }
            return isOn;
        }

I saw moved Polyline's Point is equal to target polylines's left vertex X coordinate.

But IsPointOnPolyline function does not return true. I dont know cause. Could you tell me?