Print Page - Entities within a closed polyline

I know this has to have been covered but I cant find anything on The Swamp or the interwebs via Google when I type the title to this post, except some LISP routines. I keep trying but from someone who comes from the OOP world, LISP is a garbled mess. So I'm looking for help in the form of .NET or even C++.

So what I want to do is find all the entities within a closed polyline from WCS. Any pointing in the right direction would be much appreciated.

Have you tried Editor.SelectWindow using the extents for a rectangular polyline
or Editor.SelectWindowPolygon using the vertices for a irregular shaped polyline
or does the polyline use arcs?

Thanks Jeff, and no I haven't tried using a selection window. Thought about that on my way in this morning.

Make sure the selectcing polygon, rectangular or not, is entirely visible on the current view before calling Editor.SelectWindowPolygon, or the returned SelectionSet may not be accurate. This is a known issue when using this method in code.

Thanks for the heads up.

Quote from: MexicanCustard on August 02, 2011, 05:25:46 PM

Thanks for the heads up.

Are you still with us? Have a look at this. Most of it comes from the AutoCAD .NET Developer's Guide, for doing what n.yuan said.

Code: [Select]

    public class Commands
    {
        Database db;
        Editor ed;
        public Commands()
        {
            Document doc = acApp.DocumentManager.MdiActiveDocument;
            db = doc.Database;
            ed = doc.Editor;
        }
        [CommandMethod("SelectInPolyline")]
        public void SelectInPolylineCmd()
        {
            PromptEntityOptions peo = new PromptEntityOptions("\nSelect a polyline: ");
            peo.SetRejectMessage("Only polylines accepted");
            peo.AddAllowedClass(typeof(Polyline), false);
            PromptEntityResult per = ed.GetEntity(peo);
            if(per.Status != PromptStatus.OK) return;
            ObjectId plId = per.ObjectId;
            
            using(Transaction tr = db.TransactionManager.StartTransaction())
            using(Point3dCollection vtcs = new Point3dCollection())
            {
                Polyline pl = (Polyline)tr.GetObject(plId, OpenMode.ForRead);
                ZoomExtents(pl.GeometricExtents);
                for(int i = 0; i < pl.NumberOfVertices; i++)
                    vtcs.Add(pl.GetPoint3dAt(i));
                tr.Commit();
                PromptSelectionResult psr = ed.SelectCrossingPolygon(vtcs);
                if(psr.Status != PromptStatus.OK) return;
                ObjectId[] ids = psr.Value.GetObjectIds();
                ed.SetImpliedSelection(ids.Where(id => id != plId).ToArray());                        
            }
        }
        // Lifted from 
        // http://docs.autodesk.com/ACD/2010/ENU/AutoCAD%20.NET%20Developer%27s%20Guide/files/WS1a9193826455f5ff2566ffd511ff6f8c7ca-4363.htm
        private void ZoomExtents(Extents3d extents)
        {
            // Get the current view
            using(ViewTableRecord acView = ed.GetCurrentView())
            {
                // Translate WCS coordinates to DCS
                Matrix3d matWCS2DCS =
                    Matrix3d.Rotation(
                        -acView.ViewTwist, acView.ViewDirection, acView.Target ) *
                    Matrix3d.Displacement(acView.Target - Point3d.Origin) *
                    Matrix3d.PlaneToWorld(acView.ViewDirection);
 
                // Calculate the ratio between the width and height of the current view
                double dViewRatio = (acView.Width / acView.Height);
 
                // Tranform the extents of the view
                extents.TransformBy(matWCS2DCS.Inverse());

                // Calculate the new width and height of the current view
                double dWidth = extents.MaxPoint.X - extents.MinPoint.X;
                double dHeight = extents.MaxPoint.Y - extents.MinPoint.Y;

                // Check to see if the new width fits in current window
                if(dWidth > dHeight * dViewRatio) 
                    dHeight = dWidth / dViewRatio;
            

                // Get the center of the view
                Point2d pNewCentPt = 
                    new Point2d(
                        (extents.MaxPoint.X + extents.MinPoint.X) * 0.5,
                        (extents.MaxPoint.Y + extents.MinPoint.Y) * 0.5 );

                // Resize the view
                acView.Height = dHeight;
                acView.Width = dWidth;

                // Set the center of the view
                acView.CenterPoint = pNewCentPt;
 
                // Set the current view
                ed.SetCurrentView(acView);
            }
        }
    }

No code, but "Point in boundary" seems to return a number of promising algorithms. You could start with a simple min/max box filter on the extents of the enclosing boundary PLINE, then iterate the point(s) of any passing entities through the algorithm.

kaefer, thanks for the code that looks promising.

Working on a Jig for the polyline. Everything with the jig was working great until I decide to give the user the option to make a rectangle. The rectangle isn't updated correctly in the Update method. Got a couple more things to try before posting my failure and asking for help.

TheSwamp

Code Red => .NET => Topic started by: MexicanCustard on August 01, 2011, 04:38:39 PM