Creating the smallest possible rectangle around 2D AutoCAD geometry using .NET

csharp · 发表于 2014-5-8 15:41:27

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[ 本帖最后由 csharp 于 2014-5-15 10:12 编辑 ]\n\n[ 本帖最后由 csharp 于 2014-5-15 10:11 编辑 ]\n\n[ 本帖最后由 csharp 于 2014-5-9 06:53 编辑 ]\n\n[url=http://through-the-interface.typepad.com/through_the_interface/2012/11/creating-the-smallest-possible-rectangle-around-2d-autocad-geometry-using-net.html]http://through-the-interface.typepad.com/through_the_interface/2012/11/creating-the-smallest-possible-rectangle-around-2d-autocad-geometry-using-net.html[/url]
Creating the smallest possible rectangle around 2D AutoCAD geometry using .NET

There was a follow-up comment on this previous post, requesting that it also create a rectangular boundary around selected geometry. This is a much simpler problem to solve that dealing with a minimum enclosing circle, so I was happy enough to oblige. :-)

Rather than duplicate code from the previous implement, I went ahead and generalised it to contain a core set of functions that get called from different commands: MEC in the existing case where circular boundaries are required and MER for the new case of a rectangular polyline boundary.

I’ve also adjusted the prompts and code to be more general – including renaming the system variable to ENCLOSINGBOUNDARYBUFFER, although I only tested via the fallback USERI1 variable – and it all seems to work as expected.

Here’s the updated C# code:

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.Geometry;
using System.Collections.Generic;
using System.Linq;
using System;
namespace MinimumEnclosingBoundary
{
public class Commands
{
[CommandMethod("MER", CommandFlags.UsePickSet)]
public void MinimumEnclosingRectangle()
{
MinimumEnclosingBoundary(false);
}
[CommandMethod("MEC", CommandFlags.UsePickSet)]
public void MinimumEnclosingCircle()
{
MinimumEnclosingBoundary();
}
public void MinimumEnclosingBoundary(
bool circularBoundary = true
)
{
Document doc =
Application.DocumentManager.MdiActiveDocument;
Database db = doc.Database;
Editor ed = doc.Editor;
// Ask user to select entities
PromptSelectionOptions pso =
new PromptSelectionOptions();
pso.MessageForAdding = "\nSelect objects to enclose: ";
pso.AllowDuplicates = false;
pso.AllowSubSelections = true;
pso.RejectObjectsFromNonCurrentSpace = true;
pso.RejectObjectsOnLockedLayers = false;
PromptSelectionResult psr = ed.GetSelection(pso);
if (psr.Status != PromptStatus.OK)
return;
bool oneBoundPerEnt = false;
if (psr.Value.Count > 1)
{
PromptKeywordOptions pko =
new PromptKeywordOptions(
"\nMultiple objects selected: create " +
"individual boundaries around each one?"
);
pko.AllowNone = true;
pko.Keywords.Add("Yes");
pko.Keywords.Add("No");
pko.Keywords.Default = "No";
PromptResult pkr = ed.GetKeywords(pko);
if (pkr.Status != PromptStatus.OK)
return;
oneBoundPerEnt = (pkr.StringResult == "Yes");
}
// There may be a SysVar defining the buffer
// to add to our radius
double buffer = 0.0;
try
{
object bufvar =
Application.GetSystemVariable(
"ENCLOSINGBOUNDARYBUFFER"
);
if (bufvar != null)
{
short bufval = (short)bufvar;
buffer = bufval / 100.0;
}
}
catch
{
object bufvar =
Application.GetSystemVariable("USERI1");
if (bufvar != null)
{
short bufval = (short)bufvar;
buffer = bufval / 100.0;
}
}
// Get the current UCS
CoordinateSystem3d ucs =
ed.CurrentUserCoordinateSystem.CoordinateSystem3d;
// Collect points on the component entities
Point3dCollection pts = new Point3dCollection();
Transaction tr =
db.TransactionManager.StartTransaction();
using (tr)
{
BlockTableRecord btr =
(BlockTableRecord)tr.GetObject(
db.CurrentSpaceId,
OpenMode.ForWrite
);
for (int i = 0; i < psr.Value.Count; i++)
{
Entity ent =
(Entity)tr.GetObject(
psr.Value[i].ObjectId,
OpenMode.ForRead
);
// Collect the points for each selected entity
Point3dCollection entPts = CollectPoints(tr, ent);
foreach (Point3d pt in entPts)
{
/*
* Create a DBPoint, for testing purposes
*
DBPoint dbp = new DBPoint(pt);
btr.AppendEntity(dbp);
tr.AddNewlyCreatedDBObject(dbp, true);
*/
pts.Add(pt);
}
// Create a boundary for each entity (if so chosen) or
// just once after collecting all the points
if (oneBoundPerEnt || i == psr.Value.Count - 1)
{
try
{
Entity bnd =
(circularBoundary ?
CircleFromPoints(pts, ucs, buffer) :
RectangleFromPoints(pts, ucs, buffer)
);
btr.AppendEntity(bnd);
tr.AddNewlyCreatedDBObject(bnd, true);
}
catch
{
ed.WriteMessage(
"\nUnable to calculate enclosing boundary."
);
}
pts.Clear();
}
}
tr.Commit();
}
}
private Point3dCollection CollectPoints(
Transaction tr, Entity ent
)
{
// The collection of points to populate and return
Point3dCollection pts = new Point3dCollection();
// We'll start by checking a block reference for
// attributes, getting their bounds and adding
// them to the point list. We'll still explode
// the BlockReference later, to gather points
// from other geometry, it's just that approach
// doesn't work for attributes (we only get the
// AttributeDefinitions, which don't have bounds)
BlockReference br = ent as BlockReference;
if (br != null)
{
foreach (ObjectId arId in br.AttributeCollection)
{
DBObject obj = tr.GetObject(arId, OpenMode.ForRead);
if (obj is AttributeReference)
{
AttributeReference ar = (AttributeReference)obj;
ExtractBounds(ar, pts);
}
}
}
// If we have a curve - other than a polyline, which
// we will want to explode - we'll get points along
// its length
Curve cur = ent as Curve;
if (cur != null &&
!(cur is Polyline ||
cur is Polyline2d ||
cur is Polyline3d))
{
// Two points are enough for a line, we'll go with
// a higher number for other curves
int segs = (ent is Line ? 2 : 20);
double param = cur.EndParam - cur.StartParam;
for (int i = 0; i < segs; i++)
{
try
{
Point3d pt =
cur.GetPointAtParameter(
cur.StartParam + (i * param / (segs - 1))
);
pts.Add(pt);
}
catch { }
}
}
else if (ent is DBPoint)
{
// Points are easy
pts.Add(((DBPoint)ent).Position);
}
else if (ent is DBText)
{
// For DBText we use the same approach as
// for AttributeReferences
ExtractBounds((DBText)ent, pts);
}
else if (ent is MText)
{
// MText is also easy - you get all four corners
// returned by a function. That said, the points
// are of the MText's box, so may well be different
// from the bounds of the actual contents
MText txt = (MText)ent;
Point3dCollection pts2 = txt.GetBoundingPoints();
foreach (Point3d pt in pts2)
{
pts.Add(pt);
}
}
else if (ent is Face)
{
Face f = (Face)ent;
try
{
for (short i = 0; i < 4; i++)
{
pts.Add(f.GetVertexAt(i));
}
}
catch { }
}
else if (ent is Solid)
{
Solid sol = (Solid)ent;
try
{
for (short i = 0; i < 4; i++)
{
pts.Add(sol.GetPointAt(i));
}
}
catch { }
}
else
{
// Here's where we attempt to explode other types
// of object
DBObjectCollection oc = new DBObjectCollection();
try
{
ent.Explode(oc);
if (oc.Count > 0)
{
foreach (DBObject obj in oc)
{
Entity ent2 = obj as Entity;
if (ent2 != null && ent2.Visible)
{
foreach (Point3d pt in CollectPoints(tr, ent2))
{
pts.Add(pt);
}
}
obj.Dispose();
}
}
}
catch { }
}
return pts;
}
private void ExtractBounds(
DBText txt, Point3dCollection pts
)
{
// We have a special approach for DBText and
// AttributeReference objects, as we want to get
// all four corners of the bounding box, even
// when the text or the containing block reference
// is rotated
if (txt.Bounds.HasValue && txt.Visible)
{
// Create a straight version of the text object
// and copy across all the relevant properties
// (stopped copying AlignmentPoint, as it would
// sometimes cause an eNotApplicable error)
// We'll create the text at the WCS origin
// with no rotation, so it's easier to use its
// extents
DBText txt2 = new DBText();
txt2.Normal = Vector3d.ZAxis;
txt2.Position = Point3d.Origin;
// Other properties are copied from the original
txt2.TextString = txt.TextString;
txt2.TextStyleId = txt.TextStyleId;
txt2.LineWeight = txt.LineWeight;
txt2.Thickness = txt2.Thickness;
txt2.HorizontalMode = txt.HorizontalMode;
txt2.VerticalMode = txt.VerticalMode;
txt2.WidthFactor = txt.WidthFactor;
txt2.Height = txt.Height;
txt2.IsMirroredInX = txt2.IsMirroredInX;
txt2.IsMirroredInY = txt2.IsMirroredInY;
txt2.Oblique = txt.Oblique;
// Get its bounds if it has them defined
// (which it should, as the original did)
if (txt2.Bounds.HasValue)
{
Point3d maxPt = txt2.Bounds.Value.MaxPoint;
// Place all four corners of the bounding box
// in an array
Point2d[] bounds =
new Point2d[] {
Point2d.Origin,
new Point2d(0.0, maxPt.Y),
new Point2d(maxPt.X, maxPt.Y),
new Point2d(maxPt.X, 0.0)
};
// We're going to get each point's WCS coordinates
// using the plane the text is on
Plane pl = new Plane(txt.Position, txt.Normal);
// Rotate each point and add its WCS location to the
// collection
foreach (Point2d pt in bounds)
{
pts.Add(
pl.EvaluatePoint(
pt.RotateBy(txt.Rotation, Point2d.Origin)
)
);
}
}
}
}
private Entity RectangleFromPoints(
Point3dCollection pts, CoordinateSystem3d ucs, double buffer
)
{
// Get the plane of the UCS
Plane pl = new Plane(ucs.Origin, ucs.Zaxis);
// We will project these (possibly 3D) points onto
// the plane of the current UCS, as that's where
// we will create our circle
// Project the points onto it
List<;Point2d> pts2d = new List<;Point2d>(pts.Count);
for (int i = 0; i < pts.Count; i++)
{
pts2d.Add(pl.ParameterOf(pts[i]));
}
// Assuming we have some points in our list...
if (pts.Count > 0)
{
// Set the initial min and max values from the first entry
double minX = pts2d[0].X,
maxX = minX,
minY = pts2d[0].Y,
maxY = minY;
// Perform a single iteration to extract the min/max X and Y
for (int i = 1; i < pts2d.Count; i++)
{
Point2d pt = pts2d[i];
if (pt.X < minX) minX = pt.X;
if (pt.X > maxX) maxX = pt.X;
if (pt.Y < minY) minY = pt.Y;
if (pt.Y > maxY) maxY = pt.Y;
}
// Our final buffer amount will be the percentage of the
// smallest of the dimensions
double buf =
Math.Min(maxX - minX, maxY - minY) * buffer;
// Apply the buffer to our point ordinates
minX -= buf;
minY -= buf;
maxX += buf;
maxY += buf;
// Create the boundary points
Point2d pt0 = new Point2d(minX, minY),
pt1 = new Point2d(minX, maxY),
pt2 = new Point2d(maxX, maxY),
pt3 = new Point2d(maxX, minY);
// Finally we create the polyline
var p = new Polyline(4);
p.Normal = pl.Normal;
p.AddVertexAt(0, pt0, 0, 0, 0);
p.AddVertexAt(1, pt1, 0, 0, 0);
p.AddVertexAt(2, pt2, 0, 0, 0);
p.AddVertexAt(3, pt3, 0, 0, 0);
p.Closed = true;
return p;
}
return null;
}
private Entity CircleFromPoints(
Point3dCollection pts, CoordinateSystem3d ucs, double buffer
)
{
// Get the plane of the UCS
Plane pl = new Plane(ucs.Origin, ucs.Zaxis);
// We will project these (possibly 3D) points onto
// the plane of the current UCS, as that's where
// we will create our circle
// Project the points onto it
List<;Point2d> pts2d = new List<;Point2d>(pts.Count);
for (int i = 0; i < pts.Count; i++)
{
pts2d.Add(pl.ParameterOf(pts[i]));
}
// Assuming we have some points in our list...
if (pts.Count > 0)
{
// We need the center and radius of our circle
Point2d center;
double radius = 0;
// Use our fast approximation algorithm to
// calculate the center and radius of our
// circle to within 1% (calling the function
// with 100 iterations gives 10%, calling it
// with 10K gives 1%)
BadoiuClarksonIteration(
pts2d, 10000, out center, out radius
);
// Get our center point in WCS (on the plane
// of our UCS)
Point3d cen3d = pl.EvaluatePoint(center);
// Create the circle and add it to the drawing
return new Circle(
cen3d, ucs.Zaxis, radius * (1.0 + buffer)
);
}
return null;
}
// Algorithm courtesy (and copyright of) Frank Nielsen
// [url=http://blog.informationgeometry.org/article.php?id=164]http://blog.informationgeometry.org/article.php?id=164[/url]
public void BadoiuClarksonIteration(
List<;Point2d> set, int iter,
out Point2d cen, out double rad
)
{
// Choose any point of the set as the initial
// circumcenter
cen = set[0];
rad = 0;
for (int i = 0; i < iter; i++)
{
int winner = 0;
double distmax = (cen - set[0]).Length;
// Maximum distance point
for (int j = 1; j < set.Count; j++)
{
double dist = (cen - set[j]).Length;
if (dist > distmax)
{
winner = j;
distmax = dist;
}
}
rad = distmax;
// Update
cen =
new Point2d(
cen.X + (1.0 / (i + 1.0)) * (set[winner].X - cen.X),
cen.Y + (1.0 / (i + 1.0)) * (set[winner].Y - cen.Y)
);
}
}
}
}

using Autodesk.AutoCAD.ApplicationServices; 
 
using Autodesk.AutoCAD.DatabaseServices; 
 
using Autodesk.AutoCAD.EditorInput; 
 
using Autodesk.AutoCAD.Runtime; 
 
using Autodesk.AutoCAD.Geometry; 
 
using System.Collections.Generic; 
 
using System.Linq; 
 
using System; 
 
 
 
namespace MinimumEnclosingBoundary 
 
{ 
 
  public class Commands 
 
  { 
 
    [CommandMethod("MER", CommandFlags.UsePickSet)] 
 
    public void MinimumEnclosingRectangle() 
 
    { 
 
      MinimumEnclosingBoundary(false); 
 
    } 
 
 
 
    [CommandMethod("MEC", CommandFlags.UsePickSet)] 
 
    public void MinimumEnclosingCircle() 
 
    { 
 
      MinimumEnclosingBoundary(); 
 
    } 
 
 
 
    public void MinimumEnclosingBoundary( 
 
      bool circularBoundary = true 
 
    ) 
 
    { 
 
      Document doc = 
 
          Application.DocumentManager.MdiActiveDocument; 
 
      Database db = doc.Database; 
 
      Editor ed = doc.Editor; 
 
 
 
      // Ask user to select entities 
 
 
 
      PromptSelectionOptions pso = 
 
        new PromptSelectionOptions(); 
 
      pso.MessageForAdding = "\nSelect objects to enclose: "; 
 
      pso.AllowDuplicates = false; 
 
      pso.AllowSubSelections = true; 
 
      pso.RejectObjectsFromNonCurrentSpace = true; 
 
      pso.RejectObjectsOnLockedLayers = false; 
 
 
 
      PromptSelectionResult psr = ed.GetSelection(pso); 
 
      if (psr.Status != PromptStatus.OK) 
 
        return; 
 
 
 
      bool oneBoundPerEnt = false; 
 
 
 
      if (psr.Value.Count > 1) 
 
      { 
 
        PromptKeywordOptions pko = 
 
          new PromptKeywordOptions( 
 
            "\nMultiple objects selected: create " + 
 
            "individual boundaries around each one?" 
 
          ); 
 
        pko.AllowNone = true; 
 
        pko.Keywords.Add("Yes"); 
 
        pko.Keywords.Add("No"); 
 
        pko.Keywords.Default = "No"; 
 
 
 
        PromptResult pkr = ed.GetKeywords(pko); 
 
        if (pkr.Status != PromptStatus.OK) 
 
          return; 
 
 
 
        oneBoundPerEnt = (pkr.StringResult == "Yes"); 
 
      } 
 
 
 
      // There may be a SysVar defining the buffer 
 
      // to add to our radius 
 
 
 
      double buffer = 0.0; 
 
      try 
 
      { 
 
        object bufvar = 
 
          Application.GetSystemVariable( 
 
            "ENCLOSINGBOUNDARYBUFFER" 
 
          ); 
 
        if (bufvar != null) 
 
        { 
 
          short bufval = (short)bufvar; 
 
          buffer = bufval / 100.0; 
 
        } 
 
      } 
 
      catch 
 
      { 
 
        object bufvar = 
 
          Application.GetSystemVariable("USERI1"); 
 
        if (bufvar != null) 
 
        { 
 
          short bufval = (short)bufvar; 
 
          buffer = bufval / 100.0; 
 
        } 
 
      } 
 
 
 
      // Get the current UCS 
 
 
 
      CoordinateSystem3d ucs = 
 
        ed.CurrentUserCoordinateSystem.CoordinateSystem3d; 
 
 
 
      // Collect points on the component entities 
 
 
 
      Point3dCollection pts = new Point3dCollection(); 
 
 
 
      Transaction tr = 
 
        db.TransactionManager.StartTransaction(); 
 
      using (tr) 
 
      { 
 
        BlockTableRecord btr = 
 
          (BlockTableRecord)tr.GetObject( 
 
            db.CurrentSpaceId, 
 
            OpenMode.ForWrite 
 
          ); 
 
 
 
        for (int i = 0; i < psr.Value.Count; i++) 
 
        { 
 
          Entity ent = 
 
            (Entity)tr.GetObject( 
 
              psr.Value[i].ObjectId, 
 
              OpenMode.ForRead 
 
            ); 
 
 
 
          // Collect the points for each selected entity 
 
 
 
          Point3dCollection entPts = CollectPoints(tr, ent); 
 
          foreach (Point3d pt in entPts) 
 
          { 
 
            /* 
 
             * Create a DBPoint, for testing purposes 
 
             * 
 
            DBPoint dbp = new DBPoint(pt); 
 
            btr.AppendEntity(dbp); 
 
            tr.AddNewlyCreatedDBObject(dbp, true); 
 
             */ 
 
 
 
            pts.Add(pt); 
 
          } 
 
 
 
          // Create a boundary for each entity (if so chosen) or 
 
          // just once after collecting all the points 
 
 
 
          if (oneBoundPerEnt || i == psr.Value.Count - 1) 
 
          { 
 
            try 
 
            { 
 
              Entity bnd = 
 
                (circularBoundary ? 
 
                  CircleFromPoints(pts, ucs, buffer) : 
 
                  RectangleFromPoints(pts, ucs, buffer) 
 
                ); 
 
              btr.AppendEntity(bnd); 
 
              tr.AddNewlyCreatedDBObject(bnd, true); 
 
            } 
 
            catch 
 
            { 
 
              ed.WriteMessage( 
 
                "\nUnable to calculate enclosing boundary." 
 
              ); 
 
            } 
 
 
 
            pts.Clear(); 
 
          } 
 
        } 
 
 
 
        tr.Commit(); 
 
      } 
 
    } 
 
 
 
    private Point3dCollection CollectPoints( 
 
      Transaction tr, Entity ent 
 
    ) 
 
    { 
 
      // The collection of points to populate and return 
 
 
 
      Point3dCollection pts = new Point3dCollection(); 
 
 
 
      // We'll start by checking a block reference for 
 
      // attributes, getting their bounds and adding 
 
      // them to the point list. We'll still explode 
 
      // the BlockReference later, to gather points 
 
      // from other geometry, it's just that approach 
 
      // doesn't work for attributes (we only get the 
 
      // AttributeDefinitions, which don't have bounds) 
 
 
 
      BlockReference br = ent as BlockReference; 
 
      if (br != null) 
 
      { 
 
        foreach (ObjectId arId in br.AttributeCollection) 
 
        { 
 
          DBObject obj = tr.GetObject(arId, OpenMode.ForRead); 
 
          if (obj is AttributeReference) 
 
          { 
 
            AttributeReference ar = (AttributeReference)obj; 
 
            ExtractBounds(ar, pts); 
 
          } 
 
        } 
 
      } 
 
 
 
      // If we have a curve - other than a polyline, which 
 
      // we will want to explode - we'll get points along 
 
      // its length 
 
 
 
      Curve cur = ent as Curve; 
 
      if (cur != null && 
 
          !(cur is Polyline || 
 
            cur is Polyline2d || 
 
            cur is Polyline3d)) 
 
      { 
 
        // Two points are enough for a line, we'll go with 
 
        // a higher number for other curves 
 
 
 
        int segs = (ent is Line ? 2 : 20); 
 
 
 
        double param = cur.EndParam - cur.StartParam; 
 
        for (int i = 0; i < segs; i++) 
 
        { 
 
          try 
 
          { 
 
            Point3d pt = 
 
              cur.GetPointAtParameter( 
 
                cur.StartParam + (i * param / (segs - 1)) 
 
              ); 
 
            pts.Add(pt); 
 
          } 
 
          catch { } 
 
        } 
 
      } 
 
      else if (ent is DBPoint) 
 
      { 
 
        // Points are easy 
 
 
 
        pts.Add(((DBPoint)ent).Position); 
 
      } 
 
      else if (ent is DBText) 
 
      { 
 
        // For DBText we use the same approach as 
 
        // for AttributeReferences 
 
 
 
        ExtractBounds((DBText)ent, pts); 
 
      } 
 
      else if (ent is MText) 
 
      { 
 
        // MText is also easy - you get all four corners 
 
        // returned by a function. That said, the points 
 
        // are of the MText's box, so may well be different 
 
        // from the bounds of the actual contents 
 
 
 
        MText txt = (MText)ent; 
 
        Point3dCollection pts2 = txt.GetBoundingPoints(); 
 
        foreach (Point3d pt in pts2) 
 
        { 
 
          pts.Add(pt); 
 
        } 
 
      } 
 
      else if (ent is Face) 
 
      { 
 
        Face f = (Face)ent; 
 
        try 
 
        { 
 
          for (short i = 0; i < 4; i++) 
 
          { 
 
            pts.Add(f.GetVertexAt(i)); 
 
          } 
 
        } 
 
        catch { } 
 
      } 
 
      else if (ent is Solid) 
 
      { 
 
        Solid sol = (Solid)ent; 
 
        try 
 
        { 
 
          for (short i = 0; i < 4; i++) 
 
          { 
 
            pts.Add(sol.GetPointAt(i)); 
 
          } 
 
        } 
 
        catch { } 
 
      } 
 
      else 
 
      { 
 
        // Here's where we attempt to explode other types 
 
        // of object 
 
 
 
        DBObjectCollection oc = new DBObjectCollection(); 
 
        try 
 
        { 
 
          ent.Explode(oc); 
 
          if (oc.Count > 0) 
 
          { 
 
            foreach (DBObject obj in oc) 
 
            { 
 
              Entity ent2 = obj as Entity; 
 
              if (ent2 != null && ent2.Visible) 
 
              { 
 
                foreach (Point3d pt in CollectPoints(tr, ent2)) 
 
                { 
 
                  pts.Add(pt); 
 
                } 
 
              } 
 
              obj.Dispose(); 
 
            } 
 
          } 
 
        } 
 
        catch { } 
 
      } 
 
      return pts; 
 
    } 
 
 
 
    private void ExtractBounds( 
 
      DBText txt, Point3dCollection pts 
 
    ) 
 
    { 
 
      // We have a special approach for DBText and 
 
      // AttributeReference objects, as we want to get 
 
      // all four corners of the bounding box, even 
 
      // when the text or the containing block reference 
 
      // is rotated 
 
 
 
      if (txt.Bounds.HasValue && txt.Visible) 
 
      { 
 
        // Create a straight version of the text object 
 
        // and copy across all the relevant properties 
 
        // (stopped copying AlignmentPoint, as it would 
 
        // sometimes cause an eNotApplicable error) 
 
 
 
        // We'll create the text at the WCS origin 
 
        // with no rotation, so it's easier to use its 
 
        // extents 
 
 
 
        DBText txt2 = new DBText(); 
 
        txt2.Normal = Vector3d.ZAxis; 
 
        txt2.Position = Point3d.Origin; 
 
 
 
        // Other properties are copied from the original 
 
 
 
        txt2.TextString = txt.TextString; 
 
        txt2.TextStyleId = txt.TextStyleId; 
 
        txt2.LineWeight = txt.LineWeight; 
 
        txt2.Thickness = txt2.Thickness; 
 
        txt2.HorizontalMode = txt.HorizontalMode; 
 
        txt2.VerticalMode = txt.VerticalMode; 
 
        txt2.WidthFactor = txt.WidthFactor; 
 
        txt2.Height = txt.Height; 
 
        txt2.IsMirroredInX = txt2.IsMirroredInX; 
 
        txt2.IsMirroredInY = txt2.IsMirroredInY; 
 
        txt2.Oblique = txt.Oblique; 
 
 
 
        // Get its bounds if it has them defined 
 
        // (which it should, as the original did) 
 
 
 
        if (txt2.Bounds.HasValue) 
 
        { 
 
          Point3d maxPt = txt2.Bounds.Value.MaxPoint; 
 
 
 
          // Place all four corners of the bounding box 
 
          // in an array 
 
 
 
          Point2d[] bounds = 
 
            new Point2d[] { 
 
              Point2d.Origin, 
 
              new Point2d(0.0, maxPt.Y), 
 
              new Point2d(maxPt.X, maxPt.Y), 
 
              new Point2d(maxPt.X, 0.0) 
 
            }; 
 
 
 
          // We're going to get each point's WCS coordinates 
 
          // using the plane the text is on 
 
 
 
          Plane pl = new Plane(txt.Position, txt.Normal); 
 
 
 
          // Rotate each point and add its WCS location to the 
 
          // collection 
 
 
 
          foreach (Point2d pt in bounds) 
 
          { 
 
            pts.Add( 
 
              pl.EvaluatePoint( 
 
                pt.RotateBy(txt.Rotation, Point2d.Origin) 
 
              ) 
 
            ); 
 
          } 
 
        } 
 
      } 
 
    } 
 
 
 
    private Entity RectangleFromPoints( 
 
      Point3dCollection pts, CoordinateSystem3d ucs, double buffer 
 
    ) 
 
    { 
 
      // Get the plane of the UCS 
 
 
 
      Plane pl = new Plane(ucs.Origin, ucs.Zaxis); 
 
 
 
      // We will project these (possibly 3D) points onto 
 
      // the plane of the current UCS, as that's where 
 
      // we will create our circle 
 
 
 
      // Project the points onto it 
 
 
 
      List<;Point2d> pts2d = new List<;Point2d>(pts.Count); 
 
      for (int i = 0; i < pts.Count; i++) 
 
      { 
 
        pts2d.Add(pl.ParameterOf(pts[i])); 
 
      } 
 
 
 
      // Assuming we have some points in our list... 
 
 
 
      if (pts.Count > 0) 
 
      { 
 
        // Set the initial min and max values from the first entry 
 
 
 
        double minX = pts2d[0].X, 
 
               maxX = minX, 
 
               minY = pts2d[0].Y, 
 
               maxY = minY; 
 
 
 
        // Perform a single iteration to extract the min/max X and Y 
 
 
 
        for (int i = 1; i < pts2d.Count; i++) 
 
        { 
 
          Point2d pt = pts2d[i]; 
 
          if (pt.X < minX) minX = pt.X; 
 
          if (pt.X > maxX) maxX = pt.X; 
 
          if (pt.Y < minY) minY = pt.Y; 
 
          if (pt.Y > maxY) maxY = pt.Y; 
 
        } 
 
 
 
        // Our final buffer amount will be the percentage of the 
 
        // smallest of the dimensions 
 
 
 
        double buf = 
 
          Math.Min(maxX - minX, maxY - minY) * buffer; 
 
 
 
        // Apply the buffer to our point ordinates 
 
 
 
        minX -= buf; 
 
        minY -= buf; 
 
        maxX += buf; 
 
        maxY += buf; 
 
 
 
        // Create the boundary points 
 
 
 
        Point2d pt0 = new Point2d(minX, minY), 
 
                pt1 = new Point2d(minX, maxY), 
 
                pt2 = new Point2d(maxX, maxY), 
 
                pt3 = new Point2d(maxX, minY); 
 
 
 
        // Finally we create the polyline 
 
 
 
        var p = new Polyline(4); 
 
        p.Normal = pl.Normal; 
 
        p.AddVertexAt(0, pt0, 0, 0, 0); 
 
        p.AddVertexAt(1, pt1, 0, 0, 0); 
 
        p.AddVertexAt(2, pt2, 0, 0, 0); 
 
        p.AddVertexAt(3, pt3, 0, 0, 0); 
 
        p.Closed = true; 
 
 
 
        return p; 
 
      } 
 
      return null; 
 
    } 
 
 
 
    private Entity CircleFromPoints( 
 
      Point3dCollection pts, CoordinateSystem3d ucs, double buffer 
 
    ) 
 
    { 
 
      // Get the plane of the UCS 
 
 
 
      Plane pl = new Plane(ucs.Origin, ucs.Zaxis); 
 
 
 
      // We will project these (possibly 3D) points onto 
 
      // the plane of the current UCS, as that's where 
 
      // we will create our circle 
 
 
 
      // Project the points onto it 
 
 
 
      List<;Point2d> pts2d = new List<;Point2d>(pts.Count); 
 
      for (int i = 0; i < pts.Count; i++) 
 
      { 
 
        pts2d.Add(pl.ParameterOf(pts[i])); 
 
      } 
 
 
 
      // Assuming we have some points in our list... 
 
 
 
      if (pts.Count > 0) 
 
      { 
 
        // We need the center and radius of our circle 
 
 
 
        Point2d center; 
 
        double radius = 0; 
 
 
 
        // Use our fast approximation algorithm to 
 
        // calculate the center and radius of our 
 
        // circle to within 1% (calling the function 
 
        // with 100 iterations gives 10%, calling it 
 
        // with 10K gives 1%) 
 
 
 
        BadoiuClarksonIteration( 
 
          pts2d, 10000, out center, out radius 
 
        ); 
 
 
 
        // Get our center point in WCS (on the plane 
 
        // of our UCS) 
 
 
 
        Point3d cen3d = pl.EvaluatePoint(center); 
 
 
 
        // Create the circle and add it to the drawing 
 
 
 
        return new Circle( 
 
          cen3d, ucs.Zaxis, radius * (1.0 + buffer) 
 
        ); 
 
      } 
 
      return null; 
 
    } 
 
 
 
    // Algorithm courtesy (and copyright of) Frank Nielsen 
 
    // [url=http://blog.informationgeometry.org/article.php?id=164]http://blog.informationgeometry.org/article.php?id=164[/url] 
 
 
 
    public void BadoiuClarksonIteration( 
 
      List<;Point2d> set, int iter, 
 
      out Point2d cen, out double rad 
 
    ) 
 
    { 
 
      // Choose any point of the set as the initial 
 
      // circumcenter 
 
 
 
      cen = set[0]; 
 
      rad = 0; 
 
 
 
      for (int i = 0; i < iter; i++) 
 
      { 
 
        int winner = 0; 
 
        double distmax = (cen - set[0]).Length; 
 
 
 
        // Maximum distance point 
 
 
 
        for (int j = 1; j < set.Count; j++) 
 
        { 
 
          double dist = (cen - set[j]).Length; 
 
          if (dist > distmax) 
 
          { 
 
            winner = j; 
 
            distmax = dist; 
 
          } 
 
        } 
 
        rad = distmax; 
 
 
 
        // Update 
 
 
 
        cen = 
 
          new Point2d( 
 
            cen.X + (1.0 / (i + 1.0)) * (set[winner].X - cen.X), 
 
            cen.Y + (1.0 / (i + 1.0)) * (set[winner].Y - cen.Y) 
 
          ); 
 
      } 
 
    } 
 
  } 
 
}

Here’s the MER command in action, using a 15% boundary and choosing to create individual boundaries for each object:

Rectangular boundaries around geometry

csharp · 发表于 2014-5-15 10:27:27

Rectang 对 Spline 有误差

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[分享] Creating the smallest possible rectangle around 2D AutoCAD geometry using .NET

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