public static void Break()
{
ObjectId LayerOfBreakLine;
// Get the current document and database
Document acDoc = Application.DocumentManager.MdiActiveDocument;
Database acCurDb = acDoc.Database;
LineSegment3d seg1 = new LineSegment3d();
LineSegment3d seg2 = new LineSegment3d();
// Start a transaction
using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
{
// Pick the line/polyline that will be broke
PromptEntityResult acSSPrompt1 = acDoc.Editor.GetEntity("Pick the line to break");
// If the prompt status is OK, objects were selected
if (acSSPrompt1.Status == PromptStatus.OK)
{
ObjectId obj1 = acSSPrompt1.ObjectId;
Entity ent1 = acTrans.GetObject(obj1, OpenMode.ForWrite) as Entity;
LayerOfBreakLine = ent1.LayerId;
switch (obj1.ObjectClass.DxfName)
{
case "LINE":
Line ln1 = new Line();
ln1 = (Line)ent1;
seg1 = new LineSegment3d(new Point3d(ln1.StartPoint.X, ln1.StartPoint.Y, ln1.StartPoint.Z), new Point3d(ln1.EndPoint.X, ln1.EndPoint.Y, ln1.EndPoint.Z));
break;
case "LWPOLYLINE":
Polyline pln1 = new Polyline();
pln1 = (Polyline)ent1;
//loops through each segment of the polyline and finds which one our user selected point resides on
for (int x = 0; x < pln1.NumberOfVertices; x++)
{
//converts a 3d point to 2d point that would be on the 2d polyline
Point2d temppt = pln1.GetClosestPointTo(acSSPrompt1.PickedPoint, false).Add(pln1.StartPoint.GetAsVector()).Convert2d(pln1.GetPlane());
//then checks if that 2d point resides on the current segment being looked at
if (pln1.OnSegmentAt(x, temppt, 0.00))
{
seg1 = pln1.GetLineSegmentAt(x);
break;
}
}
break;
}
// Pick the line/polyline that intersects with the line to be broke
PromptEntityResult acSSPrompt2 = acDoc.Editor.GetEntity("Pick the intersecting line");
// If the prompt status is OK, objects were selected
if (acSSPrompt2.Status == PromptStatus.OK)
{
ObjectId obj2 = acSSPrompt2.ObjectId;
Entity ent2 = acTrans.GetObject(obj2, OpenMode.ForWrite) as Entity;
switch (obj2.ObjectClass.DxfName)
{
case "LINE":
Line ln2 = new Line();
ln2 = (Line)ent2;
seg2 = new LineSegment3d(new Point3d(ln2.StartPoint.X, ln2.StartPoint.Y, ln2.StartPoint.Z), new Point3d(ln2.EndPoint.X, ln2.EndPoint.Y, ln2.EndPoint.Z));
break;
case "LWPOLYLINE":
Polyline pln2 = new Polyline();
pln2 = (Polyline)ent2;
for (int x = 0; x < pln2.NumberOfVertices; x++)
{
Point2d temppt = pln2.GetClosestPointTo(acSSPrompt2.PickedPoint, false).Add(pln2.StartPoint.GetAsVector()).Convert2d(pln2.GetPlane());
if (pln2.OnSegmentAt(x, temppt, 0.00))
{
seg2 = pln2.GetLineSegmentAt(x);
break;
}
}
break;
}
//checks if the line segments actually intersect
//also checks if the line segment are the same
//both cases would cause AutoCAD to crash if the code was allowed to run
if (seg1.IntersectWith(seg2) != null || (seg1.Equals(seg2)))
{
//gets the start and endpoint of the segment selected
Point2d pt1 = new Point2d(seg1.StartPoint.X, seg1.StartPoint.Y);
Point2d pt2 = new Point2d(seg1.EndPoint.X, seg1.EndPoint.Y);
//with those two points we can calculate the angle of the first segment
double angle1 = pt1.GetVectorTo(pt2).Angle;
double angle2 = pt2.GetVectorTo(pt1).Angle;
//get the point where the two segments intersect
Point3d[] intersectpoint = seg1.IntersectWith(seg2);
Point3d center = intersectpoint[0];
//using the centerpoint and the angle, calculate the vector of where to break the line segment
Point3d point1 = new Point3d(center.X + .125 * Math.Cos(angle1), center.Y + .125 * Math.Sin(angle1), 0);
Point3d point2 = new Point3d(center.X + .125 * Math.Cos(angle2), center.Y + .125 * Math.Sin(angle2), 0);
BlockTable acBlkTbl;
acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForWrite) as BlockTable;
BlockTableRecord acBlkTbleRec;
acBlkTbleRec = acTrans.GetObject(acCurDb.CurrentSpaceId, OpenMode.ForWrite) as BlockTableRecord;
//ready to replace the original line/polyline with two new entities
switch (obj1.ObjectClass.DxfName)
{
case "LINE":
ent1.Erase(true);
Line newline1 = new Line(new Point3d(seg1.StartPoint.X, seg1.StartPoint.Y, seg1.StartPoint.Z), point2);
Line newline2 = new Line(point1, new Point3d(seg1.EndPoint.X, seg1.EndPoint.Y, seg1.EndPoint.Z));
newline1.LayerId = LayerOfBreakLine;
newline2.LayerId = LayerOfBreakLine;
acBlkTbleRec.AppendEntity(newline1);
acBlkTbleRec.AppendEntity(newline2);
acTrans.AddNewlyCreatedDBObject(newline1, true);
acTrans.AddNewlyCreatedDBObject(newline2, true);
break;
case "LWPOLYLINE":
Polyline oldpl = new Polyline();
oldpl = (Polyline)ent1;
//create the first polyline on one side of the break
Polyline newpl1 = new Polyline();
newpl1.LayerId = LayerOfBreakLine;
for (int x = 0; seg1.EndPoint != oldpl.GetPoint3dAt(x); x++)
{
newpl1.AddVertexAt(x, oldpl.GetPoint2dAt(x), 0, 0, 0);
}
//add end point
newpl1.AddVertexAt(newpl1.NumberOfVertices, new Point2d(point2.X, point2.Y), 0, 0, 0);
//create the second polyline at the other side of the break
Polyline newpl2 = new Polyline();
newpl2.LayerId = LayerOfBreakLine;
int i = 0; //for tracking the index of our new polyline
//start at the end of the old polyline and work our way backwards to the break point
for (int x = oldpl.NumberOfVertices - 1; seg1.StartPoint != oldpl.GetPoint3dAt(x); x--)
{
newpl2.AddVertexAt(i, oldpl.GetPoint2dAt(x), 0, 0, 0);
i++;
}
//add end point
newpl2.AddVertexAt(i, new Point2d(point1.X, point1.Y), 0, 0, 0);
//erases the old polyline and adds the new two polylines to the database
ent1.Erase(true);
acBlkTbleRec.AppendEntity(newpl1);
acBlkTbleRec.AppendEntity(newpl2);
acTrans.AddNewlyCreatedDBObject(newpl1, true);
acTrans.AddNewlyCreatedDBObject(newpl2, true);
break;
}
//commit everything
acTrans.Commit();
}
}
}
}
}
