Offset Objects

theswamp

• 1. public static class AlgerbraicArea

  2. {

  3. public static double GetArea(Point2d pt1, Point2d pt2, Point2d pt3)

  4. {

  5. return (((pt2.X - pt1.X) * (pt3.Y - pt1.Y)) -

  6. ((pt3.X - pt1.X) * (pt2.Y - pt1.Y))) / 2.0;

  7. }

  9. public static double GetArea(this CircularArc2d arc)

  10. {

  11. double rad = arc.Radius;

  12. double ang = arc.IsClockWise ?

  13. arc.StartAngle - arc.EndAngle :

  14. arc.EndAngle - arc.StartAngle;

  15. return rad * rad * (ang - Math.Sin(ang)) / 2.0;

  16. }

  18. public static double GetArea(this Polyline pline)

  19. {

  20. CircularArc2d arc = new CircularArc2d();

  21. double area = 0.0;

  22. int last = pline.NumberOfVertices - 1;

  23. Point2d p0 = pline.GetPoint2dAt(0);

  25. if (pline.GetBulgeAt(0) != 0.0)

  26. {

  27. area += pline.GetArcSegment2dAt(0).GetArea();

  28. }

  29. for (int i = 1; i < last; i++)

  30. {

  31. area += GetArea(p0, pline.GetPoint2dAt(i), pline.GetPoint2dAt(i + 1));

  32. if (pline.GetBulgeAt(i) != 0.0)

  33. {

  34. area += pline.GetArcSegment2dAt(i).GetArea(); ;

  35. }

  36. }

  37. if ((pline.GetBulgeAt(last) != 0.0) && pline.Closed)

  38. {

  39. area += pline.GetArcSegment2dAt(last).GetArea();

  40. }

  41. return area;

  42. }

  43. }

  44. [CommandMethod("OFIN")]

  45. public void OffsetInside()

  46. {

  47. OffsetPolyline(true);

  48. }

  50. [CommandMethod("OFOUT")]

  51. public void OffsetOutside()

  52. {

  53. OffsetPolyline(false);

  54. }

  56. private void OffsetPolyline(bool inside)

  57. {

  58. Document doc = Application.DocumentManager.MdiActiveDocument;

  59. Database db = doc.Database;

  60. Editor ed = doc.Editor;

  62. PromptDistanceOptions pdo =

  63. new PromptDistanceOptions("\nSpecify the offset distance: ");

  64. pdo.AllowNegative = false;

  65. pdo.AllowZero = false;

  66. PromptDoubleResult pdr = ed.GetDistance(pdo);

  67. if (pdr.Status != PromptStatus.OK)

  68. return;

  69. double offsetDist = inside ? pdr.Value : -pdr.Value;

  71. PromptEntityOptions peo = new PromptEntityOptions("\nSelect a polyline: ");

  72. peo.SetRejectMessage("Selected object is not a polyline.");

  73. peo.AddAllowedClass(typeof(Polyline), true);

  75. using (Transaction tr = db.TransactionManager.StartTransaction())

  76. {

  77. BlockTableRecord btr =

  78. (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite);

  79. while (true)

  80. {

  81. PromptEntityResult per = ed.GetEntity(peo);

  82. if (per.Status != PromptStatus.OK)

  83. break;

  84. Polyline pline = (Polyline)tr.GetObject(per.ObjectId, OpenMode.ForRead);

  85. DBObjectCollection offsets =

  86. pline.GetOffsetCurves(pline.GetArea() < 0.0 ? offsetDist : -offsetDist);

  87. foreach (DBObject obj in offsets)

  88. {

  89. Entity ent = (Entity)obj;

  90. btr.AppendEntity(ent);

  91. tr.AddNewlyCreatedDBObject(ent, true);

  92. db.TransactionManager.QueueForGraphicsFlush();

  93. }

  94. }

  95. tr.Commit();

  96. }

  97. }