;;; ---------------------------------------------------------------------
;;;  VTXBLK-bgol.lsp
;;;  Command:  IBVX
;;;
;;;  PURPOSE
;;;  Inserts a copy of a chosen (non-attribute) block at every vertex of
;;;  one or more selected polylines. Useful for marking boundary stones,
;;;  survey markers, or direction-change points along a polyline.
;;;
;;;  USAGE
;;;    1. Ensure the target block is already defined in the drawing.
;;;    2. Load this file (APPLOAD or drag-drop onto the drawing window).
;;;    3. Type   IBVX   at the command line and press Enter.
;;;    4. Select one or more polylines.
;;;    5. Type the name of the block to insert.
;;;    6. A copy of that block is inserted at every vertex of every
;;;       selected polyline, on layer "BGOL-IBVX".
;;;
;;;  NOTES
;;;    - Per the source utility this is based on, blocks that contain
;;;      attribute definitions are NOT supported; this routine checks
;;;      the block definition and refuses to proceed if it contains any
;;;      ATTDEF sub-entities.
;;;    - Block scale and rotation default to 1/1/0; edit
;;;      *bgol-ibvx-scale* and *bgol-ibvx-rot* below to change defaults.
;;;    - This is an original, independently written implementation.
;;;      It is INSPIRED by the general idea of vertex-based block
;;;      insertion common in survey/boundary marking workflows, but the
;;;      code, command name and file name here are new and are NOT
;;;      copied from, nor identical to, any specific third-party
;;;      product.
;;;
;;;  ---------------------------------------------------------------------
;;;  Developed and shared for the CAD community by:  BGol Community
;;;  Community website:                              https://bgol.in/
;;;  License:  Open-source & free to use, modify, and share for all.
;;;            Provided "as is", without warranty of any kind.
;;;  ---------------------------------------------------------------------

(vl-load-com)

(setq *bgol-ibvx-scale* 1.0)
(setq *bgol-ibvx-rot* 0.0)

(defun BGOL:IBVX-EnsureLayer (lname / )
  (if (not (tblsearch "LAYER" lname))
    (entmake (list '(0 . "LAYER")
                   '(100 . "AcDbSymbolTableRecord")
                   '(100 . "AcDbLayerTableRecord")
                   (cons 2 lname)
                   '(70 . 0)
                   '(62 . 5)          ; blue
                   '(6 . "Continuous")))
  )
)

(defun BGOL:IBVX-HasAttdefs (blkname / bent bdata found)
  (setq found nil)
  (setq bent (tblobjname "BLOCK" blkname))
  (if bent
    (progn
      (setq bent (entnext bent))
      (while (and bent (not found))
        (setq bdata (entget bent))
        (if (= (cdr (assoc 0 bdata)) "ATTDEF")
          (setq found T)
        )
        (setq bent (entnext bent))
      )
    )
  )
  found
)

(defun BGOL:IBVX-InsertBlock (blkname pt lname scl rot / )
  (entmake (list '(0 . "INSERT")
                 '(100 . "AcDbEntity")
                 (cons 8 lname)
                 '(100 . "AcDbBlockReference")
                 (cons 2 blkname)
                 (cons 10 pt)
                 (cons 41 scl)
                 (cons 42 scl)
                 (cons 43 scl)
                 (cons 50 rot)))
)

(defun C:IBVX ( / ss lname blkname n i ent obj coords m j pt cnt)
  (setq lname "BGOL-IBVX")
  (BGOL:IBVX-EnsureLayer lname)
  (setq ss (ssget '((0 . "LWPOLYLINE"))))
  (if ss
    (progn
      (setq blkname (getstring T "\nBlock name to insert at each vertex: "))
      (cond
        ((not (tblsearch "BLOCK" blkname))
         (princ (strcat "\nBlock \"" blkname "\" is not defined in this drawing. Nothing inserted."))
        )
        ((BGOL:IBVX-HasAttdefs blkname)
         (princ (strcat "\nBlock \"" blkname "\" contains attribute definitions. "
                         "This routine only supports non-attribute blocks. Nothing inserted."))
        )
        (t
         (setq n (sslength ss))
         (setq i 0)
         (setq cnt 0)
         (while (< i n)
           (setq ent (ssname ss i))
           (setq obj (vlax-ename->vla-object ent))
           (setq coords (vlax-invoke obj 'Coordinates))
           (setq m (/ (length coords) 2))
           (setq j 0)
           (while (< j m)
             (setq pt (list (nth (* 2 j) coords) (nth (1+ (* 2 j)) coords)))
             (BGOL:IBVX-InsertBlock blkname pt lname *bgol-ibvx-scale* *bgol-ibvx-rot*)
             (setq cnt (1+ cnt))
             (setq j (1+ j))
           )
           (setq i (1+ i))
         )
         (princ (strcat "\n" (itoa cnt) " block(s) inserted at polyline vertices (BGOL-IBVX)."))
        )
      )
    )
    (princ "\nNo polylines selected.")
  )
  (princ)
)

(princ "\nVTXBLK-bgol.lsp loaded. Type IBVX to insert a block at every vertex of selected polylines.")
(princ "\n  -- Free & open-source, courtesy of BGol Community (https://bgol.in/) --")
(princ)