(defun c:SNAPBLOCKTOGRID (/ ss i ent ed inspt snap tol restx resty newpt)
  (setq tol 1e-6)
  (setq snap (getvar "SNAPUNIT"))
  
  (if (= 0 (getvar "SNAPMODE")) (setvar "SNAPMODE" 1))
  (setq ss (ssget "_X" '((0 . "INSERT"))))
  
  (if ss
    (progn
      (princ (strcat "\nZpracovávám " (itoa (sslength ss)) " bloků..."))
      (setq i 0)
      (while (< i (sslength ss))
        (setq ent   (ssname ss i)
              ed    (entget ent)
              inspt (cdr (assoc 10 ed)))
        ;; Zbytek po dělení rozestupem ("modulo"), korekce čisté násobnosti
        (setq restx (abs (rem (car inspt) (car snap))))
        (setq resty (abs (rem (cadr inspt) (cadr snap))))
        ;; Pokud alespoň X nebo Y není "v rastru", blok zarovnáme
        (if (or (> restx tol) (> resty tol))
          (progn
            (setq newpt
              (list
                (* (car snap) (fix (+ (/ (car inspt) (car snap)) 0.5)))
                (* (cadr snap) (fix (+ (/ (cadr inspt) (cadr snap)) 0.5)))
                (caddr inspt)))
            (entmod (subst (cons 10 newpt) (assoc 10 ed) ed))
            (princ (strcat "\n• Posun blok ID " (cdr (assoc 5 ed))))
          )
        )
        (setq i (1+ i))
      )
      (command "REGEN")
      (princ "\nHotovo.")
    )
    (princ "\nŽádné bloky k posunu.")
  )
  (princ)
)