;  ZOOMBACK.LSP
;
;                         QUICK COMMAND version 2.0
;                   ZOOMBACK.LSP is a module of QUICK COMMAND
;                        Copyright 1989, 1990 Dan Jincks
;
;
;              This is SHAREWARE, it is NOT Public Domain software.
;
;              This code or any part of this code may not be reproduced
;              in any publication without prior written permission.
;
;              Printed copy of this code or any part of this code may not
;              be distributed without prior written permission.
;
;              Printed copy may only be made for reference purposes by
;              the end user.
;
;
;                               Dan Jincks
;                             Box 155A HCR 77
;                           Annapolis, MO 63620
;
;
;
;   You are granted a limited license to use ZOOMBACK.LSP for a 30 day trial
;   period.  If you wish to continue using any or all of QUICK COMMAND after
;   the trial period, you must become a registered user.  As a registered
;   user, you may use QUICK COMMAND on 1 workstation or terminal.
;   Additional registrations must be bought for each additional workstation or
;   terminal.  To become a registered user, fill out the order form that can
;   be printed out from ORDERQC.DOC .
;
;
;   You may send copies of QUICK COMMAND to friends and associates if you abide
;   by the following rules:
;
;   1. It may only be distributed in the original unmodified form.
;   2. All original files must be included.
;   3. No addition files may be added.
;   4. If other files will be on the same disk, QUICK COMMAND files must be in
;      a library format such as ".ARC" called "QUICKCMD", or else be put alone
;      in a subdirectory called "QUICKCMD".
;   5. You may not sell QUICK COMMAND or any part of it.
;   6. You are not allowed to charge more then $5 to cover the cost of copying
;      and distribution.
;   7. You may not distribute any hard copy of the contents of QUICK COMMAND.
;
;
;   These AutoLISP commands and functions are designed to save you time, and
;   saving time means saving money.  The registration fee is very modest
;   compared to the savings, and much less expensive then typical third party
;   AutoCAD software. Be sure to registar if you continue to use them.
;
;
;                                                               DAN
;
;
;
;
;        AutoCAD and AutoLISP are registered trade marks of Autodesk Inc.
;
;        ***************************************************************
;
;   Begin ZOOMBACK.LSP
;
(defun C:ZB (/ SCA SCB SCC SCD SCE SCF SCG SCH)
   (setq SCA (getvar "vsmax") SCB (getvar "vsmin"))
   (if (and (> (car SCA)(car SCB))(> (cadr SCA)(cadr SCB)))(progn
      (setq SCG (* (- (car SCA)(car SCB)) 0.001)
            SCH (* (- (cadr SCA)(cadr SCB)) 0.001)
            SCC (- (car SCA) SCG)
            SCD (- (cadr SCA) SCH)
            SCE (+ (car SCB) SCG)
            SCF (+ (cadr SCB) SCH))
   ))
   (if (and (< (car SCA)(car SCB))(> (cadr SCA)(cadr SCB)))(progn
      (setq SCG (* (- (car SCB)(car SCA)) 0.001)
            SCH (* (- (cadr SCA)(cadr SCB)) 0.001)
            SCC (+ (car SCA) SCG)
            SCD (- (cadr SCA) SCH)
            SCE (- (car SCB) SCG)
            SCF (+ (cadr SCB) SCH))
   ))
   (if (and (> (car SCA)(car SCB))(< (cadr SCA)(cadr SCB)))(progn
      (setq SCG (* (- (car SCA)(car SCB)) 0.001)
            SCH (* (- (cadr SCB)(cadr SCA)) 0.001)
            SCC (- (car SCA) SCG)
            SCD (+ (cadr SCA) SCH)
            SCE (+ (car SCB) SCG)
            SCF (- (cadr SCB) SCH))
   ))
   (if (and (< (car SCA)(car SCB))(< (cadr SCA)(cadr SCB)))(progn
      (setq SCG (* (- (car SCB)(car SCA)) 0.001)
            SCH (* (- (cadr SCB)(cadr SCA)) 0.001)
            SCC (+ (car SCA) SCG)
            SCD (+ (cadr SCA) SCH)
            SCE (- (car SCB) SCG)
            SCF (- (cadr SCB) SCH))
   ))
   (if (and SCC SCD SCE SCF)
      (command "ZOOM" "W" (list SCC SCD)(list SCE SCF))
      (prompt " Equal X or Y at corners of screen. Can't zoom.")
   )(princ)
)
;
;   End ZOOMBACK.LSP