                                     
     +==========================================================+
           READC3.TXT - AutoCAD R13c3_c2 Maintenance Release
     +==========================================================+
                                   
                             29 June 1995


=====================================================================-
CONTENTS
========-

  - Purpose
  - Background
  - General Questions & Answers
  - Major Enhancements in R13c3
  - Installation Procedure
  - Problems Fixed by R13c3
  - Platform Independent Information
  - Windows-Specific Information
  - Manual Corrections and Additions



=====================================================================-
PURPOSE
=======-

Autodesk is committed to delivering products of the highest quality.
With any major software release, some problems are found after the
product ships. Autodesk is committed to proactively addressing quality
concerns, and therefore has developed a software upgrade procedure to
distribute bug fixes as quickly and easily as possible. The purpose of
this document is to explain the upgrade procedure in general, as well
as specific information about AutoCAD Release 13c3_c2.


=====================================================================-
BACKGROUND
==========-

Problems are reported through the dealer network to Autodesk Product
Support or by customers by filling out a bug report form provided in
the back of the Installation Guide and mailing it to Autodesk. Once a
problem is verified as a bug, it is entered into Autodesk's bug
tracking system. Once bugs are fixed, software patch programs are
created to correct the problems.

In the past, bug fixes required customers to reinstall and reconfigure
the entire product. Now, using software patch technology, dealers and
customers are able to use a quick, straight-forward procedure to
correct the problems without reinstalling AutoCAD. In many cases,
patches will not affect any customization or configuration options.


=====================================================================-
GENERAL QUESTIONS & ANSWERS
===========================-

How do software patches work?
-----------------------------
Release 13 was specifically designed so it can be easily upgraded in
the field. The software patch is actually a program that is able to
modify existing files. When a patch is installed, it replaces the
current file(s) with the new file(s).


What are the benefits of using patches?
---------------------------------------
Most importantly, it allows us to get bug fixes out to our customers
faster. Because it is a subset of the program, patches can be freely
copied and distributed among AutoCAD dealers and customers. Software
patches can also be effectively distributed electronically. Finally,
patches do not require new serial numbers or authorization codes, and
in many cases, will not affect customization.


How does Autodesk distribute patches?
-------------------------------------
Software patches are posted worldwide to the general forums of
CompuServe, Global Village, and Internet and can be freely downloaded
by dealers and customers. A text file for each patch is posted so
customers can determine whether they need a particular patch. Once a
patch is downloaded, it can be copied and distributed among AutoCAD
customers. If you don't have electronic access to these files, please
contact your Authorized Autodesk Reseller or your local Autodesk
office for a copy of the latest patch.

IMPORTANT NOTE:  Please be aware that a software patch supplements the
original disk set and does not replace existing media. Customers
should store the software patch media with the original media disk
set.


What customers do these patches affect?
---------------------------------------
Software patches are distributed as either an update patch or a
maintenance patch.

Update patches typically contain a limited number of bug fixes or
fixes to bugs that may not affect large groups of customers. These
patches are made on an as-needed basis. Autodesk recommends that
dealers distribute update patches to customers who have reported the
specific problems that the patches fix. Since we do not want to
inconvenience our customers with multiple patches in a relatively
short period of time, we do not recommend that these fixes be
distributed to all customers. However, some customers will always want
the latest version and are willing to take the time to install it.
These customers should either download the patches electronically or
work out an arrangement with their dealer.

Maintenance patches are significantly broader in scope than update
patches. They contain all bug fixes that have previously been made
available through update patches, as well as additional bug fixes, and
in some cases may include new functionality. Maintenance patches are
synchronized with maintenance releases which are used to manufacture
new units. We recommend that dealers proactively distribute
maintenance patches to all of their existing Release 13 customers. It
is our goal to have all customers synchronized with the latest
maintenance release.

Autodesk also recommends that dealers include the latest patch with
any new sales or in any new installations.


How are update patches and maintenance patches differentiated?
--------------------------------------------------------------
Update patches are designated with a letter and maintenance patches
are designated by a number. For example, R13c1 indicates a maintenance
patch. R13c1a or R13c1b would indicate the sequence of update patches
released after the R13c1 maintenance patch.


How can I tell whether a patch has been installed already?
----------------------------------------------------------
The patch automatically changes the version number located in the Help
About box.


If more than one patch exists, do I need to install all of them?
----------------------------------------------------------------
Depending on your current AutoCAD version number you may need to
install more than one patch to upgrade to the current version. Update
patches will typically only upgrade AutoCAD from a previous update
release or from the last maintenance release. Maintenance patches are
available that can upgrade AutoCAD from the previous maintenance
release or from any prior release. Your Authorized AutoCAD Reseller
can assist you in finding the appropriate patches for your
installation.

The patch name indicates both the AutoCAD version that results from
applying the patch and the minimum required current version. For
example, the R13c3_c2 patch must be applied to an installed R13c2
version of AutoCAD, and the R13c3_c0 can be applied to any version of
AutoCAD Release 13.


How reliable is this patch technology?
--------------------------------------
When creating a patch, the patch builder program creates a checksum of
the original file. The patch program uses this checksum to ensure that
it is modifying the correct file. Other major software vendors are
also using this technology with great success, and Autodesk used it in
a number of cases with Release 12.


What technology does Autodesk use to create these patches?
----------------------------------------------------------
We use RTPatch from PocketSoft and PKZIP from PKWARE.


How easy is a patch to install?
-------------------------------
An easy-to-use batch file automates the whole procedure. You simply
type the batch command and follow the instructions on your screen. The
process for installing either DOS, Windows or Windows NT typically
takes approximately fifteen minutes.


Should I exchange any unopened or uninstalled product?
------------------------------------------------------
It is not necessary to exchange existing product -- simply run the
appropriate patch(es) after the standard installation.


=====================================================================-
MAJOR ENHANCEMENTS IN R13C3
===========================-

The following items are major enhancements for R13c3. They are
described in greater detail in later sections of this file.

+   Performance improvements:
    - AutoCAD WHIP display list driver for Windows and Windows NT
    - Incremental save feature, optional BAK file
    - Undo file on disk (memory usage reduction)
    - Other:  menu load, array, editing, selection, mtext, AutoCAD
    load, open, electronic documentation, text scrolling, and memory
    usage
+   Patch process improvements
+   Bug fixes


=====================================================================-
INSTALLATION PROCEDURE
======================-

The R13c3_c2 patch must be installed after proper installation of
releases R13c2, R13c2a, or R13c2b. The R13c3_c2 patch works with all
English-language versions of AutoCAD. No new authorization codes are
required, and the serial number and personalization information of the
installed copy of AutoCAD is retained.

1.  The R13c3_c2 patch modifies or installs the following files. No
    customized files are affected and backing up is not required.

      DOS                     Windows/NT
      ------------------      ------------------------
      acad.exe                acad.exe
      acad.xmx                acad.xmx
      acadl.exp               acadres.dll
      acis.dll                acadbtn.dll
      acinst.dll              acis.dll
      acadapp.exp             acinst.dll
      drv/plppost.exp         acadapp.exe
      support/dxfix.exe       dsai.dll
      support/dxfix.doc       drv/plppost.dll
      support/dxfix13.txt     drv/plsys.dll
      support/dxfix13.dxt     support/dxfix.exe
      fonts/txt.shx           support/dxfix.doc
      readme.ren              support/dxfix13.txt
      readme.txt              support/dxfix13.dxt
      cfigphar.exe            fonts/txt.shx
      ads/adslib.h            readme.wri
      render.arx              readme.ren
      render.xmx              readme.txt
      support/ddattdef.lsp    ads/adslib.h
      support/ddinsert.lsp    render.arx
      support/ddmodify.lsp    render.xmx
      support/xplode.lsp      support/ddattdef.lsp
      ase.arx                 support/ddinsert.lsp
      asidb3.exp              support/ddmodify.lsp
      asidb4.exp              support/xplode.lsp
      asifxp.exp              support/rtpanzm.mnu
      asiora.exp              support/1_rtpan.bmp
      asiora16.exe            support/1_rtzoom.bmp
      asipdx.exp              support/3_rtzoom.bmp
      asipdx16.exe            ase.arx
                              asidb3.exe
                              asifxp.exe
                              asiodbc.exe
                              asiodbcs.exe
                              asipdx.exe
                              asipdx16.exe
                              asissrv.exe

2.  When running the installation program you must specify which
    AutoCAD version you are updating (locked or unlocked). The update
    for the locked version should be applied to the network version
    of AutoCAD.
3.  The following installation instructions assume that you have
    installed AutoCAD for Windows or Windows NT in the \acadr13\win
    directory and AutoCAD for DOS in the \acadr13\dos directory on
    drive C. If you have installed AutoCAD on a drive other than C or
    in directories with names other than the defaults, substitute
    your drive/directory names in the commands listed below for the
    default directory names. These instructions also assume that your
    floppy drive is drive A. If you are installing from a drive other
    than A, replace that shown with drive letter appropriate to your
    system.


AutoCAD for Windows or Windows NT
---------------------------------
Important: The R13c3_c2 installation program should not be run from a
DOS shell under Windows.

3a. Navigate to the directory that contains the Windows ACAD.EXE file.
    For example, enter the following at a DOS prompt:

      c:
      cd \acadr13\win

3b. If installing the patch from a floppy drive and your "common"
    directory is acadr13\com directory on drive C, place
    the disk in drive A, and enter the following to install the
    unlocked version:

      a:\wininst a: c:\acadr13\com /U

    or the following to install the locked version:

      a:\wininst a: c:\acadr13\com /L

    or,

3b. If installing the patch from a directory on the hard drive such
    as c:\update and your "common" directory is in the \acadr13\com
    directory on drive C, enter the following to install the unlocked
    version:

      c:\update\wininst c:\update c:\acadr13\com /U

    or the following to install the locked version:

      c:\update\wininst c:\update c:\acadr13\com /L

    and follow the instructions on the screen.

    If you plan to use the WHIP display driver you need to install
    WinG. Refer to the WinG Installation instructions later in this
    document.

    It is recommended that you upgrade to Win32s v.1.25 (however, it
    is not required). You can get the new version from your dealer or
    from the Microsoft forum on CompuServe.


AutoCAD for DOS
---------------
3a. Navigate to the directory that contains the DOS ACAD.EXE file.
    For example, enter the following at a DOS prompt:
     
      c:
      cd \acadr13\dos

3b. If installing the patch from a floppy drive and your "common"
    directory is acadr13\com directory on drive C, place
    the disk in drive A, and enter the following to install the
    unlocked version:

      a:\dosinst a: c:\acadr13\com /U

    or the following to install the locked version:

      a:\dosinst a: c:\acadr13\com /L

    or,

3b. If installing the patch from a directory on the hard drive such
    as c:\update and your "common" directory is in the \acadr13\com
    directory on drive C, enter the following to install the unlocked
    version:

      c:\update\wininst c:\update c:\acadr13\com /U

    or the following to install the locked version:

      c:\update\wininst c:\update c:\acadr13\com /L

    and follow the instructions on the screen.

4.  The patch is applied. This file, READC3.TXT, is also installed
    into the AutoCAD directory by the patch program.

5.  Launch AutoCAD as you normally would.



=====================================================================-
PROBLEMS FIXED BY R13C3
=======================-

  - General Issues
  - Dimensioning Issues
  - Text and Font Issues
  - ASE Issues
  - Plotting and Driver Issues
  - Customization, AutoLISP, and ADS Issues

This section explains the problems that are fixed with the R13c3
update.

General Issues
==============-

      - BHATCH no longer detects objects on frozen layers.

      - Unreferenced unnamed blocks are now purged automatically.

      - Elliptical arcs can now be stretched.

      - The SAVE command no longer changes the name of the current
drawing unless it is unnamed. It now writes a copy of the current
drawing to a new file.

      - The time required to compile a menu file has been decreased.

      - DXFIN properly imports a drawing with xref/bind that contains
complex linetypes.

      - Multiple saves to a network drive work properly now.


Dimensioning Issues
===================-

      - DIMCONTINUE and DIMBASELINE do not recognize a previous
dimension after a UCS change. They also will not reference a
previously deleted dimension.

      - The LEADER command now uses the correct arrowhead style and
honors all dimension overrides. The LEADER command correctly allows
the use of an exploded block as annotation.

      - Leader objects now correctly honor the setting of DIMCLRT.

      - The DIMTOL and DIMLIM dimension variables are mutually
exclusive Boolean system variables. Both may be false, but if one is
set to true the other is set to false.


Text and Font Issues
====================-

      - AutoCAD no longer ignores trailing spaces for right and middle
justified text.

      - Mtext created in a rotated UCS in AutoCAD for Windows is now
properly oriented.

      - The handling of bigfonts has been improved. The opening of R12
drawings with custom bigfonts are handled correctly and Unicode
symbols properly display with bigfonts.

      - The TXT.SHX font has been modified to reduce the space
following the "i" and "l" characters.

      - Special characters in BIGFONT.SHX now display correctly. For
example, the BIGFONT.SHX file properly displays the diameter symbol
when used with the ROMANS.SHX font.


ASE Issues
==========-


      - ASI and ASE can now use the PARADOX driver concurrently.

      - The asi_setcfg function now correctly handles two arguments,
as documented.


Plotting and Driver Issues
==========================-

      - PSOUT now properly sizes text regardless of the text rotation.

      - When plotting to a file with CMDDIA=0, AutoCAD correctly
overwrites the existing file (if any)

      - The PostScript plot driver correctly handles the plotting of
dotted lines and dots in lines.

      - The Summasketch III 1212 and 1218 DOS and wintab digitizer
drivers work properly now.


Customization, AutoLISP, and ADS Issues
=======================================-

      - Menu swapping of the POP, AUX, and BUTTONS areas works
properly now. The pipe symbol "|" is now allowed in menu macros.

      - Embedded comments are now acceptable anywhere in an AHP file.

      - The AutoLISP function ai_propchk has been changed to c:ai_prop
so that it behaves similarly to other commands. This allows pressing
return to bring back DDMODIFY if selected from toolbar.

      - Dimensions without a dimension style (from a pre-R13 drawing)
use a null string as the group code 3 value.

      - Using the AutoLISP or ADS entmod function on an attribute
created in R12 or on a frozen layer works properly now.

      - A semantic change to ssget "X" filtering: Previously, there
was no sense of literal matching -- the only filtering was via
wildcards. As a result, one could (for example) create a text string
reading "Hi, Joe!"; but attempting to filter on that string would
fail, because the comma was treated as a wildcard character. Now
literal matching occurs first; only if the literal match fails is
wildcard matching attempted.

      - Bit 3 (library search) of the getfiled function works properly
now.

      - The message dialog that appears when loading an MNU file from
the MENU and MENULOAD commands no longer interrupts a script or
AutoLISP function.

      - The use of a transparent command after an (ssget "F") no
longer causes an unhandled exception.

      - (c:stats nil) properly turns off statistics logging.

      - AutoLISP and ADS entget, now properly returns the group code
11.

      - The ads_printf() function now works properly with a null
string argument.

      - The WINADS.BAT and WINADS.MAK files now work properly with
Visual C++ 2.0.



=====================================================================-
PLATFORM INDEPENDENT INFORMATION
================================-

  - Contacting Autodesk
  - RAM Requirements
  - Undo File on Disk
  - Extrusion and Elevation Change of Solids and Other Objects
  - Incremental Save Feature
  - Release 12 Compatibility Issues


Contacting Autodesk
===================-


Autodesk on the Web
-------------------
Autodesk's Web site on the Internet is accessible via a Web Browser at
http://www.autodesk.com.  Information is organized in twelve
categories, including What's New, About Autodesk, Products, Product
Support, Market Groups, Education and Training, Government, User
Groups, Developers, Job Search, Interviews and Send Us Your Thoughts.



AutoCAD Technical Publications
------------------------------
You can contact the AutoCAD Technical Publications department with any
comments, suggestions, or problems regarding the AutoCAD documentation
by sending an email to acad_docs@autodesk.com.


RAM Requirements
================-
DOS            12 Mb minimum

Windows        16 Mb minimum
               64 Mb permanent swap file

NT             32 Mb recommended
               64 Mb permanent swap file

In all cases, these recommendations assume typical drawing file sizes
up to 1Mb. Additional memory is recommended for larger drawing file
sizes or when running multiple applications.


Undo File on Disk
=================-
      The Undo file (the record of all actions since opening the
drawing) was previously maintained in RAM. This reduced the amount of
available swap space and RAM. The UNDOONDISK system variable was added
to allow users the ability to specify whether the Undo file is
maintained in RAM or on the hard disk. The default setting (1)
specifies that this file is kept on the hard disk. See the Manual
Corrections and Additions, AutoCAD Command Reference section for
details.

Extrusion and Elevation Change of Solids and Other Objects
==========================================================-
      It is not recommended that spline objects or 3dsolid, body, or
region objects that contain a spline as one of their faces or edges,
be extruded to a very large value (greater than 1e19). In some cases
(specifically on the NT platform) a crash can occur and AutoCAD will
exit without giving the user a chance to save the drawing. This can
also occur when you change the elevation of these objects to a very
large value (such as 1e23).

If you must perform this type of extrusion or elevation change we
recommend that you save the drawing prior to performing the operation.

Incremental Save Feature
========================-
      Incremental save is a new feature that provides the ability to
save only the changes made to a drawing. So, if a drawing is opened,
and only a few edits are done, and a SAVE is performed, the save
operation will be fast. The way this feature has been implemented,
it's use should be transparent to the user. For example, the SAVE and
SAVEAS commands will automatically cause an incremental save when
possible.

In order to be able to save incremental changes to a drawing file, the
drawing must first be saved through a full save. Once the initial save
has been performed, the drawing is now a candidate for incremental
saves.

There are internal and external controls that determine when an
incremental save is performed as opposed to a full save. A full save
is when all of the data in the current database is written out (as
opposed to only the changed information). Internally, there are
thresholds for the fraction of change to the database, and the total
number of objects changed, which, when exceeded, causes a full save.

Externally, the user has control through the ISAVEPERCENT system
variable. This is an integer between 0 and 100. It represents the
amount of wasted space that will be tolerated in the drawing file.
This is needed since incremental save, for the most part, appends new
data to the end of the drawing file. It does try to reuse space within
the file where possible, especially for large objects, but dead space
within the file is inevitable. The default value of this variable is
50 - which means that the *estimate* of wasted space within the file
should not exceed 50% of the total file size. If the estimate exceeds
50%, the next save will be a full save, which resets the wasted space
estimate to zero. If ISAVEPERCENT is set to 0, this means a save will
always result in a full save.

If the user does several incremental saves, and is concerned about the
file size growth, simply setting ISAVEPERCENT to 0, doing a SAVE or
SAVEAS, and setting it back to 50 (or it's previous value) will get
rid of the wasted space.

For values of ISAVEPERCENT less than 20, the estimate of wasted space
is a bit more accurate - but this comes at an expense of time, i.e.
incremental saves will take longer for values of ISAVEPERCENT less
than 20.

Another system variable, ISAVEBAK, can be used to improve the speed of
incremental save, especially for larger drawings on the Windows
platform. ISAVEBAK controls whether a .BAK file needs to be created or
not. This variable was added because, on the Windows platform, copying
the file data to create a .BAK file for large drawings takes a major
portion of the incremental save time. ISAVEBAK has the default setting
of 1 (always create a .BAK, as in R12). By setting it to 0, SAVE will
no longer create a .BAK, even for a full save.

Caution: Use this feature with care, because, by setting ISAVEBAK to
    0, a .BAK file is no longer created. So, in the case of a
    contingency (e.g. power failure in the middle of a save), it is
    possible that the drawing data can be lost.

Another tip to improve incremental save performance is to set the
system variable RASTERPREVIEW to 3. This avoids having to save the
preview image for every incremental save, and results in a noticeable
improvement for incremental saves, especially when a lot of graphics
are displayed in the current views.


Release 12 Compatibility Issues
===============================-


Using Release 12 Files in Release 13
------------------------------------
When you open a Release 12 drawing file in Release 13, it is converted
to Release 13 format. Release 12 drawings display differently as they
are loaded into Release 13 than do Release 13 drawings. Release 12
drawings regenerate after they are loaded into memory, causing a delay
before you see anything drawn on screen. Release 13 drawings
regenerate as they are being loaded.

In the unlikely event that Release 13 crashes, you will be prompted
with the option to save the drawing. If you respond with a Yes, the
drawing is saved in R13 format and will require recovery (done
automatically during the OPEN process). It is important to note that
the original drawing is renamed with a .BAK extension and can be
opened after renaming it with a .DWG extension.

If you need to keep the drawing in Release 12 format, either mark the
file as "read only," or load it into Release 13 and use the SAVEASR12
command to save it to a file in Release 12 format.


=====================================================================-
WINDOWS-SPECIFIC INFORMATION
=============================-

  - AutoCAD WHIP Display List Driver
  - Use Version 1.25 of Win32s
  - Using ADS and ARX Applications
  - Moving an Electronic Document to Hard Disk


AutoCAD WHIP Display List Driver
=================================-
      After installing/configuring the AutoCAD WHIP display list
driver, refer to the Online Help file accessed from the driver
configuration dialog for additional details concerning the
functionality of the driver.

The WHIP driver is designed to work with the c2 and c3 releases of
AutoCAD. In addition, this driver should also work with the c0 and c1
releases, however it has not been tested. The WHIP driver has been
optimized for performance with 256 color display devices. While
performance should still be quite good with 16 or greater than 256
color devices, it is recommended that a 256 color configuration be
used with the WHIP driver.

The WHIP driver's performance improvements are partly the result of an
off-screen bitmap. This bitmap requires approximately 1 megabyte of
additional RAM. Therefore, it is recommended that you increase system
memory in order to accommodate drawings that exceed 1 megabyte.

Because of the off-screen buffer used by the WHIP driver to improve
performance, AutoCAD applications which write directly to the frame
buffer may produce unexpected results when used with the WHIP driver.
Similarly, applications that send ADI packets directly to the driver
may encounter problems. Softdesk's CAD Overlay is one product that is
known to be incompatible with the WHIP driver.

If you have an application that does not appear to be working
correctly with the WHIP driver, it is recommended that you reconfigure
AutoCAD to use the Accelerated driver from Rasterex, or use an
independently developed accelerated driver.


Microsoft WinG Installation
---------------------------
To use the WHIP display list driver, you must first install WinG. WinG
version 1.0, included with the WHIP driver, is a performance
enhancement from Microsoft that provides faster display access in a
Microsoft Windows or Windows for Workgroups environment.

The AutoCAD WHIP driver does not require WinG if you are using
Microsoft Windows NT 3.5. Installation of WinG under NT is allowed,
but is not used by the WHIP driver.

To install WinG:

1.  Insert the AutoCAD R13c3 CD or the diskette labeled Microsoft
    WinG into the appropriate drive, or change to the directory that
    contains the WinG SETUP.EXE file if you received WinG
    electronically.
2.  From the Windows Program Manager, choose Run from the File menu
    and enter the following (specifying the appropriate floppy or CD
    drive letter):
          a:\wing\setup.exe
3.  Follow the prompts to complete the installation.

Note: The first time you install/configure a new video display driver,
    WinG runs a performance test to determine the fastest way to
    transfer a Bitmap to the display. This test takes a few minutes,
    and only happens once (unless you change your video mode).


Interactive Pan & Zoom
----------------------
The C3 patch to AutoCAD R13 provides two commands, RTPAN and RTZOOM,
to perform interactive panning and zooming. These pan and zoom
features are only intended for use with the WHIP display driver or a
high performance independently developed display driver. A slower
display driver will impact the performance of these features.

When the RTPAN and RTZOOM commands are active, no other AutoCAD
commands can be executed.

Note: RTPAN and RTZOOM are provided specifically for Release c3.
    Future compatibility with these commands is not guaranteed. For
    example in AutoCAD Release 14, this functionality may be merged
    into improved versions of previously existing commands.

MENU CONFIGURATION

To interact with RTPAN and RTZOOM, you must load the .mnu file to add
these features to the toolbar. Use the following procedure to add the
RTPAN/RTZOOM toolbar menu.

1.  From the Tools menu, choose Customize Menus.
2.  From the Menu Customization dialog box, enter rtpanzm.mnu in the
    File Name edit box.
3.  Choose LOAD.
4.  Choose CLOSE.

You can also enter MENULOAD from the command line to access the Menu
Customization dialog box.

The following sections describe the functionality of interactive
panning and zooming.


PANNING

To pan, enter RTPAN or select the hand icon from the RTPAN/RTZOOM
toolbar. The cursor changes to a hand cursor. By holding the pick
button down, the cursor is locked to its current location relative to
the drawing viewport display coordinate system. Graphics within the
window are moved in the same direction along with the cursor.

When you have reached a logical extent (edge of the drawing space), a
bar appears on the cursor indicating the side where the extent has
been reached. Depending upon whether the logical extent reached is at
the top, bottom, or side of the drawing, the bar that appears is
either horizontal (top or bottom), or vertical (left or right side).

When you release the pick button, panning is discontinued. You can
release the pick button, move the cursor to another location in the
