@DATABASE "wpg.datatype.guide"
@$VER: wpg.datatype.guide 39.0 (19.4.95)
@AUTHOR "Arthur Pijpers"
@NODE Main "wpg.datatype Documentation"
@{B}Table of Contents@{UB}
@{" Legal                                  " link Legal}
@{" Introduction                           " link Introduction}
@{" Requirements                           " link Requirements}
@{" How to Install                         " link Installation}
@{" What is a wpg file ?                   " link wpg }
@{" Implementation Details (Release Notes) " link Implementation}
@{" Revision history                       " link History}
@{" Acknowledgements                       " link Acknowledgements}
@{" Author                                 " link Author}
@ENDNODE
@NODE Introduction
@{B}Introduction@{UB}
This is V39.0 of the @{"wpg" link wpg} datatype. The version information can be verified
by using the AmigaDOS @{B}version@{UB} command on the datatype file
SYS:classes/datatypes/wpg.datatype after installation.
Once installed, the wpg datatype means that any datatype-aware programs can
read @{"wpg" link wpg} image files.
Examples of this are that a wpg image can be used as a Workbench screen
backdrop, and Multiview can be used to display them.
@ENDNODE
@NODE Legal
@{B}Legal@{UB}
The wpg datatype is freely distributable, but you may not charge for it,
other than for reasonable media and distribution costs such as those charged
by Fred Fish, the Aminet CD and other reputable PD libraries.
The wpg datatype can be distributed as part of a datatype collection, but
then you have to supply both the 68000 and the 68020 version.
If you really use this datatype, please send me some E-Mail. I'd like to know
if people really use these things.
@ENDNODE
@NODE Requirements
@{B}Requirements@{UB}
Datatypes were introduced with Workbench 3.0, so the main requirement is
that you have this version of the OS. Presumably, any future versions of the
OS will also support them.
Do not try to install the datatype if you are using an OS older than 3.0
(i.e. 1.3, 2.04, or 2.1).  The correct directories do not exist, and nothing
will work even if you create them.  I'm afraid you'll have to find some
other program to view your @{"wpg" link wpg} files with.
When you use the datatype on a computer without the AGA chipset, then 
pictures with more than 16 colours are automatically dithered to the
maximum number of available colours, unless you have a graphical card added.
@ENDNODE
@NODE Installation
@{B}How to Install@{UB}
Installation can be done in one of two ways:
1) Using Installer
2) Manual Installation
If you have a copy of Installer, you can simply double click on the
wpg.datatype.install icon and follow the onscreen instructions. The
Installer script follows the manual sequence below, so you are advised to
read it quickly so that you know what to expect.
If you do not have Installer, (which is strange, because you have
Workbench 3), then follow the procedure below:
1) Copy the file wpg.datatype.68000 or wpg.datatype.68020 to the directory
SYS:classes/datatypes and rename it to wpg.datatype (SYS: is a logical name
for the disk you boot from).  You can perform the copy either from the
Workbench or the Shell. Use the 68020 version only on Amigas with a 68020
processor or higher.
2) Decide whether you want the datatype to be permanently enabled, or
manually run whenever you want to use it.  Proceed to step 3 for a
permanently enabled installation, otherwise proceed to step 4.
3) Copy the file "WPG" to the directory DEVS:Datatypes (DEVS: is a
logical directory on the disk you boot from.  It is the same as the DEVS
drawer on the boot disk).  If using the Shell, you will also have to
manually copy the icon file "wpg.info".  When you reboot your system,
the wpg datatype will be avaliable for use.
4) Copy the file "WPG" to the directory SYS:Storage/Datatypes. If
using the Shell, you will also have to manually copy the icon file
"wpg.info".
The wpg datatype will not be available until you double click on the
"WPG" icon, at which point it will remain installed until a reboot.
This completes installation.
@ENDNODE
@NODE wpg
@{B}What is a wpg file ?@{UB}
A wpg file is a graphical file. It is used by WordPerfect in most of
their programs. A wpg file can contain bitmap graphics, but also vector
graphics and other information. Only the bitmap is supported. Other
information is ignored.
@ENDNODE
@NODE Implementation
@{B}Implementation Details (Release Notes)@{UB}
These are the release notes for V39.0 of the wpg datatype.
This implementation will decode @{"wpg" link wpg} bitmap files in up to 256
colours. Vector images are not supported.
If you are using Multiview to display @{"wpg" link wpg} files without the SCREEN
tooltype/parameter, the @{"wpg" link wpg} file will be displayed in a window on the
Workbench, it will be quantised down to however many colours you have set up
on your Workbench screen.
If you are using Multiview with the SCREEN tooltype/parameter, the datatype
will choose the screen resolution that it thinks is most appropriate for
displaying the image from the selection available in the display database.
This decision is made using the BestModeID function, and is based on the
size, colour count and aspect ratio of the image.
@ENDNODE
@NODE History
@{B}Revision History@{UB}
Version 39.0 released 19-4-1995
 - First release
@ENDNODE
@NODE Acknowledgements
@{B}Acknowledgements@{UB}
Many thanks to John Hendrikx (Textdemo/FastView) for the Chunky2Planar
routine.
Thanks to Kees Huizer for uploading this to Aminet
wpg datatype was compiled using SAS/C V6.55
@ENDNODE
@NODE Author
@{B}Author@{UB}
Arthur Pijpers
Please feel free to contact me at:
Usenet  : arthurp@grafix.xs4all.nl
FidoNet :  2:286/407.37
AMYNet  : 39:153/201.37
NLANet  : 14:101/200.37
@ENDNODE