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Aminet 21 (1997)(GTI - Schatztruhe)[!][Oct 1997].iso
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QRT_V43DT.lha
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qrtV43Datatype
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qrtV43.datatype Version 43.1 (4-Jul-97)
and fixed descriptor for qrt.datatype (qrtV39Fix).
Written by TetiSoft@apg.lahn.de (Detlef Wuerkner)
This is public domain.
It's a datatype for PovRay dump format (QRT). V43 only, that means,
it requires a 24-Bit picture.datatype (currently available for
Cybergraphics and Picasso96). If your picture.datatype is an older
version, don't worry, this package contains something that can
be useful for you. See section qrtV39Fix below.
qrtV43
------
Mainly written to see if the samplePNM.datatype and source-code
by Andreas R. Kleinert (V43.6 (27.3.97)) really work as easy as
it seemed. They do ;-) Thanks to Andreas! It's code can be found
on Aminet in dev/c/C_V43DT.lha. Let me cite him:
You may e.g. use this example source code to write more portable
Amiga OS 3 datatypes to allow easier porting of these
to other Amiga OS-derived operating systems, or the native
OS of an upcoming PowerPC Amiga.
The file Source/Part_of_libfuncs.c contains the changed file
decoding function, adopted for QRT format. The descriptor "QRT"
uses the same hook-function as "qrtV39Fix/QRT". The source code
for the hook-function can be found in Source/QRTCheck.c, the
compiled binary is named Source/QRTCheck. When playing around with
"dtdesc", you always must load the fuction Source/QRTCheck before
saving, otherwise dtdesc won't remember it!
Installation of qrtV43:
----------------------
If your picture.datatype has a lower version number than 43, don't
install it, install qrtV39Fix instead!
Copy qrtV43.datatype to SYS:Classes/Datatypes/
Copy QRT and QRT.info to devs:datatypes/
Double-click the QRT-Icon
Try to load "SamplePic" with MultiView to see if it works.
It works? OK, than you don't need the following:
qrtV39Fix
---------
In directory qrtV39Fix you will find a new descriptor for qrt.datatype
39.1 from billy@uni-paderborn.de (Michael Böhnisch), available on aminet
as util/dtype/QRT_DT.lha, that works with older picture.datatypes.
The new descriptor fixes the problem that many non-QRT-Files were
recognized as QRT. It now uses a hook-Function that checks for the
following (citing Michael, who did this tests in the datatype itself):
· File size must match height and width information. Partial files
written by PovRay are rejected.
· Line numbers must start with 0 and increment to image height - 1 in
sorted order. QRT does not explicitly forbid arbitrary line order but
PovRay produces lines in sequence --- take it as a "feature", it really
makes file type detection easier and safer.
The source code for the hook-function can be found in Source/QRTCheck.c,
the compiled binary is named Source/QRTCheck. When playing around with
"dtdesc", you always must load the fuction QRTCheck before saving,
otherwise dtdesc won't remember it!
Installation of qrtV39Fix:
--------------------------
If your picture.datatype has a version number of 43 or higher,
why don't install qrtV43 instead? It would display in 24 bit depth
instead of 8 bit!
To use the fixed descriptor, first install QRT_DT.lha, then copy
qrtV39Fix/QRT#? to devs:datatypes/ and double-click on it. Try to load
"SamplePic" with MultiView to see if it works.
Happy datatyping, and send me an e-mail if this package is of use for you
or if you have problems with it.
TetiSoft@apg.lahn.de (Detlef Wuerkner)