This readme file now follows NELSO line length standard.

  This piece of software is released under the terms of the GNU General
  Public Licence version 2 or, at your choice, any higher version.
  The GNU GPL is included with this package in the file COPYING.

oVDIsis has changed a little from the last snapshot. Since oFBis now takes
care of setting the dev and inq tab returned from v_opn[v]wk and v_extnd.

See NEWS for changes.

All parameters to and from vdi calls go through the VDIPB struct, 
defined in vdidefs.h. This file also contains various standard VDI defines.

To test my functions I've made c bindings for them. These are in the 
vdibind/ directory. They're not really neccessary to have in oTOSis, but they
make testing a lot easier.
The VDIPB struct variable must be called o_vdipb if you use my vdibind.
If you want to test the calls, be sure to have a VDIPARBLK struct and a VDIPB 
struct and copy the VDIPARBLK's members to VDIPB's members, since a VDIPB 
struct doesn't contain the arrays, but only pointers to them. (see otestis.c)

oTOSis should use v_opnwk to open a physical workstation, and a FrameBuffer.
On exit, it should do a v_clswk to close the same. The handle returned from
v_opnwk is the handle the AES call graf_handle should return.

To open a virtual workstation, you need to give a handle to a physical 
workstation to the VDI call v_opnvwk and you will get a unique handle back for 
the virtual workstation, or 0 (zero) if error.

Ok, back to oTOSis. On a trap #2, VDI, a pointer to a VDIPB struct is placed
in D1. This pointer should be the parameter to vdi_call().
That's all you need to do, I hope.

Most programs doesn't use v_opnwk, but only v_opnvwk with the screen handle 
from graf_handle. Therefore oTOSis should initialize the VDI at some point.
Later, oAESis will do this.

The otestis.c program is made so that it's possible to compile the same c file 
both with oVDIsis and normal TOS. Some #ifdefs had to be made. For example, 
in TOS mode, v_opnwk cannot be called to open a physical workstation, since 
one is already open. Instead it gets the handle from graf_handle, the way it 
should be. Later, when oAESis is used, a testprogram would do it the TOS way. 
I've made otestis.c compile in PureC for TOS mode, but it should be pretty 
easy to use some other compiler as well.

One notable thing you will notice if you run the testprogram in TOS mode and
without NVDI, you will see a difference in the markers. oVDIsis' markers are
more like NVDI's, mostly because they are easier to make and, in my oppinion,
look better.

With oVDIsis, the testprogram is ended by pressing first 'd', then 's'
several times until two colors are changed. After that, 'a' will exit the
program.
  !!!!   With kernel 2.0.21, the key check seems to screw things up for
 !    !  vs_color, and the computer may hang due to fatal error in oFBis.
! NOTE ! This seems to work with 2.0.25, I haven't tried 2.0.22.
 !    !  If you are using an old kernel, you may want to disable the key
  !!!!   check. See top directory Makefile for this.

From version 0.02 of oFBis, it takes care of fatal errors in a better way, so
it shouldn't hang if an error occurs.

See the file FUNCS for a list of all functions, implemented or not, and which
c-file they are in.

They're not complete yet, any of them. v_pline only does 1 pixel wide, no
patterned lines. vr_recfl, v_bar and v_circle only works with solid or hollow.

This snapshot needs oFBis v0.0.5 to work.


That's all, hack loose.


Tomas - tomas@nocrew.org