Wimp_PlotIcon

[Tony van der Hoff]

On 8 May 2001, you wrote:

> Hello,
> 
> I'm a very satisfied user of OSLib! Thanks for all the work, I
> think it's a very valuable product!
> 
> Unfortunately, I think I found a small problem with it. Well, I
> think so, I'm not really experienced enough to be certain, but it
> is probably a small thing for you guys...
> 
> The problem is this: I am trying to use Wimp_PlotIcon from outside
> a redraw/update loop. It seems not to work. However, I noticed in
> StrongHelp that Wimp_PlotIcon has an R3/R4 that are used as an
> x-offset/y-offset "if outside redraw/update loop", excactly what I
> am doing. However, the PRM doesn't mention R3/R4, at least I can't
> find it. Could it be possible that OSLib doesn't set these to zero
> and therefore give unexpected results? Or is the StrongHelp manual
> wrong (Wimp SWIs manual 1.07)? Haven't before noticed information
> that is wrong, so I really came to trust it... :-)
> 

I don't know about these additional registers in Wimp_PlotIcon; they don't
appear as amendments in PRM 5a, nor do they appear in the RO4 changes. They
appear to have been added to the SH manual in 1998. I would be very surprised
if they had really been newly introduced, as that would break many existing
programs. On the other hand, it may be that Wimp_PlotIcon never properly
worked outside the redraw loop, and this documentation change fixes it. I do
have a note in my PRM that Wimp_PlotIcon doesn't seem to work outside the
redraw loop! However, I am at this stage disinclined to change OSLib on the
basis of the StrongHelp manual alone. That said, other members of this list
may know better, in which case, I'm sure they'll post :-)

If that doesn't help, I suggest that you have two possible courses of action:
first, post the problem to CSAP, and see what others, with more knowledge and
experience than I have to say, and second, temporarily implement the call in
your application using _kernel_swi calls, where you have access to all the
registers, and can try various solutions.

If the problem then turns out to be an omission in OSLib, then I'll certainly
try to fix it.

I'm sorry if this appears to be less than perfect help for your problem.

-- 
Tony van der Hoff         | MailTo:tony at mk-net.demon.co.uk
                          | MailTo:avanderhoff at iee.org
Buckinghamshire, England  | http:mk-net.demon.co.uk