| Colors and Virtual Machine [message #49153] |
Fri, 30 June 2006 14:32  |
Phillip Bitzer
Messages: 223
Registered: June 2006
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Senior Member |
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OK, IDL gurus, here's another question for you.
I have created (with help from this news group and a couple of David
Fanning's procedures) a GUI for a program that maps out data on map
projection. It works great if I run it from IDL; nice color pic and the
such.
Problem I encounter is when I save it with IDL's save procedure, and
run the program in IDL VM. I get a black and white pic. That is, until
I mouse over a widget_draw widget. Then I get colors all over the
place; the correct colors are in the draw widget, but I also get a
skewing of colors elsewhere on the monitor.
I'm sure I didn't include quite enough info, but I'm hoping this is a
(somewhat) common problem that somebody has encountered before with
some fix that I've overlooked.
Any ideas?
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| Re: Colors and Virtual Machine [message #49229 is a reply to message #49153] |
Wed, 05 July 2006 14:26  |
JD Smith
Messages: 850
Registered: December 1999
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Senior Member |
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On Wed, 05 Jul 2006 21:09:34 +0000, Karl Schultz wrote:
> On Wed, 05 Jul 2006 11:23:31 -0700, JD Smith wrote:
>
>>> [quoted text muted]
>>
>>
>> Hi Karl,
>>
>> This brings up a related but different question. How hard do you guys
>> strive to keep the binary .sav format for compiled code backward
>> compatible? I.e. in statements like "This compiled .sav file requires
>> IDL version 6.2 or later", how far in general will "or later" extend?
>> Within major version number sets (e.g. 6.x?). Or is there any specific
>> policy on this?
>>
>> Obviously, forward compatibility is harder, e.g. allowing a 6.2-compiled
>> .sav to run under v5.X, but this is typically true of source code as
>> well, so there's no real expectation for that to work. However, 99.9% of
>> IDL source code (my guess) is backward compatible --- I'm just wondering
>> how often this compatibility gets broken for the compiled code, due to
>> changes in the .sav format or other ABI issues?
>>
>> JD
>
> Hey JD,
>
> As you know, save files containing data are always compatible.
>
> For code, our docs say that recompilation is needed when the "internal
> code format" changes and goes on to say that the format changed back in
> IDL 5.5 and any save files compiled with IDL versions prior to 5.5 need to
> be recompiled to run with IDL versions 5.5 and later. I think 5.5 was
> about 5-6 years ago.
>
> Major releases tend to coincide with significant functionality
> improvements and it would be too hard to time an internal code format
> change that is needed right now with major feature releases. Although I
> do understand the value of a major version number being associated with a
> stable API/ABI level.
>
> I think that we would advertise very clearly when such a change is made.
> We did so with 5.5. This situation is a lot like changes to the external
> programming interface such as the IDL_STRING string length field. I think
> that we would try very hard to avoid these sorts of changes and make them
> only when there are very good reasons.
Well that doesn't sound so bad. Just so I'm certain I have this
correct, aside from obvious compatibility issues in the source itself
(i.e. if we assume the underlying source code itself would properly
function), any compiled `.sav' produced with IDL>=v5.5 should work
fine with any version of IDL >=v5.5? That's *much* better than I
thought, and greatly reduces concerns of a given `.sav' file's
usefulness as it sits gathering mold in some corner... it's not much worse
than a pile of source code sitting in that corner, and in some ways,
better, since it contains a snapshot of any external library code at a
point of known compatibility.
Thanks,
JD
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| Re: Colors and Virtual Machine [message #49230 is a reply to message #49153] |
Wed, 05 July 2006 14:09 |
Karl Schultz
Messages: 341
Registered: October 1999
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Senior Member |
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On Wed, 05 Jul 2006 11:23:31 -0700, JD Smith wrote:
>> [quoted text muted]
>
>
> Hi Karl,
>
> This brings up a related but different question. How hard do you guys
> strive to keep the binary .sav format for compiled code backward
> compatible? I.e. in statements like "This compiled .sav file requires
> IDL version 6.2 or later", how far in general will "or later" extend?
> Within major version number sets (e.g. 6.x?). Or is there any
> specific policy on this?
>
> Obviously, forward compatibility is harder, e.g. allowing a
> 6.2-compiled .sav to run under v5.X, but this is typically true of
> source code as well, so there's no real expectation for that to work.
> However, 99.9% of IDL source code (my guess) is backward compatible
> --- I'm just wondering how often this compatibility gets broken for
> the compiled code, due to changes in the .sav format or other ABI
> issues?
>
> JD
Hey JD,
As you know, save files containing data are always compatible.
For code, our docs say that recompilation is needed when the "internal
code format" changes and goes on to say that the format changed back in
IDL 5.5 and any save files compiled with IDL versions prior to 5.5 need to
be recompiled to run with IDL versions 5.5 and later. I think 5.5 was
about 5-6 years ago.
Major releases tend to coincide with significant functionality improvements
and it would be too hard to time an internal code format change that is
needed right now with major feature releases. Although I do understand
the value of a major version number being associated with a stable API/ABI
level.
I think that we would advertise very clearly when such a change is made.
We did so with 5.5. This situation is a lot like changes to the external
programming interface such as the IDL_STRING string length field. I think
that we would try very hard to avoid these sorts of changes and make them
only when there are very good reasons.
Karl
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| Re: Colors and Virtual Machine [message #49231 is a reply to message #49153] |
Wed, 05 July 2006 11:23 |
JD Smith
Messages: 850
Registered: December 1999
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Senior Member |
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> No, a 6.0 VM would still have the bug. Your users would have to upgrade
> their VM's.
Hi Karl,
This brings up a related but different question. How hard do you guys
strive to keep the binary .sav format for compiled code backward
compatible? I.e. in statements like "This compiled .sav file requires
IDL version 6.2 or later", how far in general will "or later" extend?
Within major version number sets (e.g. 6.x?). Or is there any
specific policy on this?
Obviously, forward compatibility is harder, e.g. allowing a
6.2-compiled .sav to run under v5.X, but this is typically true of
source code as well, so there's no real expectation for that to work.
However, 99.9% of IDL source code (my guess) is backward compatible
--- I'm just wondering how often this compatibility gets broken for
the compiled code, due to changes in the .sav format or other ABI
issues?
JD
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