Re: XWin can't hold OpenGL picture, has WS_DISABLED and WS_EX_TRANSPARENT styles?

[Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>]

On 2019-11-16 06:39, Mick Pearson wrote:
> On Wednesday, November 13, 2019 1:27:53 AM, Mick Pearson wrote:
>> On Saturday, November 9, 2019 3:49:12 AM, Mick Pearson wrote:
>>>> XWin has never had a permanent picture with OpenGL. Any movement "damages" all
>>>> windows. I know I've looked at it before, but I checked its window/class styles
>>>> with MS's Spy++ tool today. The normal styles that govern clipping and
>>>> permanence look fine, but it has some weird styles that normally for disabled
>>>> and transparent windows that I wonder are the cause for its abnormal behavior
>>>> in this regard. No OpenGL apps that just draw only OpenGL on a window have
>>>> XWin's problem.
>>>>
>>>> To be brief, it has these unnatural window-styles in this mail's subject line.
>>>> Other than that, I think it may use Direct3D instead of OpenGL, but normally
>>>> drawing OpenGL or Direct3D onto plain windows doesn't clobber other windows. I
>>>> mean, you have to work hard to make it do something like that.
>>>>
>>>> A second, unrelated, oddity is the window decorations are sometimes classic
>>>> style, and sometimes current style. It's very odd. It's random in the same
>>>> session. The windows seem to undergo a transition from classic to current, but
>>>> get stuck in classic sometimes. Maybe they are using the old "animated" show
>>>> functions that didn't survive the version of Windows that introduced them.
>>>>
>>>> Niggling things like this could be fixed. But I don't know how many people use
>>>> Cygwin. I've used it a lot over the years myself, to do development work. XWin
>>>> is the most stable X server. Others don't really get close. But it's kind of
>>>> too comfortable with its crumminess too. Not that I'm going to shove my work
>>>> aside to try to remedy it myself.

>>> WS_EX_TRANSPARENT styles?
>>> P.S. Sorry to add, the WM_ERASEBKGND message occurred to me, or setting
>>> the class-background to the "null" brush is a likely culprit. It is
>>> behaving like a front-buffered old-fashioned application somewhat.
>>> Clipping and own-DC style should prevent damage, but I don't know,
>>> something seems to be responding to PAINT like events, that don't make
>>> sense for OpenGL.
>> I think I meant to include this>> (https://sourceware.org/bugzilla/show_bug.cgi?id=25170) link that includes
>> this link:>>
>>
https://www.mail-archive.com/search?l=cygwin-xfree@cygwin.com&q=subject:"Re\%3A+Probable+bug+in+WGL+implementation+\(AIGLX\)+of+GLX+calls+in+XWin+\-wgl"&o=newest&f=1
>>
>> I was too zealous to be brief, and I think now the window styles are a red 
>> herring. In any case the problems arise in "overdraw" scenarios wherein a
>> window passes over the OpenGL windows, that is when the background is
>> "erased" and the picture is lose (not held) which makes it impossible to 
>> use XWin for anything but one screen demonstrations of graphical effects.>> Some applications use multiple windows and do rendering with OpenGL instead
>> of GTK widgets for example. Those can't use XWin. I think OpenGL doesn't
>> work with MS Windows X servers. I hope it works with Linux ones.>>
>> The other X servers available to Windows are in disarray with regard to
>> OpenGL.>> So it would be good if one of them could be made to work. XWin is closest
>> since it doesn't crash and does draw correctly other than it can't hold a
>> picture.
> I've put forward a patch
> (https://sourceware.org/bugzilla/show_bug.cgi?id=25170) to this for anyone
> interested. I'll explore putting it elsewhere, but I really think these
> mailing lists are an albatross, not sure I want to join another.
As everyone is a volunteer with little free time, Cygwin no longer uses
sourceware/bugzilla, it uses mailing lists and git format-patch/send-email
patches, to make it quick and easy for committers to apply with git am.
Please submit app patches to cygwin-apps@cygwin.com in git
format-patch/send-email format (with --cover-letter if a patch series).

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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