[Bug 5955] DirectDrawCreate crash on non-OpenGL desktop
wine-bugs at winehq.org
Wed Mar 21 17:04:36 CDT 2007
------- Additional Comments From stefandoesinger at gmx.at 2007-21-03 17:04 -------
The winecfg this is easilly answered: There is no winecfg option and there
will never be one. The DirectDraw renderer should be opengl by default, and
autodetected to fall back to gdi if no opengl libs are available, or only
uppon direct request.
The issue that DDraw fails to load completely without opengl is because the
DDraw software renderer is built into wined3d.dll and wined3d.dll is
dynamically linked(at load time) to libGL.so. Having the sw renderer in
wined3d allows us to use it as a fallback if Direct3D blitting
operations(StretchRect, CopyRects) are not supported by the opengl code.
What needs to be done to make DDraw work without gl is to replace the dynamic
load-time linking with lazy linking. The last time this was discussed the idea
was to link wined3d (dynamically) to out opengl32.dll(or native opengl32.dll
on windows). OpenGL32.dll does the lazy linking against libGL.so. For
initialization opengl calls our display driver, winex11.drv or winequartz.drv
which does the platform dependent initialization. Platform independent calls
go from opengl32.dll to libGL.so.
I dislike that idea because I do not think it is good to put abstraction layer
above abstraction layer above abstraction layer in performance critical things
like 3D graphics. In the worst case we have
Also, if I understand the linking concept correctly, dynamic load time linking
results in faster calls than lazy linking. Thus if we take even the simplest
approach and implement lazy linking in wined3d, this will result in decreased
Direct3D performance. It would be a minor decrease, but still a decrease.
Honestly I think that there are more Direct3D users than users who use
DirectDraw on a non-opengl display. I think Gentoo is the only distro that
offers a way to compile wine without opengl, except manual compiling with
fidling with configure params. Keep in mind that you do not need a 3d
accelerator. The Mesa3D software renderer is perfectly enough, and it maybe
even gives faster performance than our software ddraw renderer.
If you want to implement lazy linking to libGL.so the first step would be a
discussion of the approach on wine-devel. My personal preference would be not
to implement lazy linking and close this bug as invalid, or wait for a general
opengl loading cleanup which moves wined3d over to wgl(opengl32.dll), which we
will need if we want to use our (future) Direct3D10 implementation on windows
xp(and thus close the bug as later).
Configure bugmail: http://bugs.winehq.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.
More information about the wine-bugs