This is the mail archive of the cygwin-xfree mailing list for the Cygwin XFree86 project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: X hardware acceleration still flaky?

On 10/08/2010 12:00, wrote:
Program received signal SIGSEGV, Segmentation fault.
[Switching to thread 5736.0x16c4]
0x6fb96c8d in pixman_fill_sse2 () from /usr/bin/cygpixman-1-0.dll
(gdb) bt
#0  0x6fb96c8d in pixman_fill_sse2 () from /usr/bin/cygpixman-1-0.dll
#1  0x6fb97205 in pixman_fill_sse2 () from /usr/bin/cygpixman-1-0.dll
#2  0x6fb77245 in pixman_fill () from /usr/bin/cygpixman-1-0.dll
#3  0x0044924b in fbFill (pDrawable=0x109306f8, pGC=0x10936530, x=657, y=367,
     width=450, height=450) at fbfill.c:48
#4  0x0044746f in fbPolyFillRect (pDrawable=0x109306f8, pGC=0x10936530,
     nrect=0, prect=0x1096791c) at fbfillrect.c:77
#5  0x0052728f in damagePolyFillRect (pDrawable=0x109306f8, pGC=0x10936530,
     nRects=1, pRects=0x10967914) at damage.c:1404
#6  0x005504c3 in ProcPolyFillRectangle (client=0x106bd4f0) at dispatch.c:1939
#7  0x0054c56e in Dispatch () at dispatch.c:439
#8  0x005465af in main (argc=3, argv=0x61227b64, envp=0x104300f8)
     at main.c:286


With the details provided in the last couple of emails, I have managed to reproduce what I think is the same problem as you are seeing.

1) Start geomview
2) Cause the geomview camera window to start animating, e.g. by loading one of the demo scenes and making the camera rotate, or by opening SaVi and starting simulated time running
3) Move the camera window away from it's original position up or to the left (observe if you move it a small amount to the right or down, the area of scene being drawn in it which is updated is constrained to the original window position)

This has nothing to do with 'hardware acceleration' or OpenGL, it seems that the particular way this application draws it's output (into a same-size child window of the camera window) interacts with the composite extension to expose a bug in the XWin code.

You should be able to workaround the crash by starting the X server with '-extension Composite' to disable the composite extension.

I've uploaded a build with an attempt at fixing this at [1]. Perhaps you could try it out and see if it works for you?

I'm not sure why the image flickers so badly, a double buffered OpenGL visual seems to be being used, so only a complete frame should be transferred to the display, but I can see elements of the scene being drawn.


Volunteer Cygwin/X X Server maintainer

Unsubscribe info:
Problem reports:

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]