bugGnash - The GNU Flash player - Bugs: bug #25835, OGL/accum. buffer dependency...


bug #25835: OGL/accum. buffer dependency (ERROR: OpenGL: invalid operation / flicker)

Submitted by:  Sandro Santilli <strk>
Submitted on:  Thu 12 Mar 2009 09:24:11 AM UTC  
Category:  render-opengl Severity:  3 - Normal
Release:  None Status:  Confirmed
Privacy:  Public Assigned to:  Bastiaan Jacques <bjacques>
Open/Closed:  Open

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( Jump to the original submission)

Mon 16 Mar 2009 03:09:24 PM UTC, comment #8:

The workaround would be to disable antialiasing (what we use the accumulation buffer for), which would actually be faster. But of course you'd have jagged edges.

These days fewer and fewer vendors bother to implement the accumulation buffer, so it is of limited value anyway.

Aside from making anti-aliasing optional, my plan is to create a new GTK glue based using GLUT so we can enable multisample antialiasing, which is the most popular technique these days.

Bastiaan Jacques <bjacques>
Project MemberIn charge of this item.
Mon 16 Mar 2009 02:52:58 PM UTC, comment #7:

Indeed it is reported elsewhere [1] that the intel video chip
doesn't support accumulation buffer.

I get using a workaround would be slower, right ?

[1] http://forum.compiz-fusion.org/showthread.php?p=49070

Sandro Santilli <strk>
Project Member
Mon 16 Mar 2009 01:26:28 PM UTC, comment #6:

The GUI creates the window, so it decides which OpenGL features are enabled. That's probably where the error comment #2 comes from.

Bastiaan Jacques <bjacques>
Project MemberIn charge of this item.
Mon 16 Mar 2009 01:03:40 PM UTC, comment #5:

It seems accumulation buffer is available for some of my configurations:

36 GLXFBConfigs:
visual x bf lv rg d st colorbuffer ax dp st accumbuffer ms cav
id dep cl sp sz l ci b ro r g b a bf th cl r g b a ns b eat
0x54 0 tc 0 32 0 r . . 8 8 8 8 0 0 0 0 0 0 0 0 0 None
0x55 0 tc 0 32 0 r . . 8 8 8 8 0 0 0 16 16 16 16 0 0 Slow

How is a GLXFBConfig selected by our renderer ? (or, is it?)

Sandro Santilli <strk>
Project Member
Fri 13 Mar 2009 11:39:24 PM UTC, comment #4:

Yes, the renderer assumes the accumulation buffer is available even when it isn't. So the renderer should make sure it is before it attempts to use it.

Bastiaan Jacques <bjacques>
Project MemberIn charge of this item.
Fri 13 Mar 2009 03:27:53 PM UTC, comment #3:

Any hint on where to look at in order to fix this bastiaan ?

Sandro Santilli <strk>
Project Member
Thu 12 Mar 2009 09:31:43 AM UTC, comment #2:

The almighty elvis.swf also results in that ERROR printed, and nothing is rendered after the initial loading bar (which flickers itself).

Sandro Santilli <strk>
Project Member
Thu 12 Mar 2009 09:30:14 AM UTC, comment #1:

Same error with the attached movie bitmap.swf (smaller, and produced for testing purposes by Udo again).

Also, I saw this other error is printed:
ERROR: Cannot find the double-buffered visual. Trying single-buffered visual.

(file #17663)

Sandro Santilli <strk>
Project Member
Thu 12 Mar 2009 09:24:11 AM UTC, original submission:

Testcase: magical trevor
File: 6964trev3c.swf
md5sum: ea8bbad50ccbc52dd734dfc93a7f06a7

The visible symptom is a continuos flickering during animation.
Works fine with AGG renderer.

Sandro Santilli <strk>
Project Member


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:

Attached Files
file #17663:  bitmap.swf added by strk (20KiB - application/x-shockwave-flash)


Depends on the following items: None found

Items that depend on this one: None found


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  • -email is unavailable- added by bjacques (Updated the item)
  • -email is unavailable- added by strk (Submitted the item)

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    Follow 3 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2009-03-12 strk Attached File- => Added bitmap.swf, #17663
    2009-03-12 bjacques StatusNone => Confirmed
        SummaryMagicalTrevor: ERROR: OpenGL: invalid operation => OGL/accum. buffer dependency (ERROR: OpenGL: invalid operation / flicker)

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