screenshots make nexuiz crash

[Fuddl]

hi guys!

taking screenshots by the "screenshot" command make nexuiz crash, if a custom resolution is set. a scrambled, black/white screenshot is written before the engine quits.

i can reproduce that crash on x86 and amd64 by setting vid_width 1270 and vid_height 930. executing the "screenshot" command from the in-game console produces the following output on stdout/stderr:

^7]screenshot
^7Wrote screenshots/nexuiz000005.tga
^7Quake Error: Mem_Free: trashed header sentinel 2 (alloc at cl_screen.c:659, free at cl_screen.c:668)
^7OpenGL Backend shutting down

i know i'm using a very strange resolution ;) but maybe that bug also affects users of wide-screen displays.

cheers - fuddl

[Ed]

Could you try disabling JPEG screenshots and retrying? If it works, the JPEG library being used would be corrupted.

[Fuddl]

it's already disabled: see "^7Wrote screenshots/nexuiz000005.tga"

btw, this applies to the dp engine released within nexuiz 2.0. as i read through the dp source code yesterday, i found out that the crash results from the qglReadPixels() function call in cl_screen.c. if i comment out that call, nexuiz doesn't crash.

[divVerent]

Try this patch: http://t.div0.ccc-offenbach.org/glpackalign.patch

To the others who might be reading this (I know Fuddl doesn't need these instructions): this seems to only happen if the window/fullscreen width is not divisible by four. If it happens for you too, follow the "compile darkplaces from source" instructions posted on this forum somewhere, but before calling make, run:

Code: Select all

  wget -qO- http://t.div0.ccc-offenbach.org/glpackalign.patch | patch -p0


What the change does it calling GL_PACK_ALIGNMENT to disable alignment of screen buffers when reading from video memory, since it defaults to 4-byte alignment, but the following routines expect no alignment.

[Fuddl]

yeeeeehaaaaaa! the patch does the job! thanks, very much!

will that patch be included in the next nexuiz release?

[C.Brutail]

I don't think they would leave it out