[Mesa-dev] OSMesa Virtual Window with height > 16384px

[Brian Paul]

On 09/23/2016 08:08 AM, Phaedra Narayna wrote:
> Hi,
>
> I have a OSMesa bug when trying to create a virtual window that is more
> than  16384 pixel in height , see below :
>
> *Command:*
> #headless_shell --screenshot --window-size="1920x16385"
> --hide-scrollbars --no-sandbox http://linuxfr.org
> *Error Msg:*
> [0920/154515:ERROR:gl_context_osmesa.cc(72)] OSMesaMakeCurrent failed.
> [0920/154515:ERROR:gles2_cmd_decoder.cc(4992)] GLES2DecoderImpl: Context
> lost because context no longer current after resize callback.
> [0920/154515:ERROR:gles2_cmd_decoder.cc(5108)] Error: 5 for Command
> kResizeCHROMIUM
> [0920/154515:ERROR:gl_context_osmesa.cc(72)] OSMesaMakeCurrent failed.
>
> I am using OSMesa on Archlinux :
> https://www.archlinux.org/packages/extra/i686/mesa/ , mesa 12.0.3-1 as
> this time of writing.
>
> I have checked with the HeadLess Chromium project as per this thread:
> https://groups.google.com/a/chromium.org/forum/#!topic/headless-dev/t0ixeHXCzK0
>
> I have checked with the Skia project as per this thread :
> https://bugs.chromium.org/p/skia/issues/detail?id=580&can=2&start=0&num=100&q=label%3AHotlist-Fixit&colspec=ID%20Type%20Status%20Priority%20M%20Area%20Owner%20Summary&groupby=&sort=
>
>
> Any idea on how to solve this problem?

There's always a limit on max surface/rendering size because of 
rasterization and interpolation limitations.

I don't know which driver you're using, but if you query the 
GL_MAX_FRAMEBUFFER_WIDTH and GL_MAX_FRAMEBUFFER_HEIGHT you can find the 
limits.

If you need to render a larger image, you'll probably have to break up 
the image into tiles which are rendered individually.  Here's an old 
project of mine that might help:  http://www.mesa3d.org/brianp/TR.html

-Brian