[Mesa-dev] Extension help

[Fritz Koenig]

Hi,

I would like to be able to use the MESA_framebuffer_flip_y extension
in GLES 3.0.  The blocker is that FramebufferParameteri is not part of
GLES 3.0.  I have explored a couple of ways of achieving this.

1.   FramebufferParameteri was first provided by the GL extension
ARB_framebuffer_no_attachments.  However,
ARB_framebuffer_no_attachments was never a GLES extension.  An option
would be to modify the ARB_framebuffer_no_attachments spec to make it
an extension for GLES.

2.  Change the MESA_framebuffer_flip_y spec to allow the extension to
implement FramebufferParameteri.

I choose the 2nd option and put together a pr for it[1].

I didn't get the implementation quite right, and I'm looking for some
help.  My change is failing the DispatchSanity_test.GLES3 test:

[ RUN      ] DispatchSanity_test.GLES3
../src/mesa/main/tests/dispatch_sanity.cpp:174: Failure
      Expected: nop_table[i]
      Which is: 0x563d50d6fa01
To be equal to: table[i]
      Which is: 0x563d50db158a
i = 888 (FramebufferParameteri)
../src/mesa/main/tests/dispatch_sanity.cpp:174: Failure
      Expected: nop_table[i]
      Which is: 0x563d50d6fa01
To be equal to: table[i]
      Which is: 0x563d50db1add
i = 889 (GetFramebufferParameteriv)
[  FAILED  ] DispatchSanity_test.GLES3 (1 ms)

It appears there is a problem with the way that I'm
defining/redefining FramebufferParameteri.  I've tried adding it to
src/mapi/glapi/gen/es_EXT.xml, but the only way I was able to achieve
that was to give it a different function name and an alias.

Does anyone have experience with this sort of backporting of
extensions that could offer some insight on what I might be doing
wrong?

Thanks.

-Fritz

[1]: https://gitlab.freedesktop.org/mesa/mesa/merge_requests/1560