[Buildroot] Configuring OpenGL

[Peter Seiderer]

Hello Patricia,

On Sun, 20 Dec 2020 19:01:53 -0500, Patricia Holden <pholden at nklabs.com> wrote:

> I know this topic has been visited a couple times, but I did not see my
> particular problem in the threads.  I am trying to add a package that
> requires QT5 components and Gstreamer.  In order to add QT5, openGL is
> required.
>
> Buildroot version I am using is  buildroot-2020-02.
>
> I went into the menuconfig->Libraries->Graphics after looking at
> package/Config.in to find out where I would enable it.  When I got into the
> Graphics libraries, openGL was not an option anywhere in the list.
>
> My question is:  What do I need to do to enable opengl in the menuconfig so
> that I can get my package built and into target?

It depends on your platform and/or graphics hardware. In short your need
an OpenGL provider.

For the long/technical answer take a look at package/qt5/qt5base/Config.in:

 138 comment "OpenGL support needs an OpenGL-capable backend"
 139         depends on !BR2_PACKAGE_QT5_GL_AVAILABLE
 140
 141 config BR2_PACKAGE_QT5BASE_OPENGL
 142         bool "OpenGL support"
 143         depends on BR2_PACKAGE_QT5_GL_AVAILABLE
 144         help
 145           This option enables OpenGL support.

and package/qt5/Config.in:

  1 config BR2_PACKAGE_QT5_GL_AVAILABLE
  2         bool
  3         default y
  4         depends on BR2_PACKAGE_HAS_LIBGL || BR2_PACKAGE_HAS_LIBGLES
  5

So grep for BR2_PACKAGE_HAS_LIBGL or BR2_PACKAGE_HAS_LIBGLES providers:

	$ git grep "select BR2_PACKAGE_HAS_LIBGL"
package/freescale-imx/gpu-amd-bin-mx51/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/freescale-imx/imx-gpu-viv/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/gcnano-binaries/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/mali-t76x/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/mesa3d/Config.in:	select BR2_PACKAGE_HAS_LIBGL
package/mesa3d/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/nvidia-driver/Config.in:	select BR2_PACKAGE_HAS_LIBGL
package/nvidia-driver/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/rpi-userland/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/sunxi-mali-mainline/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/ti-gfx/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/ti-sgx-um/Config.in:	select BR2_PACKAGE_HAS_LIBGLES

	$ git grep "select BR2_PACKAGE_HAS_LIBGLES" | cat
package/freescale-imx/gpu-amd-bin-mx51/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/freescale-imx/imx-gpu-viv/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/gcnano-binaries/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/mali-t76x/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/mesa3d/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/nvidia-driver/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/rpi-userland/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/sunxi-mali-mainline/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/ti-gfx/Config.in:	select BR2_PACKAGE_HAS_LIBGLES
package/ti-sgx-um/Config.in:	select BR2_PACKAGE_HAS_LIBGLES


For example Raspberry Pi hardware there are two options, use
rpi-userland (the old way/32-bit only) or mesa3d/v3d/vc4 (the
new way 32-bit/64-bit)...

Regards,
Peter

>
> Thanks!
> Patricia
>