If NULL is returned by vkGetDeviceProcAddr(), either the driver
is buggy, either the wlroots code is buggy. For a valid device and
command name, drivers are not allowed to return NULL per the spec.
This mirrors what the GLES2 renderer does in load_gl_proc().
Instead of filling the fields one by one, use a struct initializer.
This avoids repeating the name of the variable and is more
consistent with the wlroots code style.
find_extensions() is clunky to use when checking only a single
extension, and it's surprising that it returns NULL on success.
Simplify by replacing it with a check_extension() function which
just checks whether a single extension is in the list.
This new renderer is implemented with the existing wlr_renderer API
(which is known to be sub-optimal for some operations). It's not
used by default, but users can opt-in by setting WLR_RENDERER=vulkan.
The renderer depends on VK_EXT_image_drm_format_modifier and
VK_EXT_physical_device_drm.
Co-authored-by: Simon Ser <contact@emersion.fr>
Co-authored-by: Jan Beich <jbeich@FreeBSD.org>