render/egl: improve modifier support detection

Support for EXT_image_dma_buf_import_modifiers doesn't necessarily
indicate support for modifiers. For instance, Mesa will advertise
EXT_image_dma_buf_import_modifiers for all drivers. This is a trick
to allow EGL clients to enumerate supported formats (something
EXT_image_dma_buf_import is missing). For more information, see [1].

Add a new wlr_egl.has_modifiers flag which indicates whether
modifiers are supported. It's set to true if any
eglQueryDmaBufModifiersEXT query returned a non-empty list.

Use that flag to figure out whether the buffer modifier should be
passed to the EGL implementation on import.

[1]: https://github.com/KhronosGroup/EGL-Registry/issues/142

1 files changed, 1 insertions, 0 deletions

diff --git a/include/wlr/render/egl.h b/include/wlr/render/egl.h
index 2af073ca..0d84958b 100644
--- a/include/wlr/render/egl.h
+++ b/include/wlr/render/egl.h
@@ -65,6 +65,7 @@ struct wlr_egl {
 		PFNEGLQUERYDEVICESEXTPROC eglQueryDevicesEXT;
 	} procs;
 
+	bool has_modifiers;
 	struct wlr_drm_format_set dmabuf_texture_formats;
 	struct wlr_drm_format_set dmabuf_render_formats;
 };