backends: implement custom EGL and renderer initialization

Compositors now have more control over how the backend creates its
renderer. Currently all backends create an EGL/GLES2 renderer, so
the necessary attributes for creating the context are passed to a
user-provided callback function. It is responsible for initializing
provided wlr_egl and to return a renderer. On fail, return 0.

Fixes #987

1 files changed, 3 insertions, 2 deletions

diff --git a/backend/drm/backend.c b/backend/drm/backend.c
index c14b99e3..744a32d2 100644
--- a/backend/drm/backend.c
+++ b/backend/drm/backend.c
@@ -114,7 +114,8 @@ static void handle_display_destroy(struct wl_listener *listener, void *data) {
 }
 
 struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
-		struct wlr_session *session, int gpu_fd, struct wlr_backend *parent) {
+		struct wlr_session *session, int gpu_fd, struct wlr_backend *parent,
+		wlr_renderer_create_func_t create_renderer_func) {
 	assert(display && session && gpu_fd >= 0);
 	assert(!parent || wlr_backend_is_drm(parent));
 
@@ -161,7 +162,7 @@ struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
 		goto error_event;
 	}
 
-	if (!init_drm_renderer(drm, &drm->renderer)) {
+	if (!init_drm_renderer(drm, &drm->renderer, create_renderer_func)) {
 		wlr_log(L_ERROR, "Failed to initialize renderer");
 		goto error_event;
 	}