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

2 files changed, 11 insertions, 11 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;
 	}
diff --git a/backend/drm/renderer.c b/backend/drm/renderer.c
index 7e2b5174..d5bcef2b 100644
--- a/backend/drm/renderer.c
+++ b/backend/drm/renderer.c
@@ -19,29 +19,28 @@
 #endif
 
 bool init_drm_renderer(struct wlr_drm_backend *drm,
-		struct wlr_drm_renderer *renderer) {
+		struct wlr_drm_renderer *renderer, wlr_renderer_create_func_t create_renderer_func) {
 	renderer->gbm = gbm_create_device(drm->fd);
 	if (!renderer->gbm) {
 		wlr_log(L_ERROR, "Failed to create GBM device");
 		return false;
 	}
 
-	if (!wlr_egl_init(&renderer->egl, EGL_PLATFORM_GBM_MESA, renderer->gbm,
-			NULL, GBM_FORMAT_ARGB8888)) {
-		goto error_gbm;
+	if (!create_renderer_func) {
+		create_renderer_func = wlr_renderer_autocreate;
 	}
 
-	renderer->wlr_rend = wlr_gles2_renderer_create(&renderer->egl);
+	renderer->wlr_rend = create_renderer_func(&renderer->egl,
+		EGL_PLATFORM_GBM_MESA, renderer->gbm, NULL, GBM_FORMAT_ARGB8888);
+
 	if (!renderer->wlr_rend) {
-		wlr_log(L_ERROR, "Failed to create WLR renderer");
-		goto error_egl;
+		wlr_log(L_ERROR, "Failed to create EGL/WLR renderer");
+		goto error_gbm;
 	}
 
 	renderer->fd = drm->fd;
 	return true;
 
-error_egl:
-	wlr_egl_finish(&renderer->egl);
 error_gbm:
 	gbm_device_destroy(renderer->gbm);
 	return false;