commit 5f4c64fbeba941d5dbf4b1467d98c7235e455988
Author: Drew DeVault <sir@cmpwn.com>
Date:   Wed Aug 15 10:56:55 2018 -0400

    Tiny Wayland compositor

diff --git a/tinywl/.gitignore b/tinywl/.gitignore
new file mode 100644
index 00000000..2b5bb6f8
--- /dev/null
+++ b/tinywl/.gitignore
@@ -0,0 +1,3 @@
+tinywl
+*-protocol.c
+*-protocol.h
diff --git a/tinywl/Makefile b/tinywl/Makefile
new file mode 100644
index 00000000..3ecd4670
--- /dev/null
+++ b/tinywl/Makefile
@@ -0,0 +1,24 @@
+WAYLAND_PROTOCOLS=/usr/share/wayland-protocols
+
+xdg-shell-protocol.h:
+	wayland-scanner server-header \
+		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
+
+xdg-shell-protocol.c: xdg-shell-protocol.h
+	wayland-scanner private-code \
+		$(WAYLAND_PROTOCOLS)/stable/xdg-shell/xdg-shell.xml $@
+
+tinywl: tinywl.c xdg-shell-protocol.h xdg-shell-protocol.c
+	$(CC) $(CFLAGS) \
+		-g -Werror -I. \
+		-DWLR_USE_UNSTABLE \
+		$(shell pkg-config --cflags --libs wlroots) \
+		$(shell pkg-config --cflags --libs wayland-server) \
+		$(shell pkg-config --cflags --libs xkbcommon) \
+		-o $@ $<
+
+clean:
+	rm -f tinywl xdg-shell-protocol.h xdg-shell-protocol.c
+
+.DEFAULT_GOAL=tinywl
+.PHONY: clean
diff --git a/tinywl/tinywl.c b/tinywl/tinywl.c
new file mode 100644
index 00000000..101cd53a
--- /dev/null
+++ b/tinywl/tinywl.c
@@ -0,0 +1,620 @@
+#define _POSIX_C_SOURCE 200112L
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+#include <wayland-server.h>
+#include <wlr/backend.h>
+#include <wlr/render/wlr_renderer.h>
+#include <wlr/types/wlr_cursor.h>
+#include <wlr/types/wlr_compositor.h>
+#include <wlr/types/wlr_data_device.h>
+#include <wlr/types/wlr_input_device.h>
+#include <wlr/types/wlr_keyboard.h>
+#include <wlr/types/wlr_linux_dmabuf_v1.h>
+#include <wlr/types/wlr_matrix.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_output_layout.h>
+#include <wlr/types/wlr_pointer.h>
+#include <wlr/types/wlr_seat.h>
+#include <wlr/types/wlr_xcursor_manager.h>
+#include <wlr/types/wlr_xdg_shell.h>
+#include <wlr/util/log.h>
+#include <xkbcommon/xkbcommon.h>
+
+enum tinywl_cursor_mode {
+	TINYWL_CURSOR_PASSTHROUGH,
+	TINYWL_CURSOR_MOVE,
+	TINYWL_CURSOR_RESIZE,
+};
+
+struct tinywl_server {
+	struct wl_display *wl_display;
+	struct wlr_backend *backend;
+	struct wlr_renderer *renderer;
+
+	struct wlr_xdg_shell *xdg_shell;
+	struct wl_listener new_xdg_surface;
+	struct wl_list views;
+
+	struct wlr_cursor *cursor;
+	struct wlr_xcursor_manager *cursor_mgr;
+	struct wl_listener cursor_motion;
+	struct wl_listener cursor_motion_absolute;
+	struct wl_listener cursor_button;
+	struct wl_listener cursor_axis;
+
+	struct wlr_seat *seat;
+	struct wl_listener new_input;
+	struct wl_listener request_cursor;
+	struct wl_list keyboards;
+	enum tinywl_cursor_mode cursor_mode;
+	struct tinywl_view *grabbed_view;
+	double grab_x, grab_y;
+	int grab_width, grab_height;
+	uint32_t resize_edges;
+
+	struct wlr_output_layout *output_layout;
+	struct wl_list outputs;
+	struct wl_listener new_output;
+};
+
+struct tinywl_output {
+	struct wl_list link;
+	struct tinywl_server *server;
+	struct wlr_output *wlr_output;
+	struct wl_listener frame;
+};
+
+struct tinywl_view {
+	struct wl_list link;
+	struct tinywl_server *server;
+	struct wlr_xdg_surface *xdg_surface;
+	struct wl_listener map;
+	struct wl_listener unmap;
+	struct wl_listener destroy;
+	struct wl_listener request_move;
+	struct wl_listener request_resize;
+	bool mapped;
+	int x, y;
+};
+
+struct tinywl_keyboard {
+	struct wl_list link;
+	struct tinywl_server *server;
+	struct wlr_input_device *device;
+
+	struct wl_listener modifiers;
+	struct wl_listener key;
+};
+
+struct tinywl_pointer {
+	struct wl_list link;
+	struct tinywl_server *server;
+	struct wlr_input_device *device;
+};
+
+static void keyboard_handle_modifiers(
+		struct wl_listener *listener, void *data) {
+	struct tinywl_keyboard *keyboard =
+		wl_container_of(listener, keyboard, modifiers);
+	wlr_seat_set_keyboard(keyboard->server->seat, keyboard->device);
+	wlr_seat_keyboard_notify_modifiers(keyboard->server->seat,
+		&keyboard->device->keyboard->modifiers);
+}
+
+static void keyboard_handle_key(
+		struct wl_listener *listener, void *data) {
+	struct tinywl_keyboard *keyboard =
+		wl_container_of(listener, keyboard, key);
+	struct wlr_event_keyboard_key *event = data;
+	struct wlr_seat *seat = keyboard->server->seat;
+	// TODO: keybindings for moving windows about
+	wlr_seat_set_keyboard(seat, keyboard->device);
+	wlr_seat_keyboard_notify_key(seat, event->time_msec,
+		event->keycode, event->state);
+}
+
+static void server_new_keyboard(struct tinywl_server *server,
+		struct wlr_input_device *device) {
+	struct tinywl_keyboard *keyboard =
+		calloc(1, sizeof(struct tinywl_keyboard));
+	keyboard->server = server;
+	keyboard->device = device;
+
+	struct xkb_rule_names rules = { 0 };
+	struct xkb_context *context = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
+	struct xkb_keymap *keymap = xkb_map_new_from_names(context, &rules,
+		XKB_KEYMAP_COMPILE_NO_FLAGS);
+
+	wlr_keyboard_set_keymap(device->keyboard, keymap);
+	xkb_keymap_unref(keymap);
+	xkb_context_unref(context);
+	wlr_keyboard_set_repeat_info(device->keyboard, 25, 600);
+
+	keyboard->modifiers.notify = keyboard_handle_modifiers;
+	wl_signal_add(&device->keyboard->events.modifiers, &keyboard->modifiers);
+	keyboard->key.notify = keyboard_handle_key;
+	wl_signal_add(&device->keyboard->events.key, &keyboard->key);
+
+	wlr_seat_set_keyboard(server->seat, device);
+
+	wl_list_insert(&server->keyboards, &keyboard->link);
+}
+
+static void server_new_pointer(struct tinywl_server *server,
+		struct wlr_input_device *device) {
+	wlr_cursor_attach_input_device(server->cursor, device);
+}
+
+static void server_new_input(struct wl_listener *listener, void *data) {
+	struct tinywl_server *server =
+		wl_container_of(listener, server, new_input);
+	struct wlr_input_device *device = data;
+	switch (device->type) {
+	case WLR_INPUT_DEVICE_KEYBOARD:
+		server_new_keyboard(server, device);
+		break;
+	case WLR_INPUT_DEVICE_POINTER:
+		server_new_pointer(server, device);
+		break;
+	}
+	uint32_t caps = WL_SEAT_CAPABILITY_POINTER;
+	if (!wl_list_empty(&server->keyboards)) {
+		caps |= WL_SEAT_CAPABILITY_KEYBOARD;
+	}
+	wlr_seat_set_capabilities(server->seat, caps);
+}
+
+static void seat_request_cursor(struct wl_listener *listener, void *data) {
+	struct tinywl_server *server = wl_container_of(
+			listener, server, request_cursor);
+	struct wlr_seat_pointer_request_set_cursor_event *event = data;
+	struct wlr_seat_client *focused_client =
+		server->seat->pointer_state.focused_client;
+	if (focused_client == event->seat_client) {
+		wlr_cursor_set_surface(server->cursor, event->surface,
+				event->hotspot_x, event->hotspot_y);
+	}
+}
+
+static bool view_at(struct tinywl_view *view,
+		double lx, double ly, struct wlr_surface **surface,
+		double *sx, double *sy) {
+	double view_sx = lx - view->x;
+	double view_sy = ly - view->y;
+
+	struct wlr_surface_state *state = &view->xdg_surface->surface->current;
+	struct wlr_box box = {
+		.x = 0, .y = 0,
+		.width = state->width, .height = state->height,
+	};
+
+	double _sx, _sy;
+	struct wlr_surface *_surface = NULL;
+	_surface = wlr_xdg_surface_surface_at(
+			view->xdg_surface, view_sx, view_sy, &_sx, &_sy);
+
+	if (_surface != NULL) {
+		*sx = _sx;
+		*sy = _sy;
+		*surface = _surface;
+		return true;
+	}
+
+	return false;
+}
+
+static struct tinywl_view *desktop_view_at(
+		struct tinywl_server *server, double lx, double ly,
+		struct wlr_surface **surface, double *sx, double *sy) {
+	struct tinywl_view *view;
+	wl_list_for_each(view, &server->views, link) {
+		if (view_at(view, lx, ly, surface, sx, sy)) {
+			return view;
+		}
+	}
+	return NULL;
+}
+
+static void focus_view(struct tinywl_view *view, struct wlr_surface *surface) {
+	struct tinywl_server *server = view->server;
+	struct wlr_seat *seat = server->seat;
+	struct wlr_surface *prev_surface = seat->keyboard_state.focused_surface;
+	if (prev_surface == surface) {
+		return;
+	}
+	if (prev_surface) {
+		struct wlr_xdg_surface *previous = wlr_xdg_surface_from_wlr_surface(
+					seat->keyboard_state.focused_surface);
+		wlr_xdg_toplevel_set_activated(previous, false);
+	}
+	struct wlr_keyboard *keyboard = wlr_seat_get_keyboard(seat);
+	wl_list_remove(&view->link);
+	wl_list_insert(&server->views, &view->link);
+	wlr_xdg_toplevel_set_activated(view->xdg_surface, true);
+	wlr_seat_keyboard_notify_enter(seat, view->xdg_surface->surface,
+		keyboard->keycodes, keyboard->num_keycodes, &keyboard->modifiers);
+}
+
+static void process_cursor_move(struct tinywl_server *server, uint32_t time) {
+	server->grabbed_view->x = server->cursor->x - server->grab_x;
+	server->grabbed_view->y = server->cursor->y - server->grab_y;
+}
+
+static void process_cursor_resize(struct tinywl_server *server, uint32_t time) {
+	struct tinywl_view *view = server->grabbed_view;
+	double dx = server->cursor->x - server->grab_x;
+	double dy = server->cursor->y - server->grab_y;
+	double x = view->x;
+	double y = view->y;
+	int width = server->grab_width;
+	int height = server->grab_height;
+	if (server->resize_edges & WLR_EDGE_TOP) {
+		y = server->grab_y + dy;
+		height -= dy;
+		if (height < 1) {
+			y += height;
+		}
+	} else if (server->resize_edges & WLR_EDGE_BOTTOM) {
+		height += dy;
+	}
+	if (server->resize_edges & WLR_EDGE_LEFT) {
+		x = server->grab_x + dx;
+		width -= dx;
+		if (width < 1) {
+			x += width;
+		}
+	} else if (server->resize_edges & WLR_EDGE_RIGHT) {
+		width += dx;
+	}
+	view->x = x;
+	view->y = y;
+	wlr_xdg_toplevel_set_size(view->xdg_surface, width, height);
+}
+
+static void process_cursor_motion(struct tinywl_server *server, uint32_t time) {
+	if (server->cursor_mode == TINYWL_CURSOR_MOVE) {
+		process_cursor_move(server, time);
+		return;
+	} else if (server->cursor_mode == TINYWL_CURSOR_RESIZE) {
+		process_cursor_resize(server, time);
+		return;
+	}
+
+	double sx, sy;
+	struct wlr_seat *seat = server->seat;
+	struct wlr_surface *surface;
+	struct tinywl_view *view = desktop_view_at(server,
+			server->cursor->x, server->cursor->y, &surface, &sx, &sy);
+	if (!view) {
+		wlr_xcursor_manager_set_cursor_image(
+				server->cursor_mgr, "left_ptr", server->cursor);
+		return;
+	}
+
+	if (surface) {
+		bool focus_changed = seat->pointer_state.focused_surface != surface;
+		wlr_seat_pointer_notify_enter(seat, surface, sx, sy);
+		if (!focus_changed) {
+			wlr_seat_pointer_notify_motion(seat, time, sx, sy);
+		}
+	} else {
+		wlr_seat_pointer_clear_focus(seat);
+	}
+}
+
+static void server_cursor_motion(struct wl_listener *listener, void *data) {
+	struct tinywl_server *server =
+		wl_container_of(listener, server, cursor_motion_absolute);
+	struct wlr_event_pointer_motion *event = data;
+	wlr_cursor_move(server->cursor, event->device,
+			event->delta_x, event->delta_y);
+	process_cursor_motion(server, event->time_msec);
+}
+
+static void server_cursor_motion_absolute(
+		struct wl_listener *listener, void *data) {
+	struct tinywl_server *server =
+		wl_container_of(listener, server, cursor_motion_absolute);
+	struct wlr_event_pointer_motion_absolute *event = data;
+	wlr_cursor_warp_absolute(server->cursor, event->device, event->x, event->y);
+	process_cursor_motion(server, event->time_msec);
+}
+
+static void server_cursor_button(struct wl_listener *listener, void *data) {
+	struct tinywl_server *server =
+		wl_container_of(listener, server, cursor_button);
+	struct wlr_event_pointer_button *event = data;
+	wlr_seat_pointer_notify_button(server->seat,
+			event->time_msec, event->button, event->state);
+	double sx, sy;
+	struct wlr_seat *seat = server->seat;
+	struct wlr_surface *surface;
+	struct tinywl_view *view = desktop_view_at(server,
+			server->cursor->x, server->cursor->y, &surface, &sx, &sy);
+	if (event->state == WLR_BUTTON_RELEASED) {
+		server->cursor_mode = TINYWL_CURSOR_PASSTHROUGH;
+	} else {
+		focus_view(view, surface);
+	}
+}
+
+static void server_cursor_axis(struct wl_listener *listener, void *data) {
+	struct tinywl_server *server =
+		wl_container_of(listener, server, cursor_axis);
+	struct wlr_event_pointer_axis *event = data;
+	wlr_seat_pointer_notify_axis(server->seat,
+			event->time_msec, event->orientation, event->delta,
+			event->delta_discrete, event->source);
+}
+
+struct render_data {
+	struct wlr_output *output;
+	struct wlr_renderer *renderer;
+	struct tinywl_view *view;
+	struct timespec *when;
+};
+
+static void render_surface(struct wlr_surface *surface,
+		int sx, int sy, void *data) {
+	struct render_data *rdata = data;
+	struct tinywl_view *view = rdata->view;
+	struct wlr_output *output = rdata->output;
+
+	struct wlr_texture *texture = wlr_surface_get_texture(surface);
+	if (texture == NULL) {
+		return;
+	}
+
+	double ox, oy;
+	wlr_output_layout_output_coords(
+			view->server->output_layout, output, &ox, &oy);
+	ox += view->x + sx, oy += view->y + sy;
+
+	struct wlr_box box = {
+		.x = ox * output->scale,
+		.y = oy * output->scale,
+		.width = surface->current.width * output->scale,
+		.height = surface->current.height * output->scale,
+	};
+
+	float matrix[9];
+	enum wl_output_transform transform =
+		wlr_output_transform_invert(surface->current.transform);
+	wlr_matrix_project_box(matrix, &box, transform, 0,
+		output->transform_matrix);
+
+	wlr_render_texture_with_matrix(rdata->renderer, texture, matrix, 1);
+
+	wlr_surface_send_frame_done(surface, rdata->when);
+}
+
+static void output_frame(struct wl_listener *listener, void *data) {
+	struct tinywl_output *output =
+		wl_container_of(listener, output, frame);
+	struct wlr_renderer *renderer = output->server->renderer;
+
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	wlr_output_make_current(output->wlr_output, NULL);
+	int width, height;
+	wlr_output_effective_resolution(output->wlr_output, &width, &height);
+	wlr_renderer_begin(renderer, width, height);
+
+	float color[4] = {0.3, 0.3, 0.3, 1.0};
+	wlr_renderer_clear(renderer, color);
+
+	struct tinywl_view *view;
+	wl_list_for_each_reverse(view, &output->server->views, link) {
+		if (!view->mapped) {
+			continue;
+		}
+		struct render_data rdata = {
+			.output = output->wlr_output,
+			.view = view,
+			.renderer = renderer,
+			.when = &now,
+		};
+		wlr_xdg_surface_for_each_surface(view->xdg_surface,
+				render_surface, &rdata);
+	}
+
+	wlr_output_swap_buffers(output->wlr_output, NULL, NULL);
+	wlr_renderer_end(renderer);
+}
+
+static void server_new_output(struct wl_listener *listener, void *data) {
+	struct tinywl_server *server =
+		wl_container_of(listener, server, new_output);
+	struct wlr_output *wlr_output = data;
+
+	struct tinywl_output *output =
+		calloc(1, sizeof(struct tinywl_output));
+	output->wlr_output = wlr_output;
+	output->server = server;
+	output->frame.notify = output_frame;
+	wl_signal_add(&wlr_output->events.frame, &output->frame);
+	wl_list_insert(&server->outputs, &output->link);
+
+	wlr_output_layout_add_auto(server->output_layout, wlr_output);
+
+	wlr_output_create_global(wlr_output);
+}
+
+static void xdg_surface_map(struct wl_listener *listener, void *data) {
+	struct tinywl_view *view = wl_container_of(listener, view, map);
+	view->mapped = true;
+	focus_view(view, view->xdg_surface->surface);
+}
+
+static void xdg_surface_unmap(struct wl_listener *listener, void *data) {
+	struct tinywl_view *view = wl_container_of(listener, view, unmap);
+	view->mapped = false;
+}
+
+static void xdg_surface_destroy(struct wl_listener *listener, void *data) {
+	struct tinywl_view *view = wl_container_of(listener, view, destroy);
+	wl_list_remove(&view->link);
+	free(view);
+}
+
+static void begin_interactive(struct tinywl_view *view,
+		enum tinywl_cursor_mode mode, uint32_t edges) {
+	struct tinywl_server *server = view->server;
+	struct wlr_surface *focused_surface =
+		server->seat->pointer_state.focused_surface;
+	if (view->xdg_surface->surface != focused_surface) {
+		return;
+	}
+	server->grabbed_view = view;
+	server->cursor_mode = mode;
+	struct wlr_box geo_box;
+	wlr_xdg_surface_get_geometry(view->xdg_surface, &geo_box);
+	if (mode == TINYWL_CURSOR_MOVE) {
+		server->grab_x = server->cursor->x - view->x;
+		server->grab_y = server->cursor->y - view->y;
+	} else {
+		server->grab_x = server->cursor->x + geo_box.x;
+		server->grab_y = server->cursor->y + geo_box.y;
+	}
+	server->grab_width = geo_box.width;
+	server->grab_height = geo_box.height;
+	server->resize_edges = edges;
+}
+
+static void xdg_toplevel_request_move(
+		struct wl_listener *listener, void *data) {
+	struct tinywl_view *view = wl_container_of(listener, view, request_move);
+	begin_interactive(view, TINYWL_CURSOR_MOVE, 0);
+}
+
+static void xdg_toplevel_request_resize(
+		struct wl_listener *listener, void *data) {
+	struct wlr_xdg_toplevel_resize_event *event = data;
+	struct tinywl_view *view = wl_container_of(listener, view, request_resize);
+	begin_interactive(view, TINYWL_CURSOR_RESIZE, event->edges);
+}
+
+static void server_new_xdg_surface(struct wl_listener *listener, void *data) {
+	struct tinywl_server *server =
+		wl_container_of(listener, server, new_xdg_surface);
+	struct wlr_xdg_surface *xdg_surface = data;
+	if (xdg_surface->role != WLR_XDG_SURFACE_ROLE_TOPLEVEL) {
+		return;
+	}
+
+	struct tinywl_view *view =
+		calloc(1, sizeof(struct tinywl_view));
+	view->server = server;
+	view->xdg_surface = xdg_surface;
+
+	view->map.notify = xdg_surface_map;
+	wl_signal_add(&xdg_surface->events.map, &view->map);
+	view->unmap.notify = xdg_surface_unmap;
+	wl_signal_add(&xdg_surface->events.unmap, &view->unmap);
+	view->destroy.notify = xdg_surface_destroy;
+	wl_signal_add(&xdg_surface->events.destroy, &view->destroy);
+
+	struct wlr_xdg_toplevel *toplevel = xdg_surface->toplevel;
+	view->request_move.notify = xdg_toplevel_request_move;
+	wl_signal_add(&toplevel->events.request_move, &view->request_move);
+	view->request_resize.notify = xdg_toplevel_request_resize;
+	wl_signal_add(&toplevel->events.request_resize, &view->request_resize);
+
+	wl_list_insert(&server->views, &view->link);
+}
+
+int main(int argc, char *argv[]) {
+	char *startup_cmd = NULL;
+
+	int c;
+	while ((c = getopt(argc, argv, "s:h")) != -1) {
+		switch (c) {
+		case 's':
+			startup_cmd = optarg;
+			break;
+		default:
+			printf("Usage: %s [-s startup command]\n", argv[0]);
+			return 0;
+		}
+	}
+	if (optind < argc) {
+		printf("Usage: %s [-s startup command]\n", argv[0]);
+		return 0;
+	}
+
+	struct tinywl_server server;
+	server.wl_display = wl_display_create();
+	server.backend = wlr_backend_autocreate(server.wl_display, NULL);
+
+	server.renderer = wlr_backend_get_renderer(server.backend);
+	wlr_renderer_init_wl_display(server.renderer, server.wl_display);
+
+	wlr_compositor_create(server.wl_display, server.renderer);
+	wlr_linux_dmabuf_v1_create(server.wl_display, server.renderer);
+	wlr_data_device_manager_create(server.wl_display);
+
+	server.output_layout = wlr_output_layout_create();
+
+	wl_list_init(&server.outputs);
+	server.new_output.notify = server_new_output;
+	wl_signal_add(&server.backend->events.new_output, &server.new_output);
+
+	wl_list_init(&server.views);
+	server.xdg_shell = wlr_xdg_shell_create(server.wl_display);
+	server.new_xdg_surface.notify = server_new_xdg_surface;
+	wl_signal_add(&server.xdg_shell->events.new_surface,
+			&server.new_xdg_surface);
+
+	server.cursor = wlr_cursor_create();
+	wlr_cursor_attach_output_layout(server.cursor, server.output_layout);
+
+	server.cursor_mgr = wlr_xcursor_manager_create(NULL, 24);
+	wlr_xcursor_manager_load(server.cursor_mgr, 1);
+
+	server.cursor_motion.notify = server_cursor_motion;
+	wl_signal_add(&server.cursor->events.motion, &server.cursor_motion);
+	server.cursor_motion_absolute.notify = server_cursor_motion_absolute;
+	wl_signal_add(&server.cursor->events.motion_absolute,
+			&server.cursor_motion_absolute);
+	server.cursor_button.notify = server_cursor_button;
+	wl_signal_add(&server.cursor->events.button, &server.cursor_button);
+	server.cursor_axis.notify = server_cursor_axis;
+	wl_signal_add(&server.cursor->events.axis, &server.cursor_axis);
+
+	wl_list_init(&server.keyboards);
+	server.new_input.notify = server_new_input;
+	wl_signal_add(&server.backend->events.new_input, &server.new_input);
+	server.seat = wlr_seat_create(server.wl_display, "seat0");
+	server.request_cursor.notify = seat_request_cursor;
+	wl_signal_add(&server.seat->events.request_set_cursor,
+			&server.request_cursor);
+
+	const char *socket = wl_display_add_socket_auto(server.wl_display);
+	if (!socket) {
+		wlr_backend_destroy(server.backend);
+		return 1;
+	}
+
+	if (!wlr_backend_start(server.backend)) {
+		wlr_backend_destroy(server.backend);
+		wl_display_destroy(server.wl_display);
+		return 1;
+	}
+
+	setenv("WAYLAND_DISPLAY", socket, true);
+	if (startup_cmd) {
+		if (fork() == 0) {
+			execl("/bin/sh", "/bin/sh", "-c", startup_cmd, (void *)NULL);
+		}
+	}
+	wl_display_run(server.wl_display);
+
+	wl_display_destroy_clients(server.wl_display);
+	wl_display_destroy(server.wl_display);
+	return 0;
+}