examples/scene-graph: new example

examples/meson.build

@@ -51,6 +51,10 @@ compositors = {
 	'quads': {
 		'src': 'quads.c',
 	},
+	'scene-graph': {
+		'src': 'scene-graph.c',
+		'proto': ['xdg-shell'],
+	},
 }
 
 clients = {

examples/scene-graph.c

@@ -0,0 +1,199 @@
+#define _POSIX_C_SOURCE 200112L
+#include <assert.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <wayland-server-core.h>
+#include <wlr/backend.h>
+#include <wlr/render/wlr_renderer.h>
+#include <wlr/types/wlr_compositor.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_scene.h>
+#include <wlr/types/wlr_surface.h>
+#include <wlr/types/wlr_xdg_shell.h>
+#include <wlr/util/log.h>
+
+/* Simple compositor making use of the scene-graph API. Input is unimplemented.
+ *
+ * New surfaces are stacked on top of the existing ones as they appear. */
+
+struct server {
+	struct wl_display *display;
+	struct wlr_backend *backend;
+	struct wlr_scene *scene;
+
+	struct wl_list outputs;
+	struct wl_list surfaces;
+
+	struct wl_listener new_output;
+	struct wl_listener new_surface;
+};
+
+struct surface {
+	struct wlr_surface *wlr;
+	struct wlr_scene_surface *scene_surface;
+	struct wl_list link;
+
+	struct wl_listener destroy;
+};
+
+struct output {
+	struct wl_list link;
+	struct server *server;
+	struct wlr_output *wlr;
+
+	struct wl_listener frame;
+};
+
+static void output_handle_frame(struct wl_listener *listener, void *data) {
+	struct output *output = wl_container_of(listener, output, frame);
+
+	if (!wlr_output_attach_render(output->wlr, NULL)) {
+		return;
+	}
+
+	struct wlr_renderer *renderer = wlr_backend_get_renderer(output->wlr->backend);
+	assert(renderer != NULL);
+
+	int width, height;
+	wlr_output_effective_resolution(output->wlr, &width, &height);
+	wlr_renderer_begin(renderer, width, height);
+	wlr_renderer_clear(renderer, (float[4]){ 0.3, 0.3, 0.3, 1.0 });
+
+	wlr_scene_render_output(output->server->scene, output->wlr, 0, 0, NULL);
+	wlr_output_render_software_cursors(output->wlr, NULL);
+
+	wlr_renderer_end(renderer);
+
+	if (!wlr_output_commit(output->wlr)) {
+		return;
+	}
+
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	struct surface *surface;
+	wl_list_for_each(surface, &output->server->surfaces, link) {
+		wlr_surface_send_frame_done(surface->wlr, &now);
+	}
+}
+
+static void server_handle_new_output(struct wl_listener *listener, void *data) {
+	struct server *server = wl_container_of(listener, server, new_output);
+	struct wlr_output *wlr_output = data;
+
+	struct output *output =
+		calloc(1, sizeof(struct output));
+	output->wlr = wlr_output;
+	output->server = server;
+	output->frame.notify = output_handle_frame;
+	wl_signal_add(&wlr_output->events.frame, &output->frame);
+	wl_list_insert(&server->outputs, &output->link);
+
+	if (!wl_list_empty(&wlr_output->modes)) {
+		struct wlr_output_mode *mode = wlr_output_preferred_mode(wlr_output);
+		wlr_output_set_mode(wlr_output, mode);
+		wlr_output_commit(wlr_output);
+	}
+
+	wlr_output_create_global(wlr_output);
+}
+
+static void surface_handle_destroy(struct wl_listener *listener, void *data) {
+	struct surface *surface = wl_container_of(listener, surface, destroy);
+	wlr_scene_node_destroy(&surface->scene_surface->node);
+	wl_list_remove(&surface->destroy.link);
+	wl_list_remove(&surface->link);
+	free(surface);
+}
+
+static void server_handle_new_surface(struct wl_listener *listener,
+		void *data) {
+	struct server *server = wl_container_of(listener, server, new_surface);
+	struct wlr_surface *wlr_surface = data;
+
+	int pos = 50 * wl_list_length(&server->surfaces);
+
+	struct surface *surface = calloc(1, sizeof(struct surface));
+	surface->wlr = wlr_surface;
+	surface->destroy.notify = surface_handle_destroy;
+	wl_signal_add(&wlr_surface->events.destroy, &surface->destroy);
+	surface->scene_surface =
+		wlr_scene_surface_create(&server->scene->node, wlr_surface);
+	wl_list_insert(server->surfaces.prev, &surface->link);
+
+	wlr_scene_node_set_position(&surface->scene_surface->node, pos, pos);
+}
+
+int main(int argc, char *argv[]) {
+	wlr_log_init(WLR_DEBUG, NULL);
+
+	char *startup_cmd = NULL;
+
+	int c;
+	while ((c = getopt(argc, argv, "s:")) != -1) {
+		switch (c) {
+		case 's':
+			startup_cmd = optarg;
+			break;
+		default:
+			printf("usage: %s [-s startup-command]\n", argv[0]);
+			return EXIT_FAILURE;
+		}
+	}
+	if (optind < argc) {
+		printf("usage: %s [-s startup-command]\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	struct server server = {0};
+	server.display = wl_display_create();
+	server.backend = wlr_backend_autocreate(server.display);
+	server.scene = wlr_scene_create();
+
+	struct wlr_renderer *renderer = wlr_backend_get_renderer(server.backend);
+	wlr_renderer_init_wl_display(renderer, server.display);
+
+	struct wlr_compositor *compositor =
+		wlr_compositor_create(server.display, renderer);
+
+	wlr_xdg_shell_create(server.display);
+
+	wl_list_init(&server.outputs);
+	wl_list_init(&server.surfaces);
+
+	server.new_output.notify = server_handle_new_output;
+	wl_signal_add(&server.backend->events.new_output, &server.new_output);
+
+	server.new_surface.notify = server_handle_new_surface;
+	wl_signal_add(&compositor->events.new_surface, &server.new_surface);
+
+	const char *socket = wl_display_add_socket_auto(server.display);
+	if (!socket) {
+		wl_display_destroy(server.display);
+		return EXIT_FAILURE;
+	}
+
+	if (!wlr_backend_start(server.backend)) {
+		wl_display_destroy(server.display);
+		return EXIT_FAILURE;
+	}
+
+	setenv("WAYLAND_DISPLAY", socket, true);
+	if (startup_cmd != NULL) {
+		if (fork() == 0) {
+			execl("/bin/sh", "/bin/sh", "-c", startup_cmd, (void *)NULL);
+		}
+	}
+
+	wlr_log(WLR_INFO, "Running Wayland compositor on WAYLAND_DISPLAY=%s",
+		socket);
+	wl_display_run(server.display);
+
+	wl_display_destroy_clients(server.display);
+	wl_display_destroy(server.display);
+	return EXIT_SUCCESS;
+}