examples/output-layers: new example

2 files changed, 298 insertions, 0 deletions

diff --git a/examples/meson.build b/examples/meson.build
index 51e7d311..33216bdb 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -57,6 +57,12 @@ compositors = {
 		'src': 'scene-graph.c',
 		'proto': ['xdg-shell'],
 	},
+	'output-layers': {
+		'src': 'output-layers.c',
+		'proto': [
+			'xdg-shell',
+		],
+	},
 }
 
 clients = {
diff --git a/examples/output-layers.c b/examples/output-layers.c
new file mode 100644
index 00000000..bc03ea66
--- /dev/null
+++ b/examples/output-layers.c
@@ -0,0 +1,292 @@
+#define _POSIX_C_SOURCE 200112L
+#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/allocator.h>
+#include <wlr/render/wlr_renderer.h>
+#include <wlr/types/wlr_compositor.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_output_layer.h>
+#include <wlr/types/wlr_xdg_shell.h>
+#include <wlr/util/log.h>
+
+/* Simple compositor making use of the output layers API. The compositor will
+ * attempt to display client surfaces with output layers. Input is
+ * unimplemented.
+ *
+ * New surfaces are stacked on top of the existing ones as they appear.
+ * Surfaces that don't make it into an output layer are rendered as usual. */
+
+struct server {
+	struct wl_display *wl_display;
+	struct wlr_backend *backend;
+	struct wlr_renderer *renderer;
+	struct wlr_allocator *allocator;
+
+	struct wl_list outputs;
+
+	struct wl_listener new_output;
+	struct wl_listener new_surface;
+};
+
+struct output_surface {
+	struct wlr_surface *wlr_surface;
+	struct wlr_output_layer *layer;
+	struct wl_list link;
+
+	int x, y;
+	struct wlr_buffer *buffer;
+
+	bool first_commit, layer_accepted, prev_layer_accepted;
+
+	struct wl_listener destroy;
+	struct wl_listener commit;
+};
+
+struct output {
+	struct wl_list link;
+	struct server *server;
+	struct wlr_output *wlr_output;
+	struct wl_list surfaces;
+
+	struct wl_listener frame;
+};
+
+static void output_handle_frame(struct wl_listener *listener, void *data) {
+	struct output *output = wl_container_of(listener, output, frame);
+	struct wlr_renderer *renderer = output->server->renderer;
+
+	struct wl_array layers_arr = {0};
+	struct output_surface *output_surface;
+	wl_list_for_each(output_surface, &output->surfaces, link) {
+		struct wlr_output_layer_state *layer_state =
+			wl_array_add(&layers_arr, sizeof(*layer_state));
+		*layer_state = (struct wlr_output_layer_state){
+			.layer = output_surface->layer,
+			.buffer = output_surface->buffer,
+			.x = output_surface->x,
+			.y = output_surface->y,
+		};
+	}
+
+	wlr_output_set_layers(output->wlr_output, layers_arr.data,
+		layers_arr.size / sizeof(struct wlr_output_layer_state));
+
+	if (!wlr_output_test(output->wlr_output)) {
+		wlr_log(WLR_ERROR, "wlr_output_test() failed");
+		return;
+	}
+
+	if (!wlr_output_attach_render(output->wlr_output, NULL)) {
+		wlr_log(WLR_ERROR, "wlr_output_attach_render() failed");
+		return;
+	}
+
+	int width, height;
+	wlr_output_effective_resolution(output->wlr_output, &width, &height);
+	wlr_renderer_begin(renderer, width, height);
+	wlr_renderer_clear(renderer, (float[4]){ 0.3, 0.3, 0.3, 1.0 });
+
+	size_t i = 0;
+	struct wlr_output_layer_state *layers = layers_arr.data;
+	wl_list_for_each(output_surface, &output->surfaces, link) {
+		struct wlr_surface *wlr_surface = output_surface->wlr_surface;
+
+		output_surface->layer_accepted = layers[i].accepted;
+		i++;
+
+		if (wlr_surface->buffer == NULL || output_surface->layer_accepted) {
+			continue;
+		}
+
+		struct wlr_texture *texture = wlr_surface_get_texture(wlr_surface);
+		if (texture == NULL) {
+			continue;
+		}
+
+		wlr_render_texture(renderer, texture, output->wlr_output->transform_matrix,
+			output_surface->x, output_surface->y, 1.0);
+	}
+
+	wlr_renderer_end(renderer);
+
+	wlr_output_commit(output->wlr_output);
+
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	wl_list_for_each(output_surface, &output->surfaces, link) {
+		wlr_surface_send_frame_done(output_surface->wlr_surface, &now);
+
+		if (output_surface->wlr_surface->buffer == NULL) {
+			continue;
+		}
+
+		if ((output_surface->first_commit ||
+				!output_surface->prev_layer_accepted) &&
+				output_surface->layer_accepted) {
+			wlr_log(WLR_INFO, "Scanning out wlr_surface %p on output '%s'",
+				output_surface->wlr_surface, output->wlr_output->name);
+		}
+		if ((output_surface->first_commit ||
+				output_surface->prev_layer_accepted) &&
+				!output_surface->layer_accepted) {
+			wlr_log(WLR_INFO, "Cannot scan out wlr_surface %p on output '%s'",
+				output_surface->wlr_surface, output->wlr_output->name);
+		}
+		output_surface->prev_layer_accepted = output_surface->layer_accepted;
+		output_surface->first_commit = false;
+	}
+
+	wl_array_release(&layers_arr);
+}
+
+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;
+
+	wlr_output_init_render(wlr_output, server->allocator, server->renderer);
+
+	struct output *output = calloc(1, sizeof(*output));
+	output->wlr_output = wlr_output;
+	output->server = server;
+	wl_list_init(&output->surfaces);
+	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 output_surface_handle_destroy(struct wl_listener *listener,
+		void *data) {
+	struct output_surface *output_surface =
+		wl_container_of(listener, output_surface, destroy);
+	wlr_buffer_unlock(output_surface->buffer);
+	wlr_output_layer_destroy(output_surface->layer);
+	wl_list_remove(&output_surface->destroy.link);
+	wl_list_remove(&output_surface->commit.link);
+	wl_list_remove(&output_surface->link);
+	free(output_surface);
+}
+
+static void output_surface_handle_commit(struct wl_listener *listener,
+		void *data) {
+	struct output_surface *output_surface =
+		wl_container_of(listener, output_surface, commit);
+
+	struct wlr_buffer *buffer = NULL;
+	if (output_surface->wlr_surface->buffer != NULL) {
+		buffer = wlr_buffer_lock(&output_surface->wlr_surface->buffer->base);
+	}
+
+	wlr_buffer_unlock(output_surface->buffer);
+	output_surface->buffer = buffer;
+}
+
+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;
+
+	struct output *output;
+	wl_list_for_each(output, &server->outputs, link) {
+		struct output_surface *output_surface = calloc(1, sizeof(*output_surface));
+		output_surface->wlr_surface = wlr_surface;
+		output_surface->destroy.notify = output_surface_handle_destroy;
+		wl_signal_add(&wlr_surface->events.destroy, &output_surface->destroy);
+		output_surface->commit.notify = output_surface_handle_commit;
+		wl_signal_add(&wlr_surface->events.commit, &output_surface->commit);
+
+		output_surface->layer = wlr_output_layer_create(output->wlr_output);
+
+		int pos = 50 * wl_list_length(&output->surfaces);
+
+		output_surface->x = output_surface->y = pos;
+		output_surface->first_commit = true;
+
+		wl_list_insert(output->surfaces.prev, &output_surface->link);
+	}
+}
+
+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.wl_display = wl_display_create();
+	server.backend = wlr_backend_autocreate(server.wl_display, NULL);
+
+	server.renderer = wlr_renderer_autocreate(server.backend);
+	wlr_renderer_init_wl_display(server.renderer, server.wl_display);
+
+	server.allocator = wlr_allocator_autocreate(server.backend,
+		server.renderer);
+
+	struct wlr_compositor *compositor =
+		wlr_compositor_create(server.wl_display, server.renderer);
+
+	wlr_xdg_shell_create(server.wl_display, 1);
+
+	wl_list_init(&server.outputs);
+
+	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.wl_display);
+	if (!socket) {
+		wl_display_destroy(server.wl_display);
+		return EXIT_FAILURE;
+	}
+
+	if (!wlr_backend_start(server.backend)) {
+		wl_display_destroy(server.wl_display);
+		return EXIT_FAILURE;
+	}
+
+	setenv("WAYLAND_DISPLAY", socket, true);
+	if (startup_cmd != NULL) {
+		if (fork() == 0) {
+			execlp("sh", "sh", "-c", startup_cmd, (char *)NULL);
+		}
+	}
+
+	wlr_log(WLR_INFO, "Running Wayland compositor on WAYLAND_DISPLAY=%s",
+		socket);
+	wl_display_run(server.wl_display);
+
+	wl_display_destroy_clients(server.wl_display);
+	wl_display_destroy(server.wl_display);
+	return EXIT_SUCCESS;
+}