Merge branch 'wl-multi-output-touch' into 'master'

backend/wayland: implement multi-output touch

Closes #4102

See merge request wlroots/wlroots!5399

backend/wayland/backend.c

@@ -457,10 +457,6 @@ static bool backend_start(struct wlr_backend *backend) {
 			init_seat_keyboard(seat);
 		}
 
-		if (seat->wl_touch) {
-			init_seat_touch(seat);
-		}
-
 		if (wl->tablet_manager) {
 			init_seat_tablet(seat);
 		}

backend/wayland/output.c

@@ -1151,6 +1151,9 @@ static void output_start(struct wlr_wl_output *output) {
 		if (seat->wl_pointer) {
 			create_pointer(seat, output);
 		}
+		if (seat->wl_touch) {
+			create_touch(seat, output);
+		}
 	}
 }
 

backend/wayland/seat.c

@@ -110,42 +110,73 @@ void init_seat_keyboard(struct wlr_wl_seat *seat) {
 		&seat->wlr_keyboard.base);
 }
 
-static void touch_coordinates_to_absolute(struct wlr_wl_seat *seat,
-		wl_fixed_t x, wl_fixed_t y, double *sx, double *sy) {
-	/**
-	 * TODO: multi-output touch support
-	 * Although the wayland backend supports multi-output pointers, the support
-	 * for multi-output touch has been left on the side for simplicity reasons.
-	 * If this is a feature you want/need, please open an issue on the wlroots
-	 * tracker here https://gitlab.freedesktop.org/wlroots/wlroots/-/issues
-	 */
-	struct wlr_wl_output *output, *tmp;
-	wl_list_for_each_safe(output, tmp, &seat->backend->outputs, link) {
-		*sx = wl_fixed_to_double(x) / output->wlr_output.width;
-		*sy = wl_fixed_to_double(y) / output->wlr_output.height;
-		return; // Choose the first output in the list
+static struct wlr_wl_touch *touch_for_output(struct wlr_wl_seat *seat,
+		struct wlr_wl_output *output) {
+	struct wlr_wl_touch *touch;
+	wl_list_for_each(touch, &seat->touches, link) {
+		if (touch->output == output) {
+			return touch;
+		}
 	}
+	return NULL;
+}
 
-	*sx = *sy = 0;
+static struct wlr_wl_touch *touch_for_id(struct wlr_wl_seat *seat,
+		int32_t id) {
+	struct wlr_wl_touch_points *points = &seat->touch_points;
+	for (size_t i = 0; i < points->len; i++) {
+		if (points->ids[i] == id) {
+			return points->touches[i];
+		}
+	}
+	return NULL;
+}
+
+static void touch_coordinates_to_absolute(struct wlr_wl_touch *touch,
+		wl_fixed_t x, wl_fixed_t y, double *sx, double *sy) {
+	struct wlr_output *output = &touch->output->wlr_output;
+	if (output->width <= 0 || output->height <= 0) {
+		*sx = *sy = 0;
+		return;
+	}
+	*sx = wl_fixed_to_double(x) / output->width;
+	*sy = wl_fixed_to_double(y) / output->height;
 }
 
 static void touch_handle_down(void *data, struct wl_touch *wl_touch,
 		uint32_t serial, uint32_t time, struct wl_surface *surface,
 		int32_t id, wl_fixed_t x, wl_fixed_t y) {
 	struct wlr_wl_seat *seat = data;
-	struct wlr_touch *touch = &seat->wlr_touch;
+
+	if (surface == NULL) {
+		return;
+	}
+
+	struct wlr_wl_output *output =
+		get_wl_output_from_surface(seat->backend, surface);
+	if (output == NULL) {
+		return;
+	}
+
+	struct wlr_wl_touch *touch = touch_for_output(seat, output);
+	if (touch == NULL) {
+		return;
+	}
 
 	struct wlr_wl_touch_points *points = &seat->touch_points;
 	assert(points->len != sizeof(points->ids) / sizeof(points->ids[0]));
+	points->touches[points->len] = touch;
 	points->ids[points->len++] = id;
 
+	touch->needs_frame = true;
+
 	struct wlr_touch_down_event event = {
-		.touch = touch,
+		.touch = &touch->wlr_touch,
 		.time_msec = time,
 		.touch_id = id,
 	};
-	touch_coordinates_to_absolute(seat, x, y, &event.x, &event.y);
-	wl_signal_emit_mutable(&touch->events.down, &event);
+	touch_coordinates_to_absolute(touch, x, y, &event.x, &event.y);
+	wl_signal_emit_mutable(&touch->wlr_touch.events.down, &event);
 }
 
 static bool remove_touch_point(struct wlr_wl_touch_points *points, int32_t id) {
@@ -154,6 +185,8 @@ static bool remove_touch_point(struct wlr_wl_touch_points *points, int32_t id) {
 		if (points->ids[i] == id) {
 			size_t remaining = points->len - i - 1;
 			memmove(&points->ids[i], &points->ids[i + 1], remaining * sizeof(id));
+			memmove(&points->touches[i], &points->touches[i + 1],
+				remaining * sizeof(points->touches[0]));
 			points->len--;
 			return true;
 		}
@@ -164,52 +197,70 @@ static bool remove_touch_point(struct wlr_wl_touch_points *points, int32_t id) {
 static void touch_handle_up(void *data, struct wl_touch *wl_touch,
 		uint32_t serial, uint32_t time, int32_t id) {
 	struct wlr_wl_seat *seat = data;
-	struct wlr_touch *touch = &seat->wlr_touch;
 
+	struct wlr_wl_touch *touch = touch_for_id(seat, id);
 	remove_touch_point(&seat->touch_points, id);
+	if (touch == NULL) {
+		return;
+	}
+
+	touch->needs_frame = true;
 
 	struct wlr_touch_up_event event = {
-		.touch = touch,
+		.touch = &touch->wlr_touch,
 		.time_msec = time,
 		.touch_id = id,
 	};
-	wl_signal_emit_mutable(&touch->events.up, &event);
+	wl_signal_emit_mutable(&touch->wlr_touch.events.up, &event);
 }
 
 static void touch_handle_motion(void *data, struct wl_touch *wl_touch,
 		uint32_t time, int32_t id, wl_fixed_t x, wl_fixed_t y) {
 	struct wlr_wl_seat *seat = data;
-	struct wlr_touch *touch = &seat->wlr_touch;
+
+	struct wlr_wl_touch *touch = touch_for_id(seat, id);
+	if (touch == NULL) {
+		return;
+	}
+
+	touch->needs_frame = true;
 
 	struct wlr_touch_motion_event event = {
-		.touch = touch,
+		.touch = &touch->wlr_touch,
 		.time_msec = time,
 		.touch_id = id,
 	};
-
-	touch_coordinates_to_absolute(seat, x, y, &event.x, &event.y);
-	wl_signal_emit_mutable(&touch->events.motion, &event);
+	touch_coordinates_to_absolute(touch, x, y, &event.x, &event.y);
+	wl_signal_emit_mutable(&touch->wlr_touch.events.motion, &event);
 }
 
 static void touch_handle_frame(void *data, struct wl_touch *wl_touch) {
 	struct wlr_wl_seat *seat = data;
-	wl_signal_emit_mutable(&seat->wlr_touch.events.frame, NULL);
+
+	struct wlr_wl_touch *touch;
+	wl_list_for_each(touch, &seat->touches, link) {
+		if (touch->needs_frame) {
+			touch->needs_frame = false;
+			wl_signal_emit_mutable(&touch->wlr_touch.events.frame, NULL);
+		}
+	}
 }
 
 static void touch_handle_cancel(void *data, struct wl_touch *wl_touch) {
 	struct wlr_wl_seat *seat = data;
-	struct wlr_touch *touch = &seat->wlr_touch;
 
 	// wayland's cancel event applies to all active touch points
-	for (size_t i = 0; i < seat->touch_points.len; i++) {
+	struct wlr_wl_touch_points *points = &seat->touch_points;
+	for (size_t i = 0; i < points->len; i++) {
+		struct wlr_wl_touch *touch = points->touches[i];
 		struct wlr_touch_cancel_event event = {
-			.touch = touch,
+			.touch = &touch->wlr_touch,
 			.time_msec = 0,
-			.touch_id = seat->touch_points.ids[i],
+			.touch_id = points->ids[i],
 		};
-		wl_signal_emit_mutable(&touch->events.cancel, &event);
+		wl_signal_emit_mutable(&touch->wlr_touch.events.cancel, &event);
 	}
-	seat->touch_points.len = 0;
+	points->len = 0;
 }
 
 static void touch_handle_shape(void *data, struct wl_touch *wl_touch,
@@ -236,24 +287,91 @@ static const struct wlr_touch_impl touch_impl = {
 	.name = "wl-touch",
 };
 
-void init_seat_touch(struct wlr_wl_seat *seat) {
+static void destroy_touch(struct wlr_wl_touch *touch) {
+	struct wlr_wl_seat *seat = touch->seat;
+
+	// Forget any active touch points held by this device
+	struct wlr_wl_touch_points *points = &seat->touch_points;
+	for (size_t i = points->len; i-- > 0;) {
+		if (points->touches[i] == touch) {
+			remove_touch_point(points, points->ids[i]);
+		}
+	}
+
+	wlr_touch_finish(&touch->wlr_touch);
+	wl_list_remove(&touch->output_destroy.link);
+	wl_list_remove(&touch->link);
+	free(touch);
+}
+
+static void touch_output_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_wl_touch *touch =
+		wl_container_of(listener, touch, output_destroy);
+	destroy_touch(touch);
+}
+
+void create_touch(struct wlr_wl_seat *seat, struct wlr_wl_output *output) {
 	assert(seat->wl_touch);
 
+	if (touch_for_output(seat, output)) {
+		wlr_log(WLR_DEBUG,
+			"touch for output '%s' from seat '%s' already exists",
+			output->wlr_output.name, seat->name);
+		return;
+	}
+
+	wlr_log(WLR_DEBUG, "creating touch for output '%s' from seat '%s'",
+		output->wlr_output.name, seat->name);
+
+	struct wlr_wl_touch *touch = calloc(1, sizeof(*touch));
+	if (touch == NULL) {
+		wlr_log(WLR_ERROR, "failed to allocate wlr_wl_touch");
+		return;
+	}
+
 	char name[128] = {0};
 	snprintf(name, sizeof(name), "wayland-touch-%s", seat->name);
+	wlr_touch_init(&touch->wlr_touch, &touch_impl, name);
 
-	wlr_touch_init(&seat->wlr_touch, &touch_impl, name);
+	touch->wlr_touch.output_name = strdup(output->wlr_output.name);
+
+	touch->seat = seat;
+	touch->output = output;
+
+	wl_signal_add(&output->wlr_output.events.destroy, &touch->output_destroy);
+	touch->output_destroy.notify = touch_output_destroy;
+
+	wl_signal_emit_mutable(&seat->backend->backend.events.new_input,
+		&touch->wlr_touch.base);
+
+	wl_list_insert(&seat->touches, &touch->link);
+}
+
+void init_seat_touch(struct wlr_wl_seat *seat) {
+	assert(seat->wl_touch);
+
+	wl_list_init(&seat->touches);
 
 	struct wlr_wl_output *output;
 	wl_list_for_each(output, &seat->backend->outputs, link) {
-		/* Multi-output touch not supported */
-		seat->wlr_touch.output_name = strdup(output->wlr_output.name);
-		break;
+		create_touch(seat, output);
 	}
 
 	wl_touch_add_listener(seat->wl_touch, &touch_listener, seat);
-	wl_signal_emit_mutable(&seat->backend->backend.events.new_input,
-		&seat->wlr_touch.base);
+}
+
+void finish_seat_touch(struct wlr_wl_seat *seat) {
+	assert(seat->wl_touch);
+
+	wl_touch_release(seat->wl_touch);
+
+	struct wlr_wl_touch *touch, *tmp;
+	wl_list_for_each_safe(touch, tmp, &seat->touches, link) {
+		destroy_touch(touch);
+	}
+
+	seat->touch_points.len = 0;
+	seat->wl_touch = NULL;
 }
 
 static const struct wl_seat_listener seat_listener;
@@ -275,8 +393,7 @@ bool create_wl_seat(struct wl_seat *wl_seat, struct wlr_wl_backend *wl,
 
 void destroy_wl_seat(struct wlr_wl_seat *seat) {
 	if (seat->wl_touch) {
-		wl_touch_release(seat->wl_touch);
-		wlr_touch_finish(&seat->wlr_touch);
+		finish_seat_touch(seat);
 	}
 	if (seat->wl_pointer) {
 		finish_seat_pointer(seat);
@@ -356,16 +473,11 @@ static void seat_handle_capabilities(void *data, struct wl_seat *wl_seat,
 		wlr_log(WLR_DEBUG, "seat '%s' offering touch", seat->name);
 
 		seat->wl_touch = wl_seat_get_touch(wl_seat);
-		if (backend->started) {
-			init_seat_touch(seat);
-		}
+		init_seat_touch(seat);
 	}
 	if (!(caps & WL_SEAT_CAPABILITY_TOUCH) && seat->wl_touch != NULL) {
 		wlr_log(WLR_DEBUG, "seat '%s' dropping touch", seat->name);
-
-		wl_touch_release(seat->wl_touch);
-		wlr_touch_finish(&seat->wlr_touch);
-		seat->wl_touch = NULL;
+		finish_seat_touch(seat);
 	}
 }
 

include/backend/wayland.h

@@ -149,8 +149,21 @@ struct wlr_wl_pointer {
 	struct wl_list link;
 };
 
+struct wlr_wl_touch {
+	struct wlr_touch wlr_touch;
+
+	struct wlr_wl_seat *seat;
+	struct wlr_wl_output *output;
+	bool needs_frame;
+
+	struct wl_listener output_destroy;
+
+	struct wl_list link;
+};
+
 struct wlr_wl_touch_points {
 	int32_t ids[64];
+	struct wlr_wl_touch *touches[64];
 	size_t len;
 };
 
@@ -174,7 +187,7 @@ struct wlr_wl_seat {
 	struct zwp_relative_pointer_v1 *relative_pointer;
 
 	struct wl_touch *wl_touch;
-	struct wlr_touch wlr_touch;
+	struct wl_list touches;
 	struct wlr_wl_touch_points touch_points;
 
 	struct zwp_tablet_seat_v2 *zwp_tablet_seat_v2;
@@ -200,6 +213,8 @@ void finish_seat_pointer(struct wlr_wl_seat *seat);
 void create_pointer(struct wlr_wl_seat *seat, struct wlr_wl_output *output);
 
 void init_seat_touch(struct wlr_wl_seat *seat);
+void finish_seat_touch(struct wlr_wl_seat *seat);
+void create_touch(struct wlr_wl_seat *seat, struct wlr_wl_output *output);
 
 void init_seat_tablet(struct wlr_wl_seat *seat);
 void finish_seat_tablet(struct wlr_wl_seat *seat);