screencopy: Implement damage reporting

2 files changed, 208 insertions, 28 deletions

diff --git a/include/wlr/types/wlr_screencopy_v1.h b/include/wlr/types/wlr_screencopy_v1.h
index ab81f81a..b42ec3a8 100644
--- a/include/wlr/types/wlr_screencopy_v1.h
+++ b/include/wlr/types/wlr_screencopy_v1.h
@@ -27,9 +27,15 @@ struct wlr_screencopy_manager_v1 {
 	void *data;
 };
 
+struct wlr_screencopy_v1_client {
+	int ref;
+	struct wlr_screencopy_manager_v1 *manager;
+	struct wl_list damages;
+};
+
 struct wlr_screencopy_frame_v1 {
 	struct wl_resource *resource;
-	struct wlr_screencopy_manager_v1 *manager;
+	struct wlr_screencopy_v1_client *client;
 	struct wl_list link;
 
 	enum wl_shm_format format;
@@ -38,6 +44,8 @@ struct wlr_screencopy_frame_v1 {
 
 	bool overlay_cursor, cursor_locked;
 
+	bool with_damage;
+
 	struct wl_shm_buffer *buffer;
 	struct wl_listener buffer_destroy;
 
diff --git a/types/wlr_screencopy_v1.c b/types/wlr_screencopy_v1.c
index a535c10d..92caa15d 100644
--- a/types/wlr_screencopy_v1.c
+++ b/types/wlr_screencopy_v1.c
@@ -8,10 +8,119 @@
 #include "wlr-screencopy-unstable-v1-protocol.h"
 #include "util/signal.h"
 
-#define SCREENCOPY_MANAGER_VERSION 1
+#define SCREENCOPY_MANAGER_VERSION 2
+
+struct screencopy_damage {
+	struct wl_list link;
+	struct wlr_output *output;
+	struct pixman_region32 damage;
+	struct wl_listener output_precommit;
+	struct wl_listener output_destroy;
+	uint32_t last_commit_seq;
+};
 
 static const struct zwlr_screencopy_frame_v1_interface frame_impl;
 
+static struct screencopy_damage *screencopy_damage_find(
+		struct wlr_screencopy_v1_client *client,
+		struct wlr_output *output) {
+	struct screencopy_damage *damage;
+
+	wl_list_for_each(damage, &client->damages, link) {
+		if (damage->output == output) {
+			return damage;
+		}
+	}
+
+	return NULL;
+}
+
+static void screencopy_damage_accumulate(struct screencopy_damage *damage) {
+	struct pixman_region32 *region = &damage->damage;
+	struct wlr_output *output = damage->output;
+
+	/* This check is done so damage that has been added and cleared in the
+	 * frame precommit handler is not added again after it has been handled.
+	 */
+	if (damage->last_commit_seq == output->commit_seq) {
+		return;
+	}
+
+	pixman_region32_union(region, region, &output->pending.damage);
+	pixman_region32_intersect_rect(region, region, 0, 0, output->width,
+		output->height);
+	damage->last_commit_seq = output->commit_seq;
+}
+
+static void screencopy_damage_handle_output_precommit(
+		struct wl_listener *listener, void *data) {
+	struct screencopy_damage *damage =
+		wl_container_of(listener, damage, output_precommit);
+	screencopy_damage_accumulate(damage);
+}
+
+static void screencopy_damage_destroy(struct screencopy_damage *damage) {
+	wl_list_remove(&damage->output_destroy.link);
+	wl_list_remove(&damage->output_precommit.link);
+	wl_list_remove(&damage->link);
+	pixman_region32_fini(&damage->damage);
+	free(damage);
+}
+
+static void screencopy_damage_handle_output_destroy(
+		struct wl_listener *listener, void *data) {
+	struct screencopy_damage *damage =
+		wl_container_of(listener, damage, output_destroy);
+	screencopy_damage_destroy(damage);
+}
+
+static struct screencopy_damage *screencopy_damage_create(
+		struct wlr_screencopy_v1_client *client,
+		struct wlr_output *output) {
+	struct screencopy_damage *damage =
+		calloc(1, sizeof(struct screencopy_damage));
+	if (!damage) {
+		return NULL;
+	}
+
+	damage->output = output;
+	damage->last_commit_seq = output->commit_seq - 1;
+	pixman_region32_init_rect(&damage->damage, 0, 0, output->width,
+		output->height);
+	wl_list_insert(&client->damages, &damage->link);
+
+	wl_signal_add(&output->events.precommit, &damage->output_precommit);
+	damage->output_precommit.notify =
+		screencopy_damage_handle_output_precommit;
+
+	wl_signal_add(&output->events.destroy, &damage->output_destroy);
+	damage->output_destroy.notify = screencopy_damage_handle_output_destroy;
+
+	return damage;
+}
+
+static struct screencopy_damage *screencopy_damage_get_or_create(
+		struct wlr_screencopy_v1_client *client,
+		struct wlr_output *output) {
+	struct screencopy_damage *damage = screencopy_damage_find(client, output);
+	return damage ? damage : screencopy_damage_create(client, output);
+}
+
+static void client_unref(struct wlr_screencopy_v1_client *client) {
+	assert(client->ref > 0);
+
+	if (--client->ref != 0) {
+		return;
+	}
+
+	struct screencopy_damage *damage, *tmp_damage;
+	wl_list_for_each_safe(damage, tmp_damage, &client->damages, link) {
+		screencopy_damage_destroy(damage);
+	}
+
+	free(client);
+}
+
 static struct wlr_screencopy_frame_v1 *frame_from_resource(
 		struct wl_resource *resource) {
 	assert(wl_resource_instance_of(resource,
@@ -36,6 +145,7 @@ static void frame_destroy(struct wlr_screencopy_frame_v1 *frame) {
 	wl_list_remove(&frame->buffer_destroy.link);
 	// Make the frame resource inert
 	wl_resource_set_user_data(frame->resource, NULL);
+	client_unref(frame->client);
 	free(frame);
 }
 
@@ -52,6 +162,17 @@ static void frame_handle_output_precommit(struct wl_listener *listener,
 		return;
 	}
 
+	struct screencopy_damage *damage = NULL;
+	if (frame->with_damage) {
+		damage = screencopy_damage_get_or_create(frame->client, output);
+		if (damage) {
+			screencopy_damage_accumulate(damage);
+			if (!pixman_region32_not_empty(&damage->damage)) {
+				return;
+			}
+		}
+	}
+
 	wl_list_remove(&frame->output_precommit.link);
 	wl_list_init(&frame->output_precommit.link);
 
@@ -81,6 +202,22 @@ static void frame_handle_output_precommit(struct wl_listener *listener,
 
 	zwlr_screencopy_frame_v1_send_flags(frame->resource, flags);
 
+	// TODO: send fine-grained damage events
+	if (damage) {
+		struct pixman_box32 *damage_box =
+			pixman_region32_extents(&damage->damage);
+
+		int damage_x = damage_box->x1;
+		int damage_y = damage_box->y1;
+		int damage_width = damage_box->x2 - damage_box->x1;
+		int damage_height = damage_box->y2 - damage_box->y1;
+
+		zwlr_screencopy_frame_v1_send_damage(frame->resource,
+			damage_x, damage_y, damage_width, damage_height);
+
+		pixman_region32_clear(&damage->damage);
+	}
+
 	time_t tv_sec = event->when->tv_sec;
 	uint32_t tv_sec_hi = (sizeof(tv_sec) > 4) ? tv_sec >> 32 : 0;
 	uint32_t tv_sec_lo = tv_sec & 0xFFFFFFFF;
@@ -116,7 +253,7 @@ static void frame_handle_buffer_destroy(struct wl_listener *listener,
 	frame_destroy(frame);
 }
 
-static void frame_handle_copy(struct wl_client *client,
+static void frame_handle_copy(struct wl_client *wl_client,
 		struct wl_resource *frame_resource,
 		struct wl_resource *buffer_resource) {
 	struct wlr_screencopy_frame_v1 *frame = frame_from_resource(frame_resource);
@@ -185,7 +322,18 @@ static void frame_handle_copy(struct wl_client *client,
 	}
 }
 
-static void frame_handle_destroy(struct wl_client *client,
+static void frame_handle_copy_with_damage(struct wl_client *wl_client,
+		struct wl_resource *frame_resource,
+		struct wl_resource *buffer_resource) {
+	struct wlr_screencopy_frame_v1 *frame = frame_from_resource(frame_resource);
+	if (frame == NULL) {
+		return;
+	}
+	frame->with_damage = true;
+	frame_handle_copy(wl_client, frame_resource, buffer_resource);
+}
+
+static void frame_handle_destroy(struct wl_client *wl_client,
 		struct wl_resource *frame_resource) {
 	wl_resource_destroy(frame_resource);
 }
@@ -193,6 +341,7 @@ static void frame_handle_destroy(struct wl_client *client,
 static const struct zwlr_screencopy_frame_v1_interface frame_impl = {
 	.copy = frame_handle_copy,
 	.destroy = frame_handle_destroy,
+	.copy_with_damage = frame_handle_copy_with_damage,
 };
 
 static void frame_handle_resource_destroy(struct wl_resource *frame_resource) {
@@ -203,38 +352,41 @@ static void frame_handle_resource_destroy(struct wl_resource *frame_resource) {
 
 static const struct zwlr_screencopy_manager_v1_interface manager_impl;
 
-static struct wlr_screencopy_manager_v1 *manager_from_resource(
+static struct wlr_screencopy_v1_client *client_from_resource(
 		struct wl_resource *resource) {
 	assert(wl_resource_instance_of(resource,
 		&zwlr_screencopy_manager_v1_interface, &manager_impl));
 	return wl_resource_get_user_data(resource);
 }
 
-static void capture_output(struct wl_client *client,
-		struct wlr_screencopy_manager_v1 *manager, uint32_t version, uint32_t id,
-		int32_t overlay_cursor, struct wlr_output *output,
+static void capture_output(struct wl_client *wl_client,
+		struct wlr_screencopy_v1_client *client, uint32_t version,
+		uint32_t id, int32_t overlay_cursor, struct wlr_output *output,
 		const struct wlr_box *box) {
 	struct wlr_screencopy_frame_v1 *frame =
 		calloc(1, sizeof(struct wlr_screencopy_frame_v1));
 	if (frame == NULL) {
-		wl_client_post_no_memory(client);
+		wl_client_post_no_memory(wl_client);
 		return;
 	}
-	frame->manager = manager;
 	frame->output = output;
 	frame->overlay_cursor = !!overlay_cursor;
 
-	frame->resource = wl_resource_create(client,
+	frame->resource = wl_resource_create(wl_client,
 		&zwlr_screencopy_frame_v1_interface, version, id);
 	if (frame->resource == NULL) {
 		free(frame);
-		wl_client_post_no_memory(client);
+		wl_client_post_no_memory(wl_client);
 		return;
 	}
+
+	frame->client = client;
+	client->ref++;
+
 	wl_resource_set_implementation(frame->resource, &frame_impl, frame,
 		frame_handle_resource_destroy);
 
-	wl_list_insert(&manager->frames, &frame->link);
+	wl_list_insert(&client->manager->frames, &frame->link);
 
 	wl_list_init(&frame->output_precommit.link);
 	wl_list_init(&frame->output_enable.link);
@@ -283,23 +435,24 @@ error:
 	frame_destroy(frame);
 }
 
-static void manager_handle_capture_output(struct wl_client *client,
+static void manager_handle_capture_output(struct wl_client *wl_client,
 		struct wl_resource *manager_resource, uint32_t id,
 		int32_t overlay_cursor, struct wl_resource *output_resource) {
-	struct wlr_screencopy_manager_v1 *manager =
-		manager_from_resource(manager_resource);
+	struct wlr_screencopy_v1_client *client =
+		client_from_resource(manager_resource);
 	uint32_t version = wl_resource_get_version(manager_resource);
 	struct wlr_output *output = wlr_output_from_resource(output_resource);
 
-	capture_output(client, manager, version, id, overlay_cursor, output, NULL);
+	capture_output(wl_client, client, version, id, overlay_cursor, output,
+		NULL);
 }
 
-static void manager_handle_capture_output_region(struct wl_client *client,
+static void manager_handle_capture_output_region(struct wl_client *wl_client,
 		struct wl_resource *manager_resource, uint32_t id,
 		int32_t overlay_cursor, struct wl_resource *output_resource,
 		int32_t x, int32_t y, int32_t width, int32_t height) {
-	struct wlr_screencopy_manager_v1 *manager =
-		manager_from_resource(manager_resource);
+	struct wlr_screencopy_v1_client *client =
+		client_from_resource(manager_resource);
 	uint32_t version = wl_resource_get_version(manager_resource);
 	struct wlr_output *output = wlr_output_from_resource(output_resource);
 
@@ -309,10 +462,11 @@ static void manager_handle_capture_output_region(struct wl_client *client,
 		.width = width,
 		.height = height,
 	};
-	capture_output(client, manager, version, id, overlay_cursor, output, &box);
+	capture_output(wl_client, client, version, id, overlay_cursor, output,
+		&box);
 }
 
-static void manager_handle_destroy(struct wl_client *client,
+static void manager_handle_destroy(struct wl_client *wl_client,
 		struct wl_resource *manager_resource) {
 	wl_resource_destroy(manager_resource);
 }
@@ -324,23 +478,41 @@ static const struct zwlr_screencopy_manager_v1_interface manager_impl = {
 };
 
 void manager_handle_resource_destroy(struct wl_resource *resource) {
+	struct wlr_screencopy_v1_client *client =
+		client_from_resource(resource);
+	client_unref(client);
 	wl_list_remove(wl_resource_get_link(resource));
 }
 
-static void manager_bind(struct wl_client *client, void *data, uint32_t version,
-		uint32_t id) {
+static void manager_bind(struct wl_client *wl_client, void *data,
+		uint32_t version, uint32_t id) {
 	struct wlr_screencopy_manager_v1 *manager = data;
 
-	struct wl_resource *resource = wl_resource_create(client,
+	struct wlr_screencopy_v1_client *client =
+		calloc(1, sizeof(struct wlr_screencopy_v1_client));
+	if (client == NULL) {
+		goto failure;
+	}
+
+	struct wl_resource *resource = wl_resource_create(wl_client,
 		&zwlr_screencopy_manager_v1_interface, version, id);
 	if (resource == NULL) {
-		wl_client_post_no_memory(client);
-		return;
+		goto failure;
 	}
-	wl_resource_set_implementation(resource, &manager_impl, manager,
+
+	client->ref = 1;
+	client->manager = manager;
+	wl_list_init(&client->damages);
+
+	wl_resource_set_implementation(resource, &manager_impl, client,
 		manager_handle_resource_destroy);
 
 	wl_list_insert(&manager->resources, wl_resource_get_link(resource));
+
+	return;
+failure:
+	free(client);
+	wl_client_post_no_memory(wl_client);
 }
 
 static void handle_display_destroy(struct wl_listener *listener, void *data) {