Add blur, shadow, and corner radius to layer-shell surfaces (#144)

Co-authored-by: Will McKinnon <contact@willmckinnon.com>

README.md

@@ -31,6 +31,14 @@ Sway is an incredible window manager, and certainly one of the most well establi
     - `blur_xray enable|disable`
     - `blur_passes <integer value 0 - 10>`
     - `blur_radius <integer value 0 - 10>`
++ LayerShell effects: *ONLY ON SWAYFX-GIT, NOT YET RELEASED*
+    - `layer_effects <layer namespace> <effects>`
+    - Example: `layer_effects "waybar" blur enable; shadows enable; corner_radius 6`
+    - SwayIPC Example: `swaymsg "layer_effects 'waybar' 'blur enable; shadows enable; corner_radius 6'"`
+    - Available Effects:
+        - `blur <enable|disable>`
+        - `shadows <enable|disable>`
+        - `corner_radius <int>`
 + Dim unfocused windows:
     - `default_dim_inactive <float value 0.0 - 1.0>`
     - `for_window [CRITERIA_HERE] dim_inactive <float value 0.0 - 1.0>`

include/sway/commands.h

@@ -97,6 +97,11 @@ void container_resize_tiled(struct sway_container *parent, uint32_t axis,
 struct sway_container *container_find_resize_parent(struct sway_container *con,
 		uint32_t edge);
 
+/**
+ * Effect handlers value parsers
+ */
+bool cmd_corner_radius_parse_value(char *arg, int* result);
+
 /**
  * Handlers shared by exec and exec_always.
  */
@@ -157,6 +162,7 @@ sway_cmd cmd_input;
 sway_cmd cmd_seat;
 sway_cmd cmd_ipc;
 sway_cmd cmd_kill;
+sway_cmd cmd_layer_effects;
 sway_cmd cmd_layout;
 sway_cmd cmd_log_colors;
 sway_cmd cmd_mark;

include/sway/config.h

@@ -500,6 +500,8 @@ struct sway_config {
 	bool titlebar_separator;
 	bool scratchpad_minimize;
 
+	list_t *layer_criteria;
+
 	char *swaynag_command;
 	struct swaynag_instance swaynag_config_errors;
 	list_t *symbols;
@@ -765,6 +767,8 @@ int config_get_blur_size();
 
 bool config_should_parameters_blur();
 
+bool config_should_parameters_shadow();
+
 /* Global config singleton. */
 extern struct sway_config *config;
 

include/sway/desktop/fx_renderer/fx_renderer.h

@@ -33,6 +33,7 @@ struct decoration_data {
 	float *dim_color;
 	bool has_titlebar;
 	bool blur;
+	bool shadow;
 };
 
 struct blur_shader {

include/sway/layer_criteria.h

@@ -0,0 +1,20 @@
+#include <stdbool.h>
+#include "sway/layers.h"
+#include "sway/config.h"
+
+struct layer_criteria {
+	char *namespace;
+	char *cmdlist;
+};
+
+void layer_criteria_destroy(struct layer_criteria *criteria);
+
+bool layer_criteria_is_equal(struct layer_criteria *a, struct layer_criteria *b);
+
+bool layer_criteria_already_exists(struct layer_criteria *criteria);
+
+// Gathers all of the matching criterias for a specified `sway_layer_surface`
+list_t *layer_criterias_for_sway_layer_surface(struct sway_layer_surface *sway_layer);
+
+// Parses the `layer_criteria` and applies the effects to the `sway_layer_surface`
+void layer_criteria_parse(struct sway_layer_surface *sway_layer, struct layer_criteria *criteria);

include/sway/layers.h

@@ -27,6 +27,10 @@ struct sway_layer_surface {
 	enum zwlr_layer_shell_v1_layer layer;
 
 	struct wl_list subsurfaces;
+
+	bool has_shadow;
+	bool has_blur;
+	int corner_radius;
 };
 
 struct sway_layer_popup {

include/sway/output.h

@@ -13,6 +13,12 @@
 struct sway_server;
 struct sway_container;
 
+struct render_data {
+	pixman_region32_t *damage;
+	struct wlr_box *clip_box;
+	struct decoration_data deco_data;
+};
+
 struct sway_output_state {
 	list_t *workspaces;
 	struct sway_workspace *active_workspace;

sway/commands.c

@@ -84,6 +84,7 @@ static const struct cmd_handler handlers[] = {
 	{ "gaps", cmd_gaps },
 	{ "hide_edge_borders", cmd_hide_edge_borders },
 	{ "input", cmd_input },
+	{ "layer_effects", cmd_layer_effects },
 	{ "mode", cmd_mode },
 	{ "mouse_warping", cmd_mouse_warping },
 	{ "new_float", cmd_new_float },

sway/commands/blur.c

@@ -12,7 +12,7 @@ struct cmd_results *cmd_blur(int argc, char **argv) {
 
 	struct sway_container *con = config->handler_context.container;
 
-	bool result = parse_boolean(argv[0], config->blur_enabled);
+	bool result = parse_boolean(argv[0], true);
 	if (con == NULL) {
 		config->blur_enabled = result;
 	} else {

sway/commands/corner_radius.c

@@ -4,15 +4,24 @@
 #include "sway/tree/container.h"
 #include "log.h"
 
+bool cmd_corner_radius_parse_value(char *arg, int* result) {
+	char *inv;
+	int value = strtol(arg, &inv, 10);
+	if (*inv != '\0' || value < 0 || value > 99) {
+		return false;
+	}
+	*result = value;
+	return true;
+}
+
 struct cmd_results *cmd_corner_radius(int argc, char **argv) {
 	struct cmd_results *error = NULL;
 	if ((error = checkarg(argc, "corner_radius", EXPECTED_EQUAL_TO, 1))) {
 		return error;
 	}
 
-	char *inv;
+	int value = 0;
-	int value = strtol(argv[0], &inv, 10);
+	if (!cmd_corner_radius_parse_value(argv[0], &value)) {
-	if (*inv != '\0' || value < 0 || value > 99) {
 		return cmd_results_new(CMD_FAILURE, "Invalid size specified");
 	}
 

sway/commands/layer_effects.c

@@ -0,0 +1,33 @@
+#include <ctype.h>
+#include "log.h"
+#include "stringop.h"
+#include "sway/commands.h"
+#include "sway/config.h"
+#include "sway/layer_criteria.h"
+#include "sway/output.h"
+#include "util.h"
+
+struct cmd_results *cmd_layer_effects(int argc, char **argv) {
+	struct cmd_results *error = NULL;
+	if ((error = checkarg(argc, "layer_effects", EXPECTED_AT_LEAST, 2))) {
+		return error;
+	}
+
+	struct layer_criteria *criteria = malloc(sizeof(struct layer_criteria));
+	criteria->namespace = malloc(strlen(argv[0]) + 1);
+	strcpy(criteria->namespace, argv[0]);
+	criteria->cmdlist = join_args(argv + 1, argc - 1);
+
+	// Check if the rule already exists
+	if (layer_criteria_already_exists(criteria)) {
+		sway_log(SWAY_DEBUG, "layer_effect already exists: '%s' '%s'",
+				criteria->namespace, criteria->cmdlist);
+		layer_criteria_destroy(criteria);
+		return cmd_results_new(CMD_SUCCESS, NULL);
+	}
+
+	list_add(config->layer_criteria, criteria);
+	sway_log(SWAY_DEBUG, "layer_effect: '%s' '%s' added", criteria->namespace, criteria->cmdlist);
+
+	return cmd_results_new(CMD_SUCCESS, NULL);
+}

sway/commands/shadows.c

@@ -17,7 +17,7 @@ struct cmd_results *cmd_shadows(int argc, char **argv) {
 
 	struct sway_container *con = config->handler_context.container;
 
-	bool result = parse_boolean(argv[0], config->shadow_enabled);
+	bool result = parse_boolean(argv[0], true);
 	if (con == NULL) {
 		config->shadow_enabled = result;
 	} else {

sway/config.c

@@ -21,6 +21,7 @@
 #include "sway/commands.h"
 #include "sway/config.h"
 #include "sway/criteria.h"
+#include "sway/layer_criteria.h"
 #include "sway/desktop/transaction.h"
 #include "sway/swaynag.h"
 #include "sway/tree/arrange.h"
@@ -157,6 +158,12 @@ void free_config(struct sway_config *config) {
 		}
 		list_free(config->criteria);
 	}
+	if (config->layer_criteria) {
+		for (int i = 0; i < config->layer_criteria->length; ++i) {
+			layer_criteria_destroy(config->layer_criteria->items[i]);
+		}
+		list_free(config->layer_criteria);
+	}
 	list_free(config->no_focus);
 	list_free(config->active_bar_modifiers);
 	list_free_items_and_destroy(config->config_chain);
@@ -354,6 +361,8 @@ static void config_defaults(struct sway_config *config) {
 	config->titlebar_separator = true;
 	config->scratchpad_minimize = true;
 
+	if (!(config->layer_criteria = create_list())) goto cleanup;
+
 	// The keysym to keycode translation
 	struct xkb_rule_names rules = {0};
 	config->keysym_translation_state =
@@ -1092,3 +1101,7 @@ int config_get_blur_size() {
 bool config_should_parameters_blur() {
 	return config->blur_params.radius > 0 && config->blur_params.num_passes > 0;
 }
+
+bool config_should_parameters_shadow() {
+	return config->shadow_blur_sigma > 0 && config->shadow_color[3] > 0.0;
+}

sway/desktop/layer_shell.c

@@ -6,6 +6,7 @@
 #include <wlr/types/wlr_output.h>
 #include <wlr/types/wlr_subcompositor.h>
 #include "log.h"
+#include "sway/layer_criteria.h"
 #include "sway/desktop/transaction.h"
 #include "sway/input/cursor.h"
 #include "sway/input/input-manager.h"
@@ -15,6 +16,21 @@
 #include "sway/server.h"
 #include "sway/tree/arrange.h"
 #include "sway/tree/workspace.h"
+#include "wlr-layer-shell-unstable-v1-protocol.h"
+
+static void layer_parse_criteria(struct sway_layer_surface *sway_layer) {
+	enum zwlr_layer_shell_v1_layer layer = sway_layer->layer;
+	if (layer == ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND) {
+		return;
+	}
+
+	list_t *criterias = layer_criterias_for_sway_layer_surface(sway_layer);
+	for (int i = 0; i < criterias->length; i++) {
+		struct layer_criteria *criteria = criterias->items[i];
+		layer_criteria_parse(sway_layer, criteria);
+	}
+	list_free(criterias);
+}
 
 static void apply_exclusive(struct wlr_box *usable_area,
 		uint32_t anchor, int32_t exclusive,
@@ -306,6 +322,7 @@ static void handle_surface_commit(struct wl_listener *listener, void *data) {
 			wl_list_insert(&output->layers[layer_surface->current.layer],
 				&layer->link);
 			layer->layer = layer_surface->current.layer;
+			layer_parse_criteria(layer);
 		}
 		arrange_layers(output);
 	}
@@ -393,6 +410,7 @@ static void handle_map(struct wl_listener *listener, void *data) {
 	struct wlr_output *wlr_output = sway_layer->layer_surface->output;
 	sway_assert(wlr_output, "wlr_layer_surface_v1 has null output");
 	struct sway_output *output = wlr_output->data;
+	layer_parse_criteria(sway_layer);
 	output_damage_surface(output, sway_layer->geo.x, sway_layer->geo.y,
 		sway_layer->layer_surface->surface, true);
 	wlr_surface_send_enter(sway_layer->layer_surface->surface,
@@ -685,6 +703,10 @@ void handle_layer_shell_surface(struct wl_listener *listener, void *data) {
 	sway_layer->layer_surface = layer_surface;
 	layer_surface->data = sway_layer;
 
+	sway_layer->has_blur = false;
+	sway_layer->has_shadow = false;
+	sway_layer->corner_radius = 0;
+
 	struct sway_output *output = layer_surface->output->data;
 	sway_layer->output_destroy.notify = handle_output_destroy;
 	wl_signal_add(&output->events.disable, &sway_layer->output_destroy);

sway/desktop/output.c

@@ -199,6 +199,13 @@ void output_layer_for_each_toplevel_surface(struct sway_output *output,
 	wl_list_for_each(layer_surface, layer_surfaces, link) {
 		struct wlr_layer_surface_v1 *wlr_layer_surface_v1 =
 			layer_surface->layer_surface;
+
+		struct render_data *data = user_data;
+		data->deco_data.blur = layer_surface->layer != ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND ?
+			layer_surface->has_blur : false;
+		data->deco_data.shadow = layer_surface->has_shadow;
+		data->deco_data.corner_radius = layer_surface->corner_radius;
+
 		output_surface_for_each_surface(output, wlr_layer_surface_v1->surface,
 			layer_surface->geo.x, layer_surface->geo.y, iterator,
 			user_data);

sway/desktop/render.c

@@ -23,7 +23,6 @@
 #include "sway/desktop/fx_renderer/fx_renderer.h"
 #include "sway/input/input-manager.h"
 #include "sway/input/seat.h"
-#include "sway/layers.h"
 #include "sway/output.h"
 #include "sway/server.h"
 #include "sway/tree/arrange.h"
@@ -32,12 +31,6 @@
 #include "sway/tree/view.h"
 #include "sway/tree/workspace.h"
 
-struct render_data {
-	pixman_region32_t *damage;
-	struct wlr_box *clip_box;
-	struct decoration_data deco_data;
-};
-
 struct decoration_data get_undecorated_decoration_data() {
 	return (struct decoration_data) {
 		.alpha = 1.0f,
@@ -47,10 +40,10 @@ struct decoration_data get_undecorated_decoration_data() {
 		.saturation = 1.0f,
 		.has_titlebar = false,
 		.blur = false,
+		.shadow = false,
 	};
 }
 
-
 // TODO: contribute wlroots function to allow creating an fbox from a box?
 struct wlr_fbox wlr_fbox_from_wlr_box(struct wlr_box *box) {
 	return (struct wlr_fbox) {
@@ -357,6 +350,61 @@ damage_finish:
 	pixman_region32_fini(&inverse_opaque);
 }
 
+// _box.x and .y are expected to be layout-local
+// _box.width and .height are expected to be output-buffer-local
+void render_box_shadow(struct sway_output *output, pixman_region32_t *output_damage,
+		const struct wlr_box *_box, const float color[static 4],
+		float blur_sigma, float corner_radius) {
+	struct wlr_output *wlr_output = output->wlr_output;
+	struct fx_renderer *renderer = output->renderer;
+
+	struct wlr_box box;
+	memcpy(&box, _box, sizeof(struct wlr_box));
+	box.x -= blur_sigma;
+	box.y -= blur_sigma;
+	box.width += 2 * blur_sigma;
+	box.height += 2 * blur_sigma;
+
+	pixman_region32_t damage = create_damage(box, output_damage);
+
+	// don't damage area behind window since we dont render it anyway
+	struct wlr_box inner_box;
+	memcpy(&inner_box, _box, sizeof(struct wlr_box));
+	inner_box.x += corner_radius;
+	inner_box.y += corner_radius;
+	inner_box.width -= 2 * corner_radius;
+	inner_box.height -= 2 * corner_radius;
+	pixman_region32_t inner_damage = create_damage(inner_box, output_damage);
+	pixman_region32_subtract(&damage, &damage, &inner_damage);
+
+	bool damaged = pixman_region32_not_empty(&damage);
+	if (!damaged) {
+		goto damage_finish;
+	}
+
+	float matrix[9];
+	wlr_matrix_project_box(matrix, &box, WL_OUTPUT_TRANSFORM_NORMAL, 0,
+			wlr_output->transform_matrix);
+
+	// ensure the box is updated as per the output orientation
+	struct wlr_box transformed_box;
+	int width, height;
+	wlr_output_transformed_resolution(wlr_output, &width, &height);
+	wlr_box_transform(&transformed_box, &box,
+			wlr_output_transform_invert(wlr_output->transform), width, height);
+
+	int nrects;
+	pixman_box32_t *rects = pixman_region32_rectangles(&damage, &nrects);
+	for (int i = 0; i < nrects; ++i) {
+		scissor_output(wlr_output, &rects[i]);
+
+		fx_render_box_shadow(renderer, &transformed_box, color, matrix,
+				corner_radius, blur_sigma);
+	}
+
+damage_finish:
+	pixman_region32_fini(&damage);
+}
 
 static void render_surface_iterator(struct sway_output *output,
 		struct sway_view *view, struct wlr_surface *surface,
@@ -421,6 +469,7 @@ static void render_surface_iterator(struct sway_output *output,
 		pixman_region32_fini(&opaque_region);
 	}
 
+	// Render surface texture
 	struct wlr_fbox src_box;
 	wlr_surface_get_buffer_source_box(surface, &src_box);
 	struct fx_texture fx_texture = fx_texture_from_wlr_texture(texture);
@@ -431,6 +480,30 @@ static void render_surface_iterator(struct sway_output *output,
 		wlr_output);
 }
 
+// view will be NULL every time
+static void render_layer_iterator(struct sway_output *output,
+		struct sway_view *view, struct wlr_surface *surface,
+		struct wlr_box *_box, void *_data) {
+	struct render_data *data = _data;
+	struct decoration_data deco_data = data->deco_data;
+
+	// Ignore effects if this is a subsurface
+	if (wl_list_length(&surface->current.subsurfaces_above) > 0) {
+		deco_data = get_undecorated_decoration_data();
+	}
+
+	// render the layer's surface
+	render_surface_iterator(output, view, surface, _box, _data);
+
+	// render shadow
+	if (deco_data.shadow && config_should_parameters_shadow()) {
+		int corner_radius = deco_data.corner_radius *= output->wlr_output->scale;
+		scale_box(_box, output->wlr_output->scale);
+		render_box_shadow(output, data->damage, _box, config->shadow_color,
+				config->shadow_blur_sigma, corner_radius);
+	}
+}
+
 static void render_layer_toplevel(struct sway_output *output,
 		pixman_region32_t *damage, struct wl_list *layer_surfaces) {
 	struct render_data data = {
@@ -438,7 +511,7 @@ static void render_layer_toplevel(struct sway_output *output,
 		.deco_data = get_undecorated_decoration_data(),
 	};
 	output_layer_for_each_toplevel_surface(output, layer_surfaces,
-		render_surface_iterator, &data);
+		render_layer_iterator, &data);
 }
 
 static void render_layer_popups(struct sway_output *output,
@@ -448,7 +521,7 @@ static void render_layer_popups(struct sway_output *output,
 		.deco_data = get_undecorated_decoration_data(),
 	};
 	output_layer_for_each_popup_surface(output, layer_surfaces,
-		render_surface_iterator, &data);
+		render_layer_iterator, &data);
 }
 
 #if HAVE_XWAYLAND
@@ -633,62 +706,6 @@ damage_finish:
 	pixman_region32_fini(&damage);
 }
 
-// _box.x and .y are expected to be layout-local
-// _box.width and .height are expected to be output-buffer-local
-void render_box_shadow(struct sway_output *output, pixman_region32_t *output_damage,
-		const struct wlr_box *_box, const float color[static 4],
-		float blur_sigma, float corner_radius) {
-	struct wlr_output *wlr_output = output->wlr_output;
-	struct fx_renderer *renderer = output->renderer;
-
-	struct wlr_box box;
-	memcpy(&box, _box, sizeof(struct wlr_box));
-	box.x -= blur_sigma;
-	box.y -= blur_sigma;
-	box.width += 2 * blur_sigma;
-	box.height += 2 * blur_sigma;
-
-	pixman_region32_t damage = create_damage(box, output_damage);
-
-	// don't damage area behind window since we dont render it anyway
-	struct wlr_box inner_box;
-	memcpy(&inner_box, _box, sizeof(struct wlr_box));
-	inner_box.x += corner_radius;
-	inner_box.y += corner_radius;
-	inner_box.width -= 2 * corner_radius;
-	inner_box.height -= 2 * corner_radius;
-	pixman_region32_t inner_damage = create_damage(inner_box, output_damage);
-	pixman_region32_subtract(&damage, &damage, &inner_damage);
-
-	bool damaged = pixman_region32_not_empty(&damage);
-	if (!damaged) {
-		goto damage_finish;
-	}
-
-	float matrix[9];
-	wlr_matrix_project_box(matrix, &box, WL_OUTPUT_TRANSFORM_NORMAL, 0,
-			wlr_output->transform_matrix);
-
-	// ensure the box is updated as per the output orientation
-	struct wlr_box transformed_box;
-	int width, height;
-	wlr_output_transformed_resolution(wlr_output, &width, &height);
-	wlr_box_transform(&transformed_box, &box,
-			wlr_output_transform_invert(wlr_output->transform), width, height);
-
-	int nrects;
-	pixman_box32_t *rects = pixman_region32_rectangles(&damage, &nrects);
-	for (int i = 0; i < nrects; ++i) {
-		scissor_output(wlr_output, &rects[i]);
-
-		fx_render_box_shadow(renderer, &transformed_box, color, matrix,
-				corner_radius, blur_sigma);
-	}
-
-damage_finish:
-	pixman_region32_fini(&damage);
-}
-
 void premultiply_alpha(float color[4], float opacity) {
 	color[3] *= opacity;
 	color[0] *= color[3];
@@ -807,6 +824,7 @@ static void render_saved_view(struct sway_view *view, struct sway_output *output
 			}
 		}
 
+		// Render saved surface texture
 		struct fx_texture fx_texture = fx_texture_from_wlr_texture(saved_buf->buffer->texture);
 		render_texture(wlr_output, damage, &fx_texture,
 				&saved_buf->source_box, &dst_box, matrix, deco_data);
@@ -833,7 +851,6 @@ static void render_view(struct sway_output *output, pixman_region32_t *damage,
 		render_view_toplevels(view, output, damage, deco_data);
 	}
 
-	// Only draw shadows on CSD windows if shadows_on_csd is enabled
 	if (state->border == B_CSD && !config->shadows_on_csd_enabled) {
 		return;
 	}
@@ -1404,6 +1421,7 @@ static void render_containers_linear(struct sway_output *output,
 				.saturation = child->saturation,
 				.has_titlebar = has_titlebar,
 				.blur = child->blur_enabled,
+				.shadow = child->shadow_enabled,
 			};
 			render_view(output, damage, child, colors, deco_data);
 			if (has_titlebar) {
@@ -1453,6 +1471,7 @@ static void render_containers_tabbed(struct sway_output *output,
 		.saturation = current->saturation,
 		.has_titlebar = true,
 		.blur = current->blur_enabled,
+		.shadow = current->shadow_enabled,
 	};
 
 	// Render tabs
@@ -1548,6 +1567,7 @@ static void render_containers_stacked(struct sway_output *output,
 				? 0 : current->corner_radius,
 		.has_titlebar = true,
 		.blur = current->blur_enabled,
+		.shadow = current->shadow_enabled,
 	};
 
 	// Render titles
@@ -1695,6 +1715,7 @@ static void render_floating_container(struct sway_output *soutput,
 			.corner_radius = con->corner_radius,
 			.has_titlebar = has_titlebar,
 			.blur = con->blur_enabled,
+			.shadow = con->shadow_enabled,
 		};
 		render_view(soutput, damage, con, colors, deco_data);
 		if (has_titlebar) {
@@ -1927,6 +1948,7 @@ void output_render(struct sway_output *output, struct timespec *when,
 			.saturation = focus->saturation,
 			.has_titlebar = false,
 			.blur = false,
+			.shadow = false,
 		};
 		render_view_popups(focus->view, output, damage, deco_data);
 	}

sway/ipc-json.c

@@ -10,6 +10,7 @@
 #include "log.h"
 #include "sway/config.h"
 #include "sway/ipc-json.h"
+#include "sway/layers.h"
 #include "sway/tree/container.h"
 #include "sway/tree/view.h"
 #include "sway/tree/workspace.h"
@@ -273,7 +274,8 @@ static json_object *ipc_json_create_node(int id, const char* type, char *name,
 	return object;
 }
 
-static void ipc_json_describe_wlr_output(struct wlr_output *wlr_output, json_object *object) {
+static void ipc_json_describe_wlr_output(struct wlr_output *wlr_output,
+		struct sway_output *output, json_object *object) {
 	json_object_object_add(object, "primary", json_object_new_boolean(false));
 	json_object_object_add(object, "make",
 			json_object_new_string(wlr_output->make ? wlr_output->make : "Unknown"));
@@ -299,7 +301,7 @@ static void ipc_json_describe_wlr_output(struct wlr_output *wlr_output, json_obj
 
 static void ipc_json_describe_output(struct sway_output *output,
 		json_object *object) {
-	ipc_json_describe_wlr_output(output->wlr_output, object);
+	ipc_json_describe_wlr_output(output->wlr_output, output, object);
 }
 
 static void ipc_json_describe_enabled_output(struct sway_output *output,
@@ -331,6 +333,63 @@ static void ipc_json_describe_enabled_output(struct sway_output *output,
 	json_object_object_add(object, "adaptive_sync_status",
 		json_object_new_string(adaptive_sync_status));
 
+	struct json_object *layers = json_object_new_array();
+	size_t len = sizeof(output->layers) / sizeof(output->layers[0]);
+	for (size_t i = 0; i < len; ++i) {
+		struct sway_layer_surface *lsurface;
+		wl_list_for_each(lsurface, &output->layers[i], link) {
+			json_object *layer = json_object_new_object();
+
+			json_object_object_add(layer, "namespace",
+				json_object_new_string(lsurface->layer_surface->namespace));
+
+			char *layer_name;
+			switch (lsurface->layer) {
+				case ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND:
+					layer_name = "background";
+					break;
+				case ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM:
+					layer_name = "bottom";
+					break;
+				case ZWLR_LAYER_SHELL_V1_LAYER_TOP:
+					layer_name = "top";
+					break;
+				case ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY:
+					layer_name = "overlay";
+					break;
+			}
+
+			json_object_object_add(layer, "layer",
+				json_object_new_string(layer_name));
+
+			json_object *extent = json_object_new_object();
+			json_object_object_add(extent, "width",
+					json_object_new_int(lsurface->extent.width));
+			json_object_object_add(extent, "height",
+					json_object_new_int(lsurface->extent.height));
+			json_object_object_add(extent, "x",
+					json_object_new_int(lsurface->extent.x));
+			json_object_object_add(extent, "y",
+					json_object_new_int(lsurface->extent.y));
+			json_object_object_add(layer, "extent", extent);
+
+			json_object *effects = json_object_new_array();
+			if (lsurface->has_blur) {
+				json_object_array_add(effects, json_object_new_string("blur"));
+			}
+			if (lsurface->has_shadow) {
+				json_object_array_add(effects, json_object_new_string("shadows"));
+			}
+			if (lsurface->corner_radius > 0) {
+				json_object_array_add(effects, json_object_new_string("corner_radius"));
+			}
+			json_object_object_add(layer, "effects", effects);
+
+			json_object_array_add(layers, layer);
+		}
+	}
+	json_object_object_add(object, "layer_shell_surfaces", layers);
+
 	struct sway_workspace *ws = output_get_active_workspace(output);
 	if (!sway_assert(ws, "Expected output to have a workspace")) {
 		return;
@@ -413,7 +472,7 @@ json_object *ipc_json_describe_non_desktop_output(struct sway_output_non_desktop
 
 	json_object *object = json_object_new_object();
 
-	ipc_json_describe_wlr_output(wlr_output, object);
+	ipc_json_describe_wlr_output(wlr_output, NULL, object);
 
 	json_object_object_add(object, "non_desktop", json_object_new_boolean(true));
 	json_object_object_add(object, "type", json_object_new_string("output"));

sway/layer_criteria.c

@@ -0,0 +1,88 @@
+#include <ctype.h>
+#include "log.h"
+#include "stringop.h"
+#include "sway/commands.h"
+#include "sway/layer_criteria.h"
+#include "util.h"
+
+void layer_criteria_destroy(struct layer_criteria *criteria) {
+	free(criteria->namespace);
+	free(criteria->cmdlist);
+	free(criteria);
+}
+
+bool layer_criteria_is_equal(struct layer_criteria *a, struct layer_criteria *b) {
+	return strcmp(a->namespace, b->namespace) == 0
+		&& strcmp(a->cmdlist, b->cmdlist) == 0;
+}
+
+bool layer_criteria_already_exists(struct layer_criteria *criteria) {
+	list_t *criterias = config->layer_criteria;
+	for (int i = 0; i < criterias->length; ++i) {
+		struct layer_criteria *existing = criterias->items[i];
+		if (layer_criteria_is_equal(criteria, existing)) {
+			return true;
+		}
+	}
+	return false;
+}
+
+list_t *layer_criterias_for_sway_layer_surface(struct sway_layer_surface *sway_layer) {
+	list_t *criterias = config->layer_criteria;
+	list_t *matches = create_list();
+	for (int i = 0; i < criterias->length; ++i) {
+		struct layer_criteria *criteria = criterias->items[i];
+		if (strcmp(criteria->namespace, sway_layer->layer_surface->namespace) == 0) {
+			list_add(matches, criteria);
+		}
+	}
+	return matches;
+}
+
+void layer_criteria_parse(struct sway_layer_surface *sway_layer, struct layer_criteria *criteria) {
+	char matched_delim = ';';
+	char *head = malloc(strlen(criteria->cmdlist) + 1);
+	strcpy(head, criteria->cmdlist);
+	do {
+		// Trim leading whitespaces
+		for (; isspace(*head); ++head) {}
+		// Split command list
+		char *cmd = argsep(&head, ";,", &matched_delim);
+		for (; isspace(*cmd); ++cmd) {}
+
+		if (strcmp(cmd, "") == 0) {
+			sway_log(SWAY_INFO, "Ignoring empty layer effect.");
+			continue;
+		}
+		sway_log(SWAY_INFO, "Handling layer effect '%s'", cmd);
+
+		int argc;
+		char **argv = split_args(cmd, &argc);
+		// Strip all quotes from each token
+		for (int i = 1; i < argc; ++i) {
+			if (*argv[i] == '\"' || *argv[i] == '\'') {
+				strip_quotes(argv[i]);
+			}
+		}
+		if (strcmp(argv[0], "blur") == 0) {
+			sway_layer->has_blur = parse_boolean(argv[1], true);
+			continue;
+		} else if (strcmp(argv[0], "shadows") == 0) {
+			sway_layer->has_shadow = parse_boolean(argv[1], true);
+			continue;
+		} else if (strcmp(argv[0], "corner_radius") == 0) {
+			int value;
+			if (cmd_corner_radius_parse_value(argv[1], &value)) {
+				sway_layer->corner_radius = value;
+				continue;
+			}
+			sway_log(SWAY_ERROR,
+					"Invalid layer_effects corner_radius size! Got \"%s\"",
+					argv[1]);
+			return;
+		} else {
+			sway_log(SWAY_ERROR, "Invalid layer_effects effect! Got \"%s\"", cmd);
+			return;
+		}
+	} while(head);
+}

sway/meson.build

@@ -5,6 +5,7 @@ sway_sources = files(
 	'decoration.c',
 	'ipc-json.c',
 	'ipc-server.c',
+	'layer_criteria.c',
 	'lock.c',
 	'main.c',
 	'realtime.c',
@@ -91,6 +92,7 @@ sway_sources = files(
 	'commands/include.c',
 	'commands/input.c',
 	'commands/layout.c',
+	'commands/layer_effects.c',
 	'commands/mode.c',
 	'commands/mouse_warping.c',
 	'commands/move.c',

sway/sway-ipc.7.scd

@@ -230,6 +230,11 @@ following properties:
 :  string
 :  The transform currently in use for the output. This can be _normal_, _90_,
    _180_, _270_, _flipped-90_, _flipped-180_, or _flipped-270_
+|- layer_shell_surfaces
+:  array
+:  An array of all layer-shell surfaces attached to the output. Each object
+   contains _namespace_, _layer_, _effects_, and _extent_ object that contains _x_, _y_
+   _width_, and _height_
 |- current_workspace
 :  string
 :  The workspace currently visible on the output or _null_ for disabled outputs
@@ -259,6 +264,35 @@ following properties:
 		"scale": 1.0,
 		"subpixel_hinting": "rgb",
 		"transform": "normal",
+		"layer_shell_surfaces": [
+			{
+				"namespace": "wallpaper",
+				"layer": "background",
+				"extent": {
+					"width": 2560,
+					"height": 1440,
+					"x": 0,
+					"y": 0
+				},
+				"effects": [
+				]
+			},
+			{
+				"namespace": "waybar",
+				"layer": "top",
+				"extent": {
+					"width": 2548,
+					"height": 31,
+					"x": 6,
+					"y": 6
+				},
+				"effects": [
+					"blur",
+					"shadow",
+					"corner_rounding"
+				]
+			}
+		],
 		"current_workspace": "1",
 		"modes": [
 			{

sway/sway.5.scd

@@ -787,6 +787,25 @@ The default colors are:
 	Whenever a window that matches _criteria_ appears, run list of commands.
 	See *CRITERIA* for more details.
 
+*layer_effects* <layer-namespace> <effects>
+	Apply effects on specific layer shell surfaces, eg "waybar" or "rofi".
+	At least one effect needs to be provided. The <layer-namespace> can be
+	gotten through *sway-ipc*. Note: Surfaces in the _bottom_ layer cannot
+	use these effects.
+
+	Effects:
+	- *blur* <enable|disable>
+	- *shadows* <enable|disable>
+	- *corner_radius* <integer>
+
+	Example:
+
+		layer_effects "waybar" blur enable; shadows enable; corner_radius 6
+
+	SwayIPC Example:
+
+		swaymsg "layer_effects 'waybar' 'blur enable; shadows enable'"
+
 *gaps* inner|outer|horizontal|vertical|top|right|bottom|left <amount>
 	Sets default _amount_ pixels of _inner_ or _outer_ gap, where the inner
 	affects spacing around each view and outer affects the spacing around each

sway/tree/workspace.c

@@ -5,11 +5,13 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <strings.h>
+#include <wayland-util.h>
 #include "stringop.h"
 #include "sway/input/input-manager.h"
 #include "sway/input/cursor.h"
 #include "sway/input/seat.h"
 #include "sway/ipc-server.h"
+#include "sway/layers.h"
 #include "sway/output.h"
 #include "sway/tree/arrange.h"
 #include "sway/tree/container.h"
@@ -702,7 +704,25 @@ bool should_workspace_have_blur(struct sway_workspace *ws) {
 	if (!workspace_is_visible(ws)) {
 		return false;
 	}
-	return (bool)workspace_find_container(ws, find_blurred_con_iterator, NULL);
+
+	if ((bool)workspace_find_container(ws, find_blurred_con_iterator, NULL)) {
+		return true;
+	}
+
+	// Check if any layer-shell surfaces will render effects
+	struct sway_output *sway_output = ws->output;
+	size_t len = sizeof(sway_output->layers) / sizeof(sway_output->layers[0]);
+	for (size_t i = 0; i < len; ++i) {
+		struct sway_layer_surface *lsurface;
+		wl_list_for_each(lsurface, &sway_output->layers[i], link) {
+			if (lsurface->has_blur && !lsurface->layer_surface->surface->opaque
+					&& lsurface->layer != ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND) {
+				return true;
+			}
+		}
+	}
+
+	return false;
 }
 
 void workspace_for_each_container(struct sway_workspace *ws,