Add support for layer-shell drop-shadows

README.md

@@ -53,6 +53,7 @@ Sway is an incredible window manager, and certainly one of the most well establi
             blur_xray enable;
             blur_ignore_transparent enable;
             shadows enable;
+            use_drop_shadow enable;
             corner_radius 20;
         }
         ```
@@ -61,6 +62,7 @@ Sway is an incredible window manager, and certainly one of the most well establi
         - `blur_xray <enable|disable>`
         - `blur_ignore_transparent <enable|disable>`
         - `shadows <enable|disable>`
+        - `use_drop_shadow <enable|disable>`
         - `corner_radius <int>`
         - `reset`: To reset/disable all previously applied effects to the layer application
 + Dim unfocused windows:

include/sway/layer_criteria.h

@@ -5,6 +5,7 @@ struct layer_criteria {
 	char *cmdlist;
 
 	bool shadow_enabled;
+	bool use_drop_shadow;
 	bool blur_enabled;
 	bool blur_xray;
 	bool blur_ignore_transparent;

include/sway/layers.h

@@ -26,6 +26,7 @@ struct sway_layer_surface {
 	struct wlr_layer_surface_v1 *layer_surface;
 
 	bool shadow_enabled;
+	bool use_drop_shadow;
 	bool blur_enabled;
 	bool blur_xray;
 	bool blur_ignore_transparent;

sway/desktop/layer_shell.c

@@ -60,13 +60,15 @@ void layer_apply_criteria(struct sway_layer_surface *surface, struct layer_crite
 		surface->blur_xray = criteria->blur_xray;
 		surface->blur_ignore_transparent = criteria->blur_ignore_transparent;
 		surface->shadow_enabled = criteria->shadow_enabled;
+		surface->use_drop_shadow = criteria->use_drop_shadow;
 	} else {
 		// Reset
 		surface->corner_radius = 0;
 		surface->blur_enabled = false;
 		surface->blur_xray = false;
 		surface->blur_ignore_transparent = false;
 		surface->shadow_enabled = false;
+		surface->use_drop_shadow = false;
 	}
 }
 
@@ -99,26 +101,27 @@ static void arrange_surface(struct sway_output *output, const struct wlr_box *fu
 		}
 
 		wlr_scene_node_set_enabled(&surface->shadow_node->node, surface->shadow_enabled);
-		if (surface->shadow_enabled) {
-			// Adjust the size and position of the shadow node
-			wlr_scene_shadow_set_size(surface->shadow_node,
-					surface->layer_surface->surface->current.width + config->shadow_blur_sigma * 2,
-					surface->layer_surface->surface->current.height + config->shadow_blur_sigma * 2);
-			int x = config->shadow_offset_x - config->shadow_blur_sigma;
-			int y = config->shadow_offset_y - config->shadow_blur_sigma;
-			wlr_scene_node_set_position(&surface->shadow_node->node, x, y);
-
-			wlr_scene_shadow_set_clipped_region(surface->shadow_node, (struct clipped_region) {
-					.corner_radius = surface->corner_radius,
-					.corners = CORNER_LOCATION_ALL,
-					.area = {
-						.x = -x,
-						.y = -y,
-						.width = surface->layer_surface->surface->current.width,
-						.height = surface->layer_surface->surface->current.height,
-					},
-			});
-		}
+		wlr_scene_shadow_set_type(surface->shadow_node,
+				surface->use_drop_shadow ? WLR_SCENE_SHADOW_TYPE_DROP : WLR_SCENE_SHADOW_TYPE_BOX);
+		// Adjust the size and position of the shadow node
+		const int shadow_size = wlr_scene_shadow_get_offset(surface->shadow_node);
+		wlr_scene_shadow_set_size(surface->shadow_node,
+				surface->layer_surface->surface->current.width + shadow_size * 2,
+				surface->layer_surface->surface->current.height + shadow_size * 2);
+		int x = config->shadow_offset_x - shadow_size;
+		int y = config->shadow_offset_y - shadow_size;
+		wlr_scene_node_set_position(&surface->shadow_node->node, x, y);
+
+		wlr_scene_shadow_set_clipped_region(surface->shadow_node, (struct clipped_region) {
+				.corner_radius = surface->corner_radius,
+				.corners = CORNER_LOCATION_ALL,
+				.area = {
+					.x = -x,
+					.y = -y,
+					.width = surface->layer_surface->surface->current.width,
+					.height = surface->layer_surface->surface->current.height,
+				},
+		});
 
 		wlr_scene_layer_surface_v1_configure(surface->scene, full_area, usable_area);
 	}
@@ -240,6 +243,7 @@ static struct sway_layer_surface *sway_layer_surface_create(
 	surface->blur_xray = false;
 	surface->blur_ignore_transparent = false;
 	surface->shadow_enabled = false;
+	surface->use_drop_shadow = false;
 
 	bool failed = false;
 	surface->shadow_node = alloc_scene_shadow(surface->tree, 0, 0,

sway/desktop/output.c

@@ -279,6 +279,9 @@ void output_configure_scene(struct sway_output *output, struct wlr_scene_node *n
 			wlr_scene_buffer_set_corner_radius(buffer, surface->corner_radius, CORNER_LOCATION_ALL);
 			wlr_scene_shadow_set_blur_sigma(surface->shadow_node, config->shadow_blur_sigma);
 			wlr_scene_shadow_set_corner_radius(surface->shadow_node, surface->corner_radius);
+			if (surface->shadow_node->type == WLR_SCENE_SHADOW_TYPE_DROP) {
+				wlr_scene_shadow_set_reference_buffer(surface->shadow_node, buffer);
+			}
 			wlr_scene_buffer_set_backdrop_blur(buffer, surface->blur_enabled);
 			wlr_scene_buffer_set_backdrop_blur_ignore_transparent(buffer, surface->blur_ignore_transparent);
 			wlr_scene_buffer_set_backdrop_blur_optimized(buffer, surface->blur_xray);

sway/desktop/transaction.c

@@ -417,12 +417,12 @@ static void arrange_container(struct sway_container *con,
 			corner_radius = con->corner_radius + config->border_thickness;
 		}
 
+		const int shadow_size = wlr_scene_shadow_get_offset(con->shadow);
 		wlr_scene_shadow_set_size(con->shadow,
-				width + config->shadow_blur_sigma * 2,
-				height + config->shadow_blur_sigma * 2);
+				width + shadow_size * 2, height + shadow_size * 2);
 
-		int x = config->shadow_offset_x - config->shadow_blur_sigma;
-		int y = config->shadow_offset_y - config->shadow_blur_sigma;
+		int x = config->shadow_offset_x - shadow_size;
+		int y = config->shadow_offset_y - shadow_size;
 		wlr_scene_node_set_position(&con->shadow->node, x, y);
 
 		wlr_scene_shadow_set_clipped_region(con->shadow, (struct clipped_region) {

sway/layer_criteria.c

@@ -13,6 +13,7 @@ static void init_criteria_effects(struct layer_criteria *criteria) {
 	criteria->blur_xray = false;
 	criteria->blur_ignore_transparent = false;
 	criteria->shadow_enabled = false;
+	criteria->use_drop_shadow = false;
 }
 
 static void copy_criteria_effects(struct layer_criteria *dst, struct layer_criteria *src) {
@@ -21,6 +22,7 @@ static void copy_criteria_effects(struct layer_criteria *dst, struct layer_crite
 	dst->blur_xray = src->blur_xray;
 	dst->blur_ignore_transparent = src->blur_ignore_transparent;
 	dst->shadow_enabled = src->shadow_enabled;
+	dst->use_drop_shadow = src->use_drop_shadow;
 }
 
 static bool layer_criteria_find(char *namespace,
@@ -81,6 +83,9 @@ static bool layer_criteria_parse(struct layer_criteria *criteria) {
 		} else if (strcmp(argv[0], "shadows") == 0) {
 			criteria->shadow_enabled = parse_boolean(argv[1], true);
 			continue;
+		} else if (strcmp(argv[0], "use_drop_shadow") == 0) {
+			criteria->use_drop_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/sway.5.scd

@@ -862,6 +862,7 @@ The default colors are:
 	- *blur_xray* <enable|disable>
 	- *blur_ignore_transparent* <enable|disable>
 	- *shadows* <enable|disable>
+	- *use_drop_shadow* <enable|disable>
 	- *corner_radius* <integer>
 	- *reset* Resets all previously applied effects
 	- *reset* To reset/disable all previously applied effects to the layer application
@@ -873,6 +874,7 @@ The default colors are:
 			blur_xray enable;
 			blur_ignore_transparent enable;
 			shadows enable;
+			use_drop_shadow enable;
 			corner_radius 6;
 		}