From aa6b2fcd79ffcd5e30b16b302dca9277395e97f3 Mon Sep 17 00:00:00 2001
From: Erik Reider <35975961+ErikReider@users.noreply.github.com>
Date: Fri, 19 May 2023 05:14:37 +0200
Subject: [PATCH] Fix damage being extended after clearing the previous frame
 (#158)

* Fix damage being extended after clearing the previous frame

* Ensure that damage expansion only occurs if it's smaller than the monitor
---
 sway/desktop/output.c | 14 +++++++++++++-
 sway/desktop/render.c | 14 ++++++++++----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 45bbf0b8..c3c240f8 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -692,7 +692,19 @@ static void damage_surface_iterator(struct sway_output *output,
 
 	if (view) {
 		int blur_size = view->container->blur_enabled ? config_get_blur_size() : 0;
-		wlr_region_expand(&damage, &damage, blur_size);
+
+		if (pixman_region32_not_empty(&damage)) {
+			int output_width, output_height;
+			wlr_output_transformed_resolution(output->wlr_output, &output_width, &output_height);
+			int32_t damage_width = damage.extents.x2 - damage.extents.x1;
+			int32_t damage_height = damage.extents.y2 - damage.extents.y1;
+			if (damage_width > output_width || damage_height > output_height) {
+				pixman_region32_intersect_rect(&damage, &damage, 0, 0, output_width, output_height);
+			} else {
+				wlr_region_expand(&damage, &damage, blur_size);
+			}
+		}
+
 		box.x -= blur_size;
 		box.y -= blur_size;
 		box.width += blur_size * 2;
diff --git a/sway/desktop/render.c b/sway/desktop/render.c
index 77765b1d..f587d3da 100644
--- a/sway/desktop/render.c
+++ b/sway/desktop/render.c
@@ -1770,6 +1770,7 @@ void output_render(struct sway_output *output, struct timespec *when,
 
 	if (debug.damage == DAMAGE_RERENDER) {
 		pixman_region32_union_rect(damage, damage, 0, 0, output_width, output_height);
+		pixman_region32_copy(&extended_damage, damage);
 	}
 
 	if (!pixman_region32_not_empty(damage)) {
@@ -1856,8 +1857,14 @@ void output_render(struct sway_output *output, struct timespec *when,
 		render_unmanaged(output, damage, &root->xwayland_unmanaged);
 #endif
 	} else {
-		bool should_render_blur = should_workspace_have_blur(workspace);
-		if (should_render_blur) {
+		bool workspace_has_blur = should_workspace_have_blur(workspace);
+		if (workspace_has_blur) {
+			if (config_should_parameters_blur() && renderer->blur_buffer_dirty) {
+				// Needs to be extended before clearing
+				pixman_region32_union_rect(damage, damage, 0, 0, output_width, output_height);
+				pixman_region32_union_rect(&extended_damage, &extended_damage, 0, 0, output_width, output_height);
+			}
+
 			// ensure that the damage isn't expanding past the output's size
 			int32_t damage_width = damage->extents.x2 - damage->extents.x1;
 			int32_t damage_height = damage->extents.y2 - damage->extents.y1;
@@ -1884,8 +1891,7 @@ void output_render(struct sway_output *output, struct timespec *when,
 			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM]);
 
 		// check if the background needs to be blurred
-		if (config_should_parameters_blur() && renderer->blur_buffer_dirty && should_render_blur) {
-			pixman_region32_union_rect(damage, damage, 0, 0, output_width, output_height);
+		if (config_should_parameters_blur() && renderer->blur_buffer_dirty && workspace_has_blur) {
 			render_output_blur(output, damage);
 		}