Invalidate blur from per-output sampled backdrop damage

compositor/src/state/animation.rs

@@ -468,9 +468,7 @@ impl Ferese {
         self.refresh_workspace_slide_offsets();
         self.sync_window_stacking();
 
-        if active_animation || dim_changed {
-            self.backdrop_generation = self.backdrop_generation.wrapping_add(1);
-        }
+        active_animation |= dim_changed;
         active_animation
     }
 

compositor/src/state/layout.rs

@@ -238,7 +238,7 @@ impl Ferese {
             }
         }
 
-        let mut layout_changed = self.unmap_invisible_windows(&visible);
+        self.unmap_invisible_windows(&visible);
 
         let now = self.start_time.elapsed();
 
@@ -268,7 +268,6 @@ impl Ferese {
             } else {
                 PresentationMode::Normal
             };
-            layout_changed |= !had_geometry || geometry.logical != rect;
             let mut requested_size = geometry.set_presentation_mode(rect, mode, now);
             if !was_mapped && (had_geometry || is_fullscreen) {
                 geometry.settle_presentation();
@@ -405,10 +404,6 @@ impl Ferese {
             }
         }
 
-        if layout_changed {
-            self.backdrop_generation = self.backdrop_generation.wrapping_add(1);
-        }
-
         self.sync_window_stacking();
         self.retarget_overview();
         self.send_shell_snapshots();

compositor/src/state/navigation.rs

@@ -71,7 +71,7 @@ impl Ferese {
         if let Some(swipe) = &mut self.focus_swipe {
             swipe.progress = progress;
         }
-        self.backdrop_generation = self.backdrop_generation.wrapping_add(1);
+
         if let Some(output) = self
             .focus_swipe
             .as_ref()
@@ -440,7 +440,7 @@ impl Ferese {
                 .expect("gesture output exists")
                 .held_progress = Some(progress);
             self.refresh_workspace_slide_offsets();
-            self.backdrop_generation = self.backdrop_generation.wrapping_add(1);
+
             if let Some(output) = self.outputs_by_id.get(&output).cloned() {
                 self.defer_output_redraw(output);
             }
@@ -464,7 +464,7 @@ impl Ferese {
         slide.gesture = Some((from, to, direction));
         self.workspace_slides.insert(output, slide);
         self.swipe.mark_preview_started();
-        self.backdrop_generation = self.backdrop_generation.wrapping_add(1);
+
         self.relayout();
     }