From a5d6b0f2659f32e011659ef7d8de933a88974271 Mon Sep 17 00:00:00 2001
From: Julian Orth <ju.orth@gmail.com>
Date: Wed, 8 May 2024 13:04:19 +0200
Subject: [PATCH] layer-shell: consider sub-surface extents during positioning

---
 src/ifs/wl_surface/zwlr_layer_surface_v1.rs | 28 ++++++++++-----------
 src/renderer.rs                             | 13 +++-------
 src/tree/output.rs                          |  2 +-
 3 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/src/ifs/wl_surface/zwlr_layer_surface_v1.rs b/src/ifs/wl_surface/zwlr_layer_surface_v1.rs
index e2e274f3..6f974fff 100644
--- a/src/ifs/wl_surface/zwlr_layer_surface_v1.rs
+++ b/src/ifs/wl_surface/zwlr_layer_surface_v1.rs
@@ -45,7 +45,7 @@ pub struct ZwlrLayerSurfaceV1 {
     pub output: Rc<OutputGlobalOpt>,
     pub namespace: String,
     pub tracker: Tracker<Self>,
-    output_pos: Cell<Rect>,
+    output_extents: Cell<Rect>,
     pos: Cell<Rect>,
     mapped: Cell<bool>,
     layer: Cell<u32>,
@@ -106,7 +106,7 @@ impl ZwlrLayerSurfaceV1 {
             output: output.clone(),
             namespace: namespace.to_string(),
             tracker: Default::default(),
-            output_pos: Default::default(),
+            output_extents: Default::default(),
             pos: Default::default(),
             mapped: Cell::new(false),
             layer: Cell::new(layer),
@@ -284,19 +284,16 @@ impl ZwlrLayerSurfaceV1 {
         }
     }
 
-    pub fn output_position(&self) -> Rect {
-        self.output_pos.get()
-    }
-
-    pub fn position(&self) -> Rect {
-        self.pos.get()
+    pub fn output_extents(&self) -> Rect {
+        self.output_extents.get()
     }
 
     fn compute_position(&self) {
         let Some(global) = self.output.get() else {
             return;
         };
-        let (width, height) = self.size.get();
+        let extents = self.surface.extents.get();
+        let (width, height) = extents.size();
         let mut anchor = self.anchor.get();
         if anchor == 0 {
             anchor = LEFT | RIGHT | TOP | BOTTOM;
@@ -320,9 +317,11 @@ impl ZwlrLayerSurfaceV1 {
         }
         let o_rect = Rect::new_sized(x1, y1, width, height).unwrap();
         let a_rect = o_rect.move_(opos.x1(), opos.y1());
-        self.output_pos.set(o_rect);
+        self.output_extents.set(o_rect);
         self.pos.set(a_rect);
-        self.surface.set_absolute_position(a_rect.x1(), a_rect.y1());
+        let abs_x = a_rect.x1() - extents.x1();
+        let abs_y = a_rect.y1() - extents.y1();
+        self.surface.set_absolute_position(abs_x, abs_y);
         self.client.state.tree_changed();
     }
 
@@ -360,9 +359,7 @@ impl SurfaceExt for ZwlrLayerSurfaceV1 {
             if !buffer_is_some {
                 self.destroy_node();
             } else {
-                let pos = self.pos.get();
-                let (width, height) = self.size.get();
-                if width != pos.width() || height != pos.height() {
+                if self.surface.extents.get().size() != self.pos.get().size() {
                     self.compute_position();
                 }
             }
@@ -437,7 +434,8 @@ impl Node for ZwlrLayerSurfaceV1 {
         tree: &mut Vec<FoundNode>,
         _usecase: FindTreeUsecase,
     ) -> FindTreeResult {
-        self.surface.find_tree_at_(x, y, tree)
+        let (dx, dy) = self.surface.extents.get().position();
+        self.surface.find_tree_at_(x + dx, y + dy, tree)
     }
 
     fn node_render(&self, renderer: &mut Renderer, x: i32, y: i32, _bounds: Option<&Rect>) {
diff --git a/src/renderer.rs b/src/renderer.rs
index 6821c49b..85244e24 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -103,12 +103,8 @@ impl Renderer<'_> {
         macro_rules! render_layer {
             ($layer:expr) => {
                 for ls in $layer.iter() {
-                    let pos = ls.position();
-                    self.render_layer_surface(
-                        ls.deref(),
-                        x + pos.x1() - opos.x1(),
-                        y + pos.y1() - opos.y1(),
-                    );
+                    let pos = ls.output_extents();
+                    self.render_layer_surface(ls.deref(), x + pos.x1(), y + pos.y1());
                     self.base.ops.push(GfxApiOpt::Sync);
                 }
             };
@@ -539,8 +535,7 @@ impl Renderer<'_> {
     }
 
     pub fn render_layer_surface(&mut self, surface: &ZwlrLayerSurfaceV1, x: i32, y: i32) {
-        let body = surface.position().at_point(x, y);
-        let body = self.base.scale_rect(body);
-        self.render_surface(&surface.surface, x, y, Some(&body));
+        let (dx, dy) = surface.surface.extents.get().position();
+        self.render_surface(&surface.surface, x - dx, y - dy, None);
     }
 }
diff --git a/src/tree/output.rs b/src/tree/output.rs
index 0aabc9f4..459046ea 100644
--- a/src/tree/output.rs
+++ b/src/tree/output.rs
@@ -582,7 +582,7 @@ impl OutputNode {
         let len = tree.len();
         for layer in layers.iter().copied() {
             for surface in self.layers[layer as usize].rev_iter() {
-                let pos = surface.output_position();
+                let pos = surface.output_extents();
                 if pos.contains(x, y) {
                     let (x, y) = pos.translate(x, y);
                     if surface.node_find_tree_at(x, y, tree, usecase)