Some more work now stuff is rendered corectly

crates/eframe/src/native/run.rs

@@ -980,7 +980,6 @@ mod glow_integration {
                         let window = &mut *window.write();
                         if let Some(winit_state) = &mut window.egui_winit {
                             if let Some(win) = window.window.clone() {
-                                println!("Render beagin!");
                                 let win = win.read();
                                 let input = winit_state.take_egui_input(&win);
                                 let output =
@@ -1026,7 +1025,6 @@ mod glow_integration {
                                             "failed to get current context to swap buffers",
                                         ));
                                 }
-                                println!("Should render sync");
                                 return;
                             }
                         }

crates/egui/src/context.rs

@@ -189,7 +189,7 @@ struct ContextImpl {
     frame_stack: Vec<(u64, u64)>,
 
     // The output of a frame:
-    graphics: GraphicLayers,
+    graphics: HashMap<u64, GraphicLayers>,
     output: PlatformOutput,
 
     paint_stats: PaintStats,
@@ -241,6 +241,17 @@ impl ContextImpl {
         viewport_id: u64,
         parent_viewport_id: u64,
     ) {
+        // This is used to pause the last frame
+        if !self.frame_stack.is_empty() {
+            let viewport_id = self.get_viewport_id();
+            println!("Pause: {viewport_id}");
+            self.layer_rects_prev_viewports.insert(
+                viewport_id,
+                std::mem::take(&mut self.layer_rects_this_frame),
+            );
+            self.memory.pause_frame(viewport_id);
+        }
+
         self.frame_stack.push((viewport_id, parent_viewport_id));
         self.repaint.start_frame(self.get_viewport_id());
 
@@ -581,7 +592,7 @@ impl Context {
     /// Read-write access to [`GraphicLayers`], where painted [`crate::Shape`]s are written to.
     #[inline]
     pub(crate) fn graphics_mut<R>(&self, writer: impl FnOnce(&mut GraphicLayers) -> R) -> R {
-        self.write(move |ctx| writer(&mut ctx.graphics))
+        self.write(move |ctx| writer(ctx.graphics.entry(ctx.get_viewport_id()).or_default()))
     }
 
     /// Read-only access to [`PlatformOutput`].
@@ -1459,7 +1470,22 @@ impl Context {
                 })
         });
 
-        self.write(|ctx| ctx.frame_stack.pop());
+        // This is used to resume the last frame!
+        let is_last = self.write(|ctx| {
+            ctx.frame_stack.pop();
+            ctx.frame_stack.is_empty()
+        });
+        if !is_last {
+            let viewport_id = self.get_viewport_id();
+            println!("Resume: {viewport_id}");
+            self.write(|ctx| {
+                ctx.layer_rects_prev_frame = ctx
+                    .layer_rects_prev_viewports
+                    .remove(&viewport_id)
+                    .unwrap_or_default();
+                ctx.memory.resume_frame(viewport_id)
+            });
+        }
         FullOutput {
             platform_output,
             repaint_after,
@@ -1471,7 +1497,13 @@ impl Context {
     }
 
     fn drain_paint_lists(&self) -> Vec<ClippedShape> {
-        self.write(|ctx| ctx.graphics.drain(ctx.memory.areas.order()).collect())
+        self.write(|ctx| {
+            ctx.graphics
+                .entry(ctx.get_viewport_id())
+                .or_default()
+                .drain(ctx.memory.areas.order())
+                .collect()
+        })
     }
 
     /// Tessellate the given shapes into triangle meshes.

crates/egui/src/memory.rs

@@ -385,6 +385,13 @@ impl Memory {
         }
     }
 
+    pub(crate) fn pause_frame(&mut self, viewport_id: u64) {
+        self.interactions
+            .insert(viewport_id, std::mem::take(&mut self.interaction));
+        self.viewports_areas
+            .insert(viewport_id, std::mem::take(&mut self.areas));
+    }
+
     pub(crate) fn end_frame(
         &mut self,
         input: &InputState,
@@ -403,6 +410,11 @@ impl Memory {
         self.viewports_areas.retain(|id, _| viewports.contains(id));
     }
 
+    pub(crate) fn resume_frame(&mut self, viewport_id: u64) {
+        self.interaction = self.interactions.remove(&viewport_id).unwrap();
+        self.areas = self.viewports_areas.remove(&viewport_id).unwrap();
+    }
+
     /// Top-most layer at the given position.
     pub fn layer_id_at(&self, pos: Pos2, resize_interact_radius_side: f32) -> Option<LayerId> {
         self.areas.layer_id_at(pos, resize_interact_radius_side)

examples/viewports/src/main.rs

@@ -8,6 +8,9 @@ fn main() {
 
     let mut to_repair = false;
 
+    let mut show = false;
+    let mut value = 0.0;
+
     let _ = eframe::run_simple_native(
         "Viewports Examples",
         NativeOptions {
@@ -35,10 +38,21 @@ fn main() {
                                 ui.label("Parent Viewport ID: ");
                                 ui.label(format!("{parent_viewport_id}"))
                             });
+                            ui.checkbox(&mut show, "Show");
+                            ui.add(
+                                egui::widgets::DragValue::new(&mut value)
+                                    .clamp_range(-10..=10)
+                                    .speed(0.1),
+                            );
                         })
                     },
                 );
 
+                if show {
+                    ui.label("Is shown!");
+                    ui.label(format!("Value: {value}"));
+                }
+
                 egui::CollapsingHeader::new("Show Test1").show(ui, |ui| {
                     egui::Window::new("Test1").show(ctx, move |ui, id, parent_id| {
                         ui.label(format!("Frame: {}", ui.ctx().frame_nr()));