Rerwite everything to share an egui context

src/window/vip/world.rs

@@ -2,7 +2,7 @@ use std::{fmt::Display, sync::Arc};
 
 use egui::{
     Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
-    TextureOptions, Ui, ViewportBuilder, ViewportId,
+    TextureOptions, Ui, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use fixed::{
@@ -506,10 +506,6 @@ impl WorldWindow {
 }
 
 impl AppWindow for WorldWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of(format!("world-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }