slightly refactor some zoom stuff

POLISH.md

@@ -0,0 +1,15 @@
+# Polish
+
+Overlapping with TODO.md and docs/backlog.md, we have... a new list of visible
+things needing polish!
+
+- sometimes UI zooms in at once, then unzooms slowly
+- sidewalk paths start in building centers and end in sidewalk centers
+	- this is probably fine to show agents moving, but at least draw
+	  building layer before sidewalk layer
+- the colors are awful
+- different lane markings
+	- sidewalks with little horizontal lines
+	- parking with... circled P's and maybe partial horizontal lines to
+	  show spots?
+	- copy the green Seattle color scheme for bike lanes

TODO.md

@@ -71,7 +71,6 @@
 	- line type / ditch vec2d / settle on types
 
 	- one-at-a-time UI plugins
-	- UI plugins track their own active state
 	- UI colors in one place
 
 	- cleaner pipeline of map construction

editor/src/ui.rs

@@ -131,15 +131,8 @@ impl UI {
             }
         }
 
-        // TODO or make a custom event for zoom change
-        let old_zoom = -1.0;
         let new_zoom = ui.canvas.cam_zoom;
-        ui.show_roads.handle_zoom(old_zoom, new_zoom);
-        ui.show_buildings.handle_zoom(old_zoom, new_zoom);
-        ui.show_intersections.handle_zoom(old_zoom, new_zoom);
-        ui.show_parcels.handle_zoom(old_zoom, new_zoom);
-        ui.show_icons.handle_zoom(old_zoom, new_zoom);
-        ui.debug_mode.handle_zoom(old_zoom, new_zoom);
+        ui.zoom_for_toggleable_layers(-1.0, new_zoom);
 
         ui
     }
@@ -199,13 +192,7 @@ impl UI {
         let old_zoom = self.canvas.cam_zoom;
         self.canvas.handle_event(input.use_event_directly());
         let new_zoom = self.canvas.cam_zoom;
-
-        self.show_roads.handle_zoom(old_zoom, new_zoom);
-        self.show_buildings.handle_zoom(old_zoom, new_zoom);
-        self.show_intersections.handle_zoom(old_zoom, new_zoom);
-        self.show_parcels.handle_zoom(old_zoom, new_zoom);
-        self.show_icons.handle_zoom(old_zoom, new_zoom);
-        self.debug_mode.handle_zoom(old_zoom, new_zoom);
+        self.zoom_for_toggleable_layers(old_zoom, new_zoom);
 
         if !edit_mode {
             if self.show_roads.handle_event(input) {
@@ -399,6 +386,16 @@ impl UI {
         self.canvas.draw_osd_notification(g, &osd_lines);
     }
 
+    // TODO or make a custom event for zoom change
+    fn zoom_for_toggleable_layers(&mut self, old_zoom: f64, new_zoom: f64) {
+        self.show_roads.handle_zoom(old_zoom, new_zoom);
+        self.show_buildings.handle_zoom(old_zoom, new_zoom);
+        self.show_intersections.handle_zoom(old_zoom, new_zoom);
+        self.show_parcels.handle_zoom(old_zoom, new_zoom);
+        self.show_icons.handle_zoom(old_zoom, new_zoom);
+        self.debug_mode.handle_zoom(old_zoom, new_zoom);
+    }
+
     fn mouseover_something(&self, window_size: &Size) -> Option<ID> {
         let (x, y) = self.canvas.get_cursor_in_map_space();