Checking zoom and tiles boundaries (#6)

src/store/map.ts

@@ -1,5 +1,6 @@
 import { createSlice } from '@reduxjs/toolkit';
 import _ from 'lodash';
+import { tileProviders } from '../components/map/tile';
 import { tileSize } from '../components/map/tiled-map';
 import {
   geoPoint,
@@ -121,6 +122,13 @@ const evaluateWhiteboardViewBox = (
 export const evaluateStateFromScope = (state: MapState) => {
   console.log('<<<<<<<<<<<< evaluateStateFromScope');
   state.tiles.zoom = _.round(state.scope.zoom);
+  if (state.tiles.zoom < tileProviders[state.scope.tileProvider].minZoom) {
+    state.tiles.zoom = tileProviders[state.scope.tileProvider].minZoom;
+  }
+  if (state.tiles.zoom > tileProviders[state.scope.tileProvider].maxZoom) {
+    state.tiles.zoom = tileProviders[state.scope.tileProvider].maxZoom;
+  }
+
   const softZoom = state.scope.zoom - state.tiles.zoom;
 
   state.slippy.scale = 2 ** softZoom;
@@ -186,8 +194,11 @@ export const reevaluateState = (state: MapState) => {
       (state.tiles.nb.x - 1) * visibleTileSize - window.innerWidth ||
     -state.slippy.translation.y >
       (state.tiles.nb.y - 1) * visibleTileSize - window.innerHeight ||
-    state.slippy.scale > Math.SQRT2 ||
-    state.slippy.scale < Math.SQRT1_2
+    (state.slippy.scale > Math.SQRT2 &&
+      state.tiles.zoom + 1 <=
+        tileProviders[state.scope.tileProvider].maxZoom) ||
+    (state.slippy.scale < Math.SQRT1_2 &&
+      state.tiles.zoom - 1 >= tileProviders[state.scope.tileProvider].minZoom)
   ) {
     evaluateStateFromScope(state);
   } else {