hopefully better zoom, mini fixes

Author: nobkd

src/bg/bg.js

@@ -23,7 +23,7 @@ function redirect(req) {
   if (req.originUrl && req.url.match(matcher)) {
     if (!disabledHosts.includes(getHostname(req.originUrl))) {
       return {
-        redirectUrl: runtimeMapUrl + '?' + req.url.split('?')[1],
+        redirectUrl: runtimeMapUrl + '?' + req.url.split('?').pop(),
       }
     }
   }

src/map/utils/parsePB.js

@@ -47,7 +47,7 @@ function convertType(item) {
       val = tileTypes[tileIndex < tileTypes.length && tileIndex >= 0 ? tileIndex : 0]
       break
     case 'z': // base64 encoded coords
-      val = Buffer.from(item, 'base64').toString('utf-8')
+      val = Uint8Array.fromBase64(item).toString('utf-8')
   }
 
   return [val, type === 'm']

src/map/utils/read.js

@@ -1,6 +1,6 @@
 import { parsePB, tileTypes } from './parsePB.js'
 import { parseDMS } from './parseDMS.js'
-import { getMapZoom } from './zoom.js'
+import { altitude2zoom } from './zoom.js'
 
 export const nominatimQ = 'https://nominatim.openstreetmap.org/search?limit=1&format=json&q='
 const cidMatch = /^0x[\da-f]+:0x[\da-f]+$/i
@@ -41,13 +41,13 @@ export async function readPB(param) {
   let data = parsePB(param.split('!').slice(1))[0]
 
   /** @type {number[]} */
-  let mapArea = data[0][0]
+  let mapArea = data[0][0].reverse()
   mapData.area = {
-    lat: mapArea[2],
+    lat: mapArea[0],
     lon: mapArea[1],
   }
 
-  mapData.zoom = getMapZoom(mapArea[0])
+  mapData.zoom = altitude2zoom(mapArea[2])
 
   /** @type {any[] | string} */
   let currMarkers = data[1]
@@ -98,6 +98,8 @@ export async function readQ(addr) {
 
   /** @type {LatLon[]} */
   const json = await res.json()
+  if (!json.length) return null
+  
   /** @type {LatLon} */
   const body = json[0]
 

src/map/utils/zoom.js

@@ -1,22 +1,13 @@
-const factor = 35200000
-const precision = 10
+const earthCircumference = 40_075_000.017 // in m
+const factor = 1.25
 
 /**
  * Converts *altitude over the map* to *zoom level of the map*
- * TODO: Should be rewritten!!!
+ * https://stackoverflow.com/a/37142662
  *
- * Reference: https://groups.google.com/g/google-earth-browser-plugin/c/eSL9GlAkWBk/m/T4mdToJz_FgJ
- * @param {number} alt Altitude as number
- * @returns {number} Zoom level between 0 and 19
+ * @param {number} alt Altitude in m
+ * @returns {number} Zoom level
  */
-export function getMapZoom(alt) {
-  let zoom = Math.log2(factor / alt) * 1.225
-  zoom = Math.round((zoom + Number.EPSILON) * precision) / precision
-
-  if (zoom < 0) {
-    zoom = 0
-  } else if (zoom > 19) {
-    zoom = 19
-  }
-  return zoom
+export function altitude2zoom(alt) {
+  return (Math.log2(earthCircumference / alt) + 1) * factor
 }