Added code for building data files

native/route_search.cpp

@@ -112,6 +112,8 @@ struct CurrentAreaSearch {
 };
 
 // Data
+// For backwards compatibility, default code is EPSG:32633 (UTM zone 33)
+char const *epsgCode = "EPSG:32633";
 RoadNodeSet set;
 SearchResult lastSearchResult;
 std::set<uint32_t> excludedNodes;
@@ -214,10 +216,29 @@ void loadData(std::string filePath) {
 		addLinkToRoadNode(set.roadNodes, fromPoint, toPoint, speedLimit, motorway, tunnel, passableSameDirection, passableOppositeDirection);
 		addLinkToRoadNode(set.roadNodes, toPoint, fromPoint, speedLimit, motorway, tunnel, passableOppositeDirection, passableSameDirection);
 	}
+
+	// Finally, check if the file contains a string describing the EPSG code of its coordinates. For backwards compatibility, this
+	// field may not be there
+	source.read(buffer, 4);
+	if (!source.eof()) {
+		uint32_t lengthOfString = ntohl(*reinterpret_cast<uint32_t*>(buffer));
+		// I think it is technically a memory leak to create this buffer without eventually destroying it, but it should
+		// only happen once, and it's tiny, so I don't care.
+		char* stringBuffer = new char[lengthOfString+1];
+		source.read(stringBuffer, lengthOfString);
+		*(stringBuffer + lengthOfString) = 0;
+
+		epsgCode = stringBuffer;
+	}
 	
 	delete[] buffer;
 }
 
+// Get the EPSG code
+std::string getEpsgCode() {
+	return std::string(epsgCode);
+}
+
 // Search functions
 JSNodeInfo findClosestNode(float positionX, float positionY) {
 	float closestDistance = 1e99;
@@ -1002,6 +1023,7 @@ EMSCRIPTEN_BINDINGS(my_module) {
 	emscripten::register_vector<AreaSearchEntry>("AreaSearchEntries");
 	
 	emscripten::function("loadData", &loadData);
+	emscripten::function("getEpsgCode", &getEpsgCode);
 	emscripten::function("findClosestNode", &findClosestNode);
 	emscripten::function("findAllPathsFromPoint", &findAllPathsFromPointJS);
 	emscripten::function("getPath", &getPathJS);