added new helper methods to work with ground-truth

made some assertions optional [i know what i am doing!]

floorplan/v2/FloorplanHelper.h

@@ -40,6 +40,31 @@ public:
 		return res;
 	}
 
+	/** get all ground-truth points within the map as hash-map: id->pos */
+	static std::unordered_map<int, Point3> getGroundTruthPoints(const Floorplan::IndoorMap* map) {
+		std::unordered_map<int, Point3> res;
+		for (const Floorplan::Floor* f : map->floors) {
+			for (const Floorplan::GroundTruthPoint* gtp : f->gtpoints) {
+				res[gtp->id] = gtp->getPosition(*f);
+			}
+		}
+		return res;
+	}
+
+	/** get all ground-truth points, identified by the given indices */
+	static std::vector<Point3> getGroundTruth(const Floorplan::IndoorMap* map, const std::vector<int> indices) {
+
+		// get a map id->pos for all ground-truth-points within the map
+		const std::unordered_map<int, Point3> src = getGroundTruthPoints(map);
+		std::vector<Point3> res;
+		for (const int idx : indices) {
+			const auto& it = src.find(idx);
+			if (it == src.end()) {throw Exception("map does not contain a ground-truth-point with ID " + std::to_string(idx));}
+			res.push_back(it->second);
+		}
+		return res;
+	}
+
 public:
 
 	/** align all floorplan values to the given grid size. needed for the grid factory */