Automatically calculate weight from distance

src/dijkstragraph.c

@@ -147,6 +147,17 @@ struct dijkstra_path *dijkstra_path_dup_shallow(struct dijkstra_path *path)
 	return dup;
 }
 
+dijkstra_cost dijkstra_get_weight_from_distance(struct dijkstra_node *node_a,
+						struct dijkstra_node *node_b)
+{
+	float dist;
+
+	dist = sqrt(pow(node_a->position.x - node_b->position.x, 2) +
+		    pow(node_a->position.y - node_b->position.y, 2));
+
+	return (dijkstra_cost) dist;
+}
+
 /*!
  * \brief dijkstra_path_new creates a new dijkstra_path between two nodes.
  * \param name the name of the path (pointer is not copied and must stay valid!)
@@ -162,6 +173,10 @@ struct dijkstra_path *dijkstra_path_new(char *name,
 	path = malloc(sizeof(*path));
 	if (path) {
 		path->name = name;
+		if (path->weight == DIJKSTRA_WEIGHT_AUTO)
+			path->weight = dijkstra_get_weight_from_distance(source,
+									 destination);
+		else
 			path->weight = weight;
 
 		dijkstra_connect_nodes_to_path(source, destination, path);

src/dijkstragraph.h

@@ -3,6 +3,8 @@
 
 #include <glib.h>
 
+#define DIJKSTRA_WEIGHT_AUTO (-1)
+
 typedef int dijkstra_cost;
 
 struct dijkstra_solver {

src/geojson.c

@@ -83,7 +83,8 @@ int add_geojson_to_dijkstra(struct dijkstra_solver *solver,
 								dijkstra_path_new_to_list(solver,
 											  x_last, y_last,
 											  x, y,
-											  name, 1);
+											  name,
+											  DIJKSTRA_WEIGHT_AUTO);
 							}
 
 							x_last = x;