diff --git a/drawutils.h b/drawutils.h
index 238cc68..a87b1ed 100644
--- a/drawutils.h
+++ b/drawutils.h
@@ -18,7 +18,7 @@ class DrawUtils
     static bool draw(SDL_Surface* dest, SDL_Surface* drawable, int x, int y, 
 		     int x2, int y2, int w, int h);
     static void draw_line(SDL_Surface* dest, Sint16 x1, Sint16 y1, Sint16 x2, Sint16 y2, Uint16 width, Uint32 colour);
-    static void draw_circle_filled(SDL_Surface* dest, Sint16 x, Sint16 y, Uint16 r, Uint32 colour, Uint8 alpha = 255);
+    static void draw_circle_filled(SDL_Surface* dest, Sint16 x, Sint16 y, Uint16 r, Uint32 colour);
 
     // transpare (v) - to make transparent
     static bool transpare(SDL_Surface* surface, int r, int g, int b);
diff --git a/graph.h b/graph.h
index fda14e9..2199096 100644
--- a/graph.h
+++ b/graph.h
@@ -35,16 +35,18 @@ class Graph
 
     bool vertex_present(int x, int y, int size);
 
-    list<Vertex*> get_vertices() { return vertices; }
-    list<Edge> get_edges() { return edges; }
+    list<Vertex*> get_vertices() const { return vertices; }
+    list<Edge> get_edges() const { return edges; }
 
     void select_vertex(int x, int y);
     void do_vertex(int x, int y, int r);
-    Vertex* get_current_vertex() { return current_vertex; }
+
+    Vertex* get_current_vertex() const { return current_vertex; }
+    void clear_current_vertex() { current_vertex = NULL; }
 
  private:
-    bool vertex_would_overlap(int x, int y, int r);
-    bool crosses_edge(Edge e);
+    bool vertex_would_overlap(int x, int y, int r) const;
+    bool crosses_edge(Edge e) const;
     void add_vertex(int x, int y, int r);
 
     Vertex* current_vertex;