Added a graph class for representing and manipulating the game data

graph.h

@@ -0,0 +1,48 @@
+/* Represents an undirected graph.
+ * Also contains the vertex and edge classes
+ * vertexes know their center point on the SDL Surface - 
+ * bad decoupling maybe, but not too bad, all things considered
+ */
+
+#ifndef _GRAPH_H_
+#define _GRAPH_H_
+
+#include <list>
+
+using std::list;
+
+struct Vertex
+{
+    int x;
+    int y;
+    int min_x;
+    int min_y;
+    int max_x;
+    int max_y;
+};
+
+struct Edge
+{
+    Vertex a;
+    Vertex b;
+};
+
+class Graph
+{
+ public:
+    Graph() {}
+
+    bool vertex_present(int x, int y, int size);
+
+    list<Vertex> get_vertices() { return vertices; }
+    list<Edge> get_edges() { return edges; }
+
+    void add_vertex(Vertex v);
+
+ private:
+    Vertex last_vertex;
+    list<Vertex> vertices;
+    list<Edge> edges;
+};
+
+#endif