Implemented a simple collision hash table.

collider.hpp

@@ -0,0 +1,32 @@
+#pragma once
+#include <vector>
+#include <unordered_map>
+#include "map.hpp"
+#include "dinkyecs.hpp"
+#include <tuple>
+
+struct PointHash {
+  size_t operator()(const Point& p) const {
+    return std::hash<int>()(p.x) ^ std::hash<int>()(p.y);
+  }
+};
+
+typedef std::vector<DinkyECS::Entity> FoundList;
+
+class SpatialHashTable {
+  public:
+    SpatialHashTable() {}
+
+    // disable copying, I think?
+    SpatialHashTable(SpatialHashTable &other) = delete;
+
+    void insert(Point pos, DinkyECS::Entity obj);
+    void move(Point from, Point to, DinkyECS::Entity ent);
+    void remove(Point pos);
+    bool occupied(Point pos);
+
+    std::tuple<bool, FoundList> neighbors(Point position);
+
+  private:
+    std::unordered_map<Point, DinkyECS::Entity, PointHash> table;
+};