Rewrite planemap and idalloc in pure C++

luprex/syscpp/planemap.hpp

@@ -0,0 +1,91 @@
+//
+// PLANEMAP
+//
+// Stores a map of the items that are on each plane.  Doesn't
+// store terrain, only items.
+//
+// A plane is a rectangle, with a finite size: if you stray more
+// than 80,000,000 meters from the origin, then you are beyond the
+// edge of the plane.
+//
+// There's nothing stopping you from moving a PlaneItem farther
+// than that.  However, if you do move a PlaneItem farther than
+// that, then it won't show up in radius-scans.
+//
+// The PlaneMap doesn't need you to "create" planes.  You just
+// set the plane of a PlaneItem to any string, and that plane will
+// pop into existence if it wasn't already there.
+//
+// If you use the empty string as a plane name, a special case is
+// triggered: you're "nowhere."  Radius scans can never find items
+// whose plane is the empty string.
+//
+// INHERITANCE
+//
+// The intent is that class Sprite should derive from PlaneItem.
+// When you put sprites into a PlaneMap, it will work fine.  However,
+// when you scan the PlaneMap, it will give you PlaneItem pointers,
+// not Sprite pointers.  If you're sure that the PlaneMap contains
+// only sprites, then you can use static_cast to convert those
+// PlaneItem pointers to Sprite pointers.  Sadly, there's no simple
+// way to avoid the casting.
+//
+// MEMORY MANAGEMENT
+//
+// The PlaneMap does not own the PlaneItems.  You need to create,
+// destroy, and manage the PlaneItems yourself.
+//
+
+#ifndef PLANEMAP_HPP
+#define PLANEMAP_HPP
+
+#include <cstdint>
+#include <vector>
+#include <map>
+
+class PlaneMap;
+
+class PlaneItem {
+    friend class PlaneMap;
+private:
+    PlaneMap *grid_;
+    std::string plane_;
+    double x_, y_, z_;
+public:
+    PlaneItem();
+    ~PlaneItem();
+
+    const std::string &plane() const { return plane_; }
+    const double x() const { return x_; }
+    const double y() const { return y_; }
+    const double z() const { return z_; }
+
+    void use_map(PlaneMap *map);
+    void set_pos(const std::string &plane, double x, double y, double z);
+};
+
+class PlaneMap {
+    friend class PlaneItem;
+    friend int cunittests_planemap(lua_State *L);
+public:
+    using Elt = PlaneItem *;
+    using EltVec = std::vector<Elt>;
+private:
+    using Plane = std::map<int64_t, EltVec>;
+    std::map<std::string, Plane> planes_;
+    void remove(const std::string &plane, int64_t cell, PlaneItem *client);
+    void insert(const std::string &plane, int64_t cell, PlaneItem *client);
+private:
+    // These functions are only used in unit tests.
+    EltVec get_cell(const std::string &plane, int64_t cell) const;
+    int total_cells() const;
+    void clear() { planes_.clear(); }
+public:
+    PlaneMap();
+    ~PlaneMap();
+    EltVec scan_radius(const std::string &plane, double x, double y, double radius) const;
+};
+
+#endif // PLANEMAP_HPP
+
+