src/script.h

   1 /******************************
   2 ** Tsunagari Tile Engine     **
   3 ** script.h                  **
   4 ** Copyright 2011 OmegaSDG   **
   5 ******************************/
   6
   7 #ifndef SCRIPT_H
   8 #define SCRIPT_H
   9
  10 #include <string>
  11
  12 #include <lua.hpp>
  13
  14 class Entity;
  15 class Resourcer;
  16
  17 //! Compile and execute Lua code at runtime.
  18 /*!
  19         A Script represents a self-contained Lua state. It might have
  20         variables, functions, statements, and expressions, and can be executed.
  21         Each Script lives in a separate memory space and cannot directly
  22         access or call other Scripts.
  23
  24         On their own, Scripts cannot change anything in a game. Instead, you
  25         must bind C functions that they can call. These C functions can access
  26         the C++ objects in the game. You might bind a function that makes a
  27         player jump, or that returns the distance to the nearest town.  You can
  28         also bind variables that a script can access.
  29
  30         Scripts use Lua 5.1
  31 */
  32 class Script
  33 {
  34 public:
  35         //! Create a new Lua state. The state is destroyed with the death of
  36         //this object.
  37         Script();
  38
  39         //! If we already have a Lua state, wrap around it. The state is not
  40         //destroyed with the death of this object.
  41         Script(lua_State* L);
  42
  43         //! Destroy the Lua state if we own it.
  44         ~Script();
  45
  46
  47         //! Bind a C function to a global variable in Lua.
  48         void bindGlobalFn(const char* name, lua_CFunction fn);
  49
  50         //! Bind a C function to a table index. In Lua: "table.index = fn"
  51         void bindObjFn(const char* table, const char* index, lua_CFunction fn);
  52
  53         //! Set a global integer variable in Lua.
  54         void bindInt(const char* name, lua_Integer i);
  55
  56
  57         //! Create a global table with specified name which represents an Entity.
  58         void bindEntity(const char* name, Entity* entity);
  59
  60         //! Get the Entity object from a table in the Lua stack at a specific
  61         //position.
  62         Entity* getEntity(int pos);
  63
  64
  65         //! Compile and run a script, keeping all existing bindings intact.
  66         void run(Resourcer* rc, const char* fn);
  67
  68 private:
  69         //! Did we create our state, or are we borrowing it from another Script
  70         //object?
  71         bool ownState;
  72
  73         //! Everything necessary to compile and run a Lua script.
  74         lua_State* L; // TODO: change to shared_ptr ?
  75 };
  76
  77 #endif
  78