From 0e626380474cf9f94abaeff769cc3d8bbbe2746b Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Sun, 6 Jun 2010 18:14:48 +0100
Subject: [PATCH] Start adding Lua VM inside game

---
 CMakeLists.txt   |  3 +-
 include/ILua.hpp | 34 +++++++++++++++++++
 src/LuaWrap.cpp  | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/Main.cpp     |  4 +++
 4 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 include/ILua.hpp
 create mode 100644 src/LuaWrap.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 91b4d70..6f2f9be 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,6 +24,7 @@ find_package (SDL_image REQUIRED)
 find_package (OpenGL REQUIRED)
 find_package (GLEW REQUIRED)
 find_package (Boost 1.37 REQUIRED COMPONENTS filesystem signals program_options) 
+find_package (Lua51 REQUIRED)
 
 if (NOT WIN32)
   include (FindPkgConfig)
@@ -53,7 +54,7 @@ add_executable (${PROJECT_NAME} WIN32 ${folder_source})
 
 target_link_libraries (${PROJECT_NAME} ${SDL_LIBRARY} ${SDLIMAGE_LIBRARY}
   ${OPENGL_LIBRARY} ${XERCES_LIBRARIES} ${Boost_LIBRARIES}
-  ${FREETYPE_LIBRARIES} ${GLEW_LIBRARY})
+  ${FREETYPE_LIBRARIES} ${GLEW_LIBRARY} ${LUA51_LIBRARIES})
 
 # Profiling
 if (PROFILE)
diff --git a/include/ILua.hpp b/include/ILua.hpp
new file mode 100644
index 0000000..df1710a
--- /dev/null
+++ b/include/ILua.hpp
@@ -0,0 +1,34 @@
+//
+//  Copyright (C) 2010  Nick Gasson
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INC_ILUA_HPP
+#define INC_ILUA_HPP
+
+#include "Platform.hpp"
+
+// Wrapper class for Lua
+struct ILua {
+   virtual ~ILua() {}
+
+   virtual void eval(const string& code) = 0;
+};
+
+typedef shared_ptr<ILua> ILuaPtr;
+
+ILuaPtr getLua();
+
+#endif
diff --git a/src/LuaWrap.cpp b/src/LuaWrap.cpp
new file mode 100644
index 0000000..73b6a28
--- /dev/null
+++ b/src/LuaWrap.cpp
@@ -0,0 +1,85 @@
+//
+//  Copyright (C) 2010  Nick Gasson
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "ILua.hpp"
+#include "ILogger.hpp"
+
+#include <stdexcept>
+
+extern "C" {
+#include <lua5.1/lua.h>
+#include <lua5.1/lauxlib.h>
+}
+
+class LuaWrap : public ILua {
+public:
+   LuaWrap();
+   ~LuaWrap();
+
+   void eval(const string& code);
+private:
+   lua_State* luaVM;
+};
+
+LuaWrap::LuaWrap()
+{
+   log() << "Creating Lua VM";
+   
+   if ((luaVM = lua_open()) == NULL) 
+      throw runtime_error("Failed to initialise Lua");
+}
+
+LuaWrap::~LuaWrap()
+{
+   lua_close(luaVM);
+}
+
+void LuaWrap::eval(const string& code)
+{
+   int result = luaL_loadstring(luaVM, code.c_str());
+   
+   switch (result) {
+   case LUA_ERRSYNTAX:
+      error() << "Lua syntax error";
+      return;
+   case LUA_ERRMEM:
+      error() << "Out of Lua memory";
+      return;
+   }
+
+   result = lua_pcall(luaVM, 0, 0, 0);
+   switch (result) {
+   case LUA_ERRRUN:
+   case LUA_ERRERR:
+      error() << "Lua: " << lua_tolstring(luaVM, -1, NULL);
+      lua_pop(luaVM, 1);
+      break;
+   case LUA_ERRMEM:
+      error() << "Lua out of memory!";
+      break;
+   }
+}
+
+ILuaPtr getLua()
+{
+   static ILuaPtr lua;
+
+   if (!lua)
+      lua = ILuaPtr(new LuaWrap);
+
+   return lua;
+}
diff --git a/src/Main.cpp b/src/Main.cpp
index 3092b46..9d43fa2 100644
--- a/src/Main.cpp
+++ b/src/Main.cpp
@@ -20,6 +20,7 @@
 #include "GameScreens.hpp"
 #include "IResource.hpp"
 #include "IConfig.hpp"
+#include "ILua.hpp"
 
 #include <stdexcept>
 #include <iostream>
@@ -103,6 +104,9 @@ int main(int argc, char** argv)
       IConfigPtr cfg = getConfig();
       
       ::window = makeSDLWindow();
+
+      ILuaPtr lua = getLua();
+      lua->eval("debug(\"hello\")");
       
       IScreenPtr screen;
       if (::action == "edit") {
-- 
2.39.2