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[rbdr/pico-engine] / LuaScript.cpp

// ---------------------------------------------------------------------------\r
// FILE NAME            : LuaScript.cpp\r
// ---------------------------------------------------------------------------\r
// DESCRIPTION :\r
//\r
// Simple debugging routines\r
// \r
// ---------------------------------------------------------------------------\r
// VERSION              : 1.00\r
// DATE                 : 1-Sep-2005\r
// AUTHOR               : Richard Shephard\r
// ---------------------------------------------------------------------------\r
// LIBRARY INCLUDE FILES\r
#include <assert.h>\r
#include "luainc.h"\r
#include "luascript.h"\r
#include "luarestorestack.h"\r
#include "luathis.h"\r
// ---------------------------------------------------------------------------\r
\r
#define BEGIN_LUA_CHECK(vm)   lua_State *state = (lua_State *) vm; \\r
                              if (vm.Ok ()) { \r
#define END_LUA_CHECK         }\r
\r
\r
//============================================================================\r
// int LuaCallback\r
//---------------------------------------------------------------------------\r
// Lua C-API calling that figures out which object to hand over to\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// lua         IN       State variable\r
//\r
// Return\r
// ------\r
// Number of return varaibles on the stack\r
//\r
// Comments\r
// --------\r
// This is the function lua calls for each C-Function that is\r
// registered with lua. At the time of registering the function\r
// with lua, we make lua record the method "number" so we can\r
// know what method was actually called. The lua stack is the\r
// following structure:\r
// 0: 'this' (table)\r
// 1 - ...: parameters passed in\r
//\r
//============================================================================\r
static int LuaCallback (lua_State *lua)\r
{\r
   // Locate the psudo-index for the function number\r
   int iNumberIdx = lua_upvalueindex (1);\r
   int nRetsOnStack = 0;\r
\r
   bool fSuccess = false;\r
\r
   // Check for the "this" table\r
   if (lua_istable (lua, 1))\r
   {\r
      // Found the "this" table. The object pointer is at the index 0\r
      lua_rawgeti (lua, 1, 0);\r
      \r
      if (lua_islightuserdata (lua, -1))\r
      {\r
         // Found the pointer, need to cast it\r
         CLuaScript *pThis = (CLuaScript *) lua_touserdata (lua, -1);\r
\r
         // Get the method index\r
         int iMethodIdx = (int) lua_tonumber (lua, iNumberIdx);\r
\r
         // Check that the method is correct index\r
         assert (!(iMethodIdx > pThis->methods ()));\r
\r
         // Reformat the stack so our parameters are correct\r
         // Clean up the "this" table\r
         lua_remove (lua, 1);\r
         // Clean up the pThis pointer\r
         lua_remove (lua, -1);\r
\r
         // Call the class\r
         nRetsOnStack = pThis->ScriptCalling (pThis->vm (), iMethodIdx);\r
\r
         fSuccess = true;\r
      }\r
   }\r
\r
   if (fSuccess == false)\r
   {\r
      lua_pushstring (lua, "LuaCallback -> Failed to call the class function");\r
      lua_error (lua);\r
   }\r
\r
   // Number of return variables\r
   return nRetsOnStack;\r
}\r
\r
\r
//============================================================================\r
// CLuaScript::CLuaScript\r
//---------------------------------------------------------------------------\r
// Constructor. Sets up the lua stack and the "this" table\r
//\r
// Parameter            Dir      Description\r
// ---------            ---      -----------\r
// CLuaVirtualMachine   IN       VM to run on\r
//\r
// Return\r
// ------\r
// None.\r
//\r
//============================================================================\r
CLuaScript::CLuaScript (CLuaVirtualMachine& vm)\r
 : m_vm (vm), m_nMethods (0), m_iThisRef (0), m_nArgs (0)\r
{\r
   BEGIN_LUA_CHECK (vm)\r
      // Create a reference to the "this" table. Each reference is unique\r
      lua_newtable (state);\r
      m_iThisRef = luaL_ref (state, LUA_REGISTRYINDEX);\r
\r
      // Save the "this" table to index 0 of the "this" table\r
      CLuaRestoreStack rs (vm);\r
      lua_rawgeti (state, LUA_REGISTRYINDEX, m_iThisRef);\r
      lua_pushlightuserdata (state, (void *) this);\r
      lua_rawseti (state, -2, 0);\r
   END_LUA_CHECK\r
}\r
\r
//============================================================================\r
// CLuaScript::~CLuaScript\r
//---------------------------------------------------------------------------\r
// Destructor\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// None.\r
//\r
// Return\r
// ------\r
// None.\r
//\r
//============================================================================\r
CLuaScript::~CLuaScript (void)\r
{\r
   CLuaRestoreStack rs (m_vm);\r
\r
   BEGIN_LUA_CHECK (m_vm)\r
      // Get the reference "this" table\r
      lua_rawgeti (state, LUA_REGISTRYINDEX, m_iThisRef);\r
\r
      // Clear index 0\r
      lua_pushnil (state);\r
      lua_rawseti (state, -2, 0);\r
   END_LUA_CHECK\r
	\r
}\r
\r
//============================================================================\r
// bool CLuaScript::CompileBuffer\r
//---------------------------------------------------------------------------\r
// Compiles a given buffer\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// pbBuffer    IN       Data buffer\r
// szLen       IN       Length of buffer\r
//\r
// Return\r
// ------\r
// Success\r
//\r
//============================================================================\r
bool CLuaScript::CompileBuffer (unsigned char *pbBuffer, size_t szLen)\r
{\r
   assert (pbBuffer != NULL && "CLuaScript::CompileBuffer ->  pbBuffer == NULL");\r
   assert (szLen != 0 && "CLuaScript::CompileBuffer -> szLen == 0");\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   // Make sure we have the correct "this" table\r
   CLuaThis luaThis (m_vm, m_iThisRef);\r
\r
   return m_vm.RunBuffer (pbBuffer, szLen);\r
}\r
\r
//============================================================================\r
// bool CLuaScript::CompileBuffer\r
//---------------------------------------------------------------------------\r
// Compiles a given file\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// strFilename IN       File name to compile\r
//\r
// Return\r
// ------\r
// Success\r
//\r
//============================================================================\r
bool CLuaScript::CompileFile (const char *strFilename)\r
{\r
   assert (strFilename != NULL && "CLuaScript::CompileFile -> strFilename == NULL");\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   // Make sure we have the correct "this" table\r
   CLuaThis luaThis (m_vm, m_iThisRef);\r
\r
   return m_vm.RunFile (strFilename);\r
}\r
\r
//============================================================================\r
// int CLuaScript::RegisterFunction\r
//---------------------------------------------------------------------------\r
// Registers a function with Lua\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// strFuncName IN       Function name\r
//\r
// Return\r
// ------\r
// Success\r
//\r
//============================================================================\r
int CLuaScript::RegisterFunction (const char *strFuncName)\r
{\r
   assert (strFuncName != NULL && "CLuaScript::RegisterFunction -> strFuncName == NULL");\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   int iMethodIdx = -1;\r
\r
   CLuaRestoreStack rs (m_vm);\r
\r
   BEGIN_LUA_CHECK (m_vm)\r
      iMethodIdx = ++m_nMethods;\r
\r
      // Register a function with the lua script. Added it to the "this" table\r
      lua_rawgeti (state, LUA_REGISTRYINDEX, m_iThisRef);\r
\r
      // Push the function and parameters\r
      lua_pushstring (state, strFuncName);\r
      lua_pushnumber (state, (lua_Number) iMethodIdx);\r
      lua_pushcclosure (state, LuaCallback, 1);\r
      lua_settable (state, -3);\r
\r
   END_LUA_CHECK\r
\r
   return iMethodIdx;\r
}\r
\r
//============================================================================\r
// bool CLuaScript::SelectScriptFunction\r
//---------------------------------------------------------------------------\r
// Selects a script function to run\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// strFuncName IN       Function name\r
//\r
// Return\r
// ------\r
// Success\r
//\r
//============================================================================\r
bool CLuaScript::SelectScriptFunction (const char *strFuncName)\r
{\r
   assert (strFuncName != NULL && "CLuaScript::SelectScriptFunction -> strFuncName == NULL");\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   bool fSuccess = true;\r
\r
   BEGIN_LUA_CHECK (m_vm)\r
      // Look up function name\r
      lua_rawgeti (state, LUA_REGISTRYINDEX, m_iThisRef);\r
      lua_pushstring (state, strFuncName);\r
      lua_rawget (state, -2);\r
      lua_remove (state, -2);\r
\r
      // Put the "this" table back\r
      lua_rawgeti (state, LUA_REGISTRYINDEX, m_iThisRef);\r
\r
      // Check that we have a valid function\r
      if (!lua_isfunction (state, -2))\r
      {\r
         fSuccess = false;\r
         lua_pop (state, 2);\r
      }\r
      else\r
      {\r
         m_nArgs = 0;\r
         m_strFunctionName = strFuncName;\r
      }\r
   END_LUA_CHECK\r
   \r
   return fSuccess;\r
}\r
\r
//============================================================================\r
// bool CLuaScript::ScriptHasFunction\r
//---------------------------------------------------------------------------\r
// Checks to see if a function exists\r
//\r
// Parameter      Dir      Description\r
// ---------      ---      -----------\r
// strScriptName  IN       Function name\r
//\r
// Return\r
// ------\r
// Success\r
//\r
//============================================================================\r
bool CLuaScript::ScriptHasFunction (const char *strScriptName)\r
{\r
   assert (strScriptName != NULL && "CLuaScript::ScriptHasFunction -> strScriptName == NULL");\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   CLuaRestoreStack rs (m_vm);\r
\r
   bool fFoundFunc = false;\r
\r
   BEGIN_LUA_CHECK (m_vm)\r
      lua_rawgeti (state, LUA_REGISTRYINDEX, m_iThisRef);\r
      lua_pushstring (state, strScriptName);\r
      lua_rawget (state, -2);\r
      lua_remove (state, -2);\r
\r
      if (lua_isfunction (state, -1))\r
      {\r
         fFoundFunc = true;\r
      }\r
   END_LUA_CHECK\r
\r
   return fFoundFunc;\r
}\r
\r
//============================================================================\r
// void CLuaScript::AddParam\r
//---------------------------------------------------------------------------\r
// Adds a parameter to the parameter list\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// string      IN       string param\r
//\r
// Return\r
// ------\r
// None.\r
//\r
//============================================================================\r
void CLuaScript::AddParam (char *string)\r
{\r
   assert (string != NULL && "CLuaScript::AddParam -> string == NULL");\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   BEGIN_LUA_CHECK (m_vm)\r
      lua_pushstring (state, string);\r
      ++m_nArgs;\r
   END_LUA_CHECK\r
}\r
\r
//============================================================================\r
// void CLuaScript::AddParam\r
//---------------------------------------------------------------------------\r
// Adds a parameter to the parameter list\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// iInt        IN       int param\r
//\r
// Return\r
// ------\r
// None.\r
//\r
//============================================================================\r
void CLuaScript::AddParam (int iInt)\r
{\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   BEGIN_LUA_CHECK (m_vm)\r
      lua_pushnumber (state, (lua_Number) iInt);\r
      ++m_nArgs;\r
   END_LUA_CHECK\r
}\r
\r
//============================================================================\r
// void CLuaScript::AddParam\r
//---------------------------------------------------------------------------\r
// Adds a parameter to the parameter list\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// fFloat      IN       float param\r
//\r
// Return\r
// ------\r
// None.\r
//\r
//============================================================================\r
void CLuaScript::AddParam (float fFloat)\r
{\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   BEGIN_LUA_CHECK (m_vm)\r
      lua_pushnumber (state, (lua_Number) fFloat);\r
      ++m_nArgs;\r
   END_LUA_CHECK\r
}\r
\r
//============================================================================\r
// bool CLuaScript::Go\r
//---------------------------------------------------------------------------\r
// Runs the selected script function\r
//\r
// Parameter   Dir      Description\r
// ---------   ---      -----------\r
// nReturns    IN       Number of expected returns\r
//\r
// Return\r
// ------\r
// None.\r
//\r
//============================================================================\r
bool CLuaScript::Go (int nReturns /* = 0 */)\r
{\r
   assert (m_vm.Ok () && "VM Not OK");\r
\r
   // At this point there should be a parameters and a function on the\r
   // Lua stack. Each function get a "this" parameter as default and is\r
   // pushed onto the stack when the method is selected\r
\r
   bool fSuccess = m_vm.CallFunction (m_nArgs + 1, nReturns);\r
\r
   if (fSuccess == true && nReturns > 0)\r
   {\r
      // Check for returns\r
      HandleReturns (m_vm, m_strFunctionName);\r
      lua_pop ((lua_State *) m_vm, nReturns);\r
   }\r
\r
   return fSuccess;\r
}