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