LuaGame little refactoring

1. All variables that are not going to change their value are marked constant;
2. Adds "return luaL_error", like specified in "TODO's";
3. All instances where "return 0" was called after "luaL_error" changed simply to "return luaL_error(...)".

src/lua/LuaGame.cpp

@@ -61,13 +61,12 @@
 static int l_game_start_game(lua_State *l)
 {
  if (Pi::game) {
- luaL_error(l, "can't start a new game while a game is already running");
- return 0;
+ return luaL_error(l, "can't start a new game while a game is already running");
  }
 
- auto path = LuaPull<SystemPath>(l, 1);
- auto time = LuaPull<double>(l, 2);
- auto shipType = LuaPull<const char*>(l, 3);
+ const auto path = LuaPull<SystemPath>(l, 1);
+ const auto time = LuaPull<double>(l, 2);
+ const auto shipType = LuaPull<const char*>(l, 3);
 
  Pi::StartGame(new Game(path, time, shipType));
  return 0;
@@ -446,7 +445,7 @@ static int l_game_attr_paused(lua_State *l)
  if (!Pi::game)
  lua_pushboolean(l, 1);
  else
- lua_pushboolean(l, Pi::game->IsPaused() ? 1 : 0);
+ lua_pushboolean(l, Pi::game->IsPaused());
  return 1;
 }
 
@@ -529,7 +528,7 @@ static int l_game_switch_view(lua_State *l)
  return 0;
 }
 
-static void pushTimeAccel(lua_State *l, Game::TimeAccel accel)
+static int pushTimeAccel(lua_State *l, const Game::TimeAccel accel)
 {
  switch (accel) {
  case Game::TIMEACCEL_PAUSED: lua_pushstring(l, "paused"); break;
@@ -539,28 +538,28 @@ static void pushTimeAccel(lua_State *l, Game::TimeAccel accel)
  case Game::TIMEACCEL_1000X: lua_pushstring(l, "1000x"); break;
  case Game::TIMEACCEL_10000X: lua_pushstring(l, "10000x"); break;
  case Game::TIMEACCEL_HYPERSPACE: lua_pushstring(l, "hyperspace"); break;
- default: break; // TODO error
+ default:
+ return luaL_error(l, "TimeAccel value of \"%d\" is outside of Game::TimeAccel enum", accel);
  }
+ return 1;
 }
 
 static int l_game_get_time_acceleration(lua_State *l)
 {
- Game::TimeAccel accel = Pi::game->GetTimeAccel();
- pushTimeAccel(l, accel);
- return 1;
+ const Game::TimeAccel accel = Pi::game->GetTimeAccel();
+ return pushTimeAccel(l, accel);
 }
 
 static int l_game_get_requested_time_acceleration(lua_State *l)
 {
- Game::TimeAccel accel = Pi::game->GetRequestedTimeAccel();
- pushTimeAccel(l, accel);
- return 1;
+ const Game::TimeAccel accel = Pi::game->GetRequestedTimeAccel();
+ return pushTimeAccel(l, accel);
 }
 
 static int l_game_set_time_acceleration(lua_State *l)
 {
- std::string accel = LuaPull<std::string>(l, 1);
- bool force = LuaPull<bool>(l, 2);
+ const std::string accel = LuaPull<std::string>(l, 1);
+ const bool force = LuaPull<bool>(l, 2);
  Game::TimeAccel a = Game::TIMEACCEL_PAUSED;
  if (!accel.compare("paused"))
  a = Game::TIMEACCEL_PAUSED;
@@ -576,14 +575,15 @@ static int l_game_set_time_acceleration(lua_State *l)
  a = Game::TIMEACCEL_10000X;
  else if (!accel.compare("hyperspace"))
  a = Game::TIMEACCEL_HYPERSPACE;
- // else TODO error
+ else
+ return luaL_error(l, "Unknown time acceleration %s", accel.c_str());
  Pi::game->RequestTimeAccel(a, force);
  return 0;
 }
 
 static int l_game_get_date_time(lua_State *l)
 {
- Time::DateTime t(Pi::game->GetTime());
+ const Time::DateTime t(Pi::game->GetTime());
  int year, month, day, hour, minute, second;
  t.GetDateParts(&year, &month, &day);
  t.GetTimeParts(&hour, &minute, &second);
@@ -600,7 +600,7 @@ static int l_game_set_view(lua_State *l)
 {
  if (!Pi::game)
  return luaL_error(l, "can't set view when no game is running");
- std::string target = luaL_checkstring(l, 1);
+ const std::string target = luaL_checkstring(l, 1);
  if (!target.compare("world")) {
  Pi::SetView(Pi::game->GetWorldView());
  } else if (!target.compare("space_station")) {
@@ -614,7 +614,7 @@ static int l_game_set_view(lua_State *l)
  } else if (!target.compare("system")) {
  Pi::SetView(Pi::game->GetSystemView());
  } else {
- // TODO else error
+ return luaL_error(l, "Unknown view %s", target.c_str());
  }
  return 0;
 }
@@ -633,7 +633,7 @@ static int l_game_get_world_cam_type(lua_State *l)
 
 static int l_game_set_world_cam_type(lua_State *l)
 {
- std::string cam = luaL_checkstring(l, 1);
+ const std::string cam = luaL_checkstring(l, 1);
  if (!cam.compare("internal"))
  Pi::game->GetWorldView()->shipView->SetCamType(ShipViewController::CAM_INTERNAL);
  else if (!cam.compare("external"))
@@ -642,9 +642,8 @@ static int l_game_set_world_cam_type(lua_State *l)
  Pi::game->GetWorldView()->shipView->SetCamType(ShipViewController::CAM_SIDEREAL);
  else if (!cam.compare("flyby"))
  Pi::game->GetWorldView()->shipView->SetCamType(ShipViewController::CAM_FLYBY);
- else {
- // TODO else error
- }
+ else
+ return luaL_error(l, "Unknown world cam type %s", cam.c_str());
  return 0;
 }
 
@@ -656,8 +655,8 @@ static int l_game_get_hyperspace_travelled_percentage(lua_State *l)
 
 static int l_game_get_parts_from_date_time(lua_State *l)
 {
- double time = LuaPull<double>(l, 1);
- Time::DateTime t(time);
+ const double time = LuaPull<double>(l, 1);
+ const Time::DateTime t(time);
  int year, month, day, hour, minute, second;
  t.GetDateParts(&year, &month, &day);
  t.GetTimeParts(&hour, &minute, &second);