RmlUi/Samples/lua_invaders/src/LuaInterface.cpp

#include "LuaInterface.h"
#include "ElementGameInstancer.h"
#include "Game.h"
#include "GameDetails.h"
#include "HighScores.h"
#include <RmlUi/Core/Factory.h>
#include <RmlUi/Core/Log.h>
#include <RmlUi/Core/Types.h>
#include <RmlUi/Lua/IncludeLua.h>
#include <RmlUi/Lua/LuaType.h>
#include <RmlUi_Backend.h>
#include <Shell.h>

/*
 * We have to create the binding ourselves, and these are the functions that will be
 * called. It has to match the function signature of int (*ftnptr)(lua_State*).
 */
int GameShutdown(lua_State* L);
int GameSetPaused(lua_State* L);
int GameSetDifficulty(lua_State* L);
int GameSetDefenderColour(lua_State* L);
int GameSubmitHighScore(lua_State* L);
int GameSetHighScoreName(lua_State* L);

static ElementGameInstancer game_instancer;

void LuaInterface::Initialise(lua_State* L)
{
	InitGame(L);
	Rml::Factory::RegisterNodeInstancer("game", &game_instancer);
}

void LuaInterface::InitGame(lua_State* L)
{
	luaL_dostring(L, "Game = Game or {}"); // doing this in Lua because it would be 10+ lines in C++
	lua_getglobal(L, "Game");
	int game = lua_gettop(L);

	if (lua_isnil(L, game))
	{
		Rml::Log::Message(Rml::Log::LT_ERROR, "Error creating the Game table from C++ in LuaInterface::InitGame");
		return;
	}

	// this can be done in a loop similar to the implementation of LuaType::_regfunctions, but I am
	// defining them explicitly so that there is no black magic
	lua_pushcfunction(L, GameShutdown);
	lua_setfield(L, game, "Shutdown");

	lua_pushcfunction(L, GameSetPaused);
	lua_setfield(L, game, "SetPaused");

	lua_pushcfunction(L, GameSetDifficulty);
	lua_setfield(L, game, "SetDifficulty");

	lua_pushcfunction(L, GameSetDefenderColour);
	lua_setfield(L, game, "SetDefenderColour");

	lua_pushcfunction(L, GameSubmitHighScore);
	lua_setfield(L, game, "SubmitHighScore");

	lua_pushcfunction(L, GameSetHighScoreName);
	lua_setfield(L, game, "SetHighScoreName");

	lua_newtable(L);                       // table, Game
	lua_pushinteger(L, GameDetails::HARD); // int,table,Game
	lua_setfield(L, -2, "HARD");           // table,Game

	lua_pushinteger(L, GameDetails::EASY); // int,table,Game
	lua_setfield(L, -2, "EASY");           // table,Game

	lua_setfield(L, game, "difficulty");   // Game

	lua_pop(L, 1);                         // pop Game
}

int GameShutdown(lua_State* /*L*/)
{
	Backend::RequestExit();
	return 0;
}

int GameSetPaused(lua_State* L)
{
	bool paused = RMLUI_CHECK_BOOL(L, 1); // RMLUI_CHECK_BOOL defined in LuaType.h
	GameDetails::SetPaused(paused);
	return 0;
}

int GameSetDifficulty(lua_State* L)
{
	int difficulty = (int)luaL_checkinteger(L, 1);
	GameDetails::SetDifficulty((GameDetails::Difficulty)difficulty);
	return 0;
}

int GameSetDefenderColour(lua_State* L)
{
	Rml::Colourb* colour = Rml::Lua::LuaType<Rml::Colourb>::check(L, 1);
	GameDetails::SetDefenderColour(*colour);
	return 0;
}

int GameSubmitHighScore(lua_State* /*L*/)
{
	int score = GameDetails::GetScore();
	if (score > 0)
	{
		// Submit the score the player just got to the high scores chart.
		HighScores::SubmitScore(GameDetails::GetDefenderColour(), GameDetails::GetWave(), GameDetails::GetScore());
		// Reset the score so the chart won't get confused next time we enter.
		GameDetails::ResetScore();
	}
	return 0;
}

int GameSetHighScoreName(lua_State* L)
{
	const char* name = luaL_checkstring(L, 1);
	HighScores::SubmitName(name);
	return 0;
}