sol2_coro.cpp

#include <Siv3D.hpp>
#include <memory>

// Lua 5.2.x (need 'lua52.dll' at runtime)
#include <lua.hpp>
#pragma comment(lib, "lua52.lib")

// Sol 2.14
#include <sol.hpp>


struct Colorful
{
	int frame = 0;
	Color color = Palette::White;
	sol::thread thread;
	sol::coroutine coro;

	Colorful(sol::state& lua)
	{
		thread = sol::thread::create(lua.lua_state());
		coro = thread.state()["colorful_update"];
	}

	void update()
	{
		if (coro.runnable())
		{
			coro(this);

			PutText(L"coroutine running");
		}
		else
		{
			PutText(L"coroutine finished");
		}

		RectF(200, 200).setCenter(Window::Center()).draw(color);

		++frame;
	}
};


void Main()
{
	// Init Sol

	sol::state lua;
	lua.open_libraries(sol::lib::base, sol::lib::package, sol::lib::math, sol::lib::coroutine);


	// Register classes

	lua.new_usertype<Color>("Color",
		"set", &Color::set,
		"r", sol::property([](Color& c) { return c.r; }, [](Color& c, int r) { c.r = r; }),
		"g", sol::property([](Color& c) { return c.g; }, [](Color& c, int g) { c.g = g; }),
		"b", sol::property([](Color& c) { return c.b; }, [](Color& c, int b) { c.b = b; }),
		"a", sol::property([](Color& c) { return c.a; }, [](Color& c, int a) { c.a = a; })
		);

	lua.new_usertype<Colorful>("Colorful",
		"frame", &Colorful::frame,
		"color", &Colorful::color
		);


	// Define 'Colorful' coroutine

	lua.script(
		"function colorful_update(c)\n"
		"	-- Blink white\n"
		"	for i=0, 120 do\n"
		"		local v = 255 * i / 120\n"
		"		c.color:set(v, v, v, 128 + 127 * (math.floor(i / 2) % 2))\n"
		"		coroutine.yield()\n"
		"	end\n"
		""
		"	-- White to orange\n"
		"	for i=0, 100 do\n"
		"		c.color:set(255, 255 - 127 * i / 100, 255 - 255 * i / 100, 255)\n"
		"		coroutine.yield()\n"
		"	end\n"
		""
		"	-- Orange to green\n"
		"	for i=0, 60 do\n"
		"		c.color:set(255 - 255 * i / 60, 128 + 112 * i / 60, 0, 255)\n"
		"		coroutine.yield()\n"
		"	end\n"
		""
		"	return 0\n"
		"end"
	);


	Colorful colorful(lua);

	while (System::Update())
	{
		colorful.update();
	}
}