Scene changing with ham::SceneManager

siv3d_scene.cpp

#include <Siv3D.hpp>
#include <HamFramework.hpp>

// こちらで詳しい解説がされています:
// http://qiita.com/hamukun8686/items/4620d630b538c78a6e02

enum class SceneType
{
    Empty,
    Title,
    Main,
};

struct GameData
{
    void Fade(double t, bool fadeIn)
    {
        Graphics2D::SetStencilState(StencilState::Replace);
        Graphics2D::SetStencilValue(1);

        Circle(Window::Center(), (fadeIn ? t : 1 - t) * (Window::ClientRect().w) / 2.0 * 1.3).draw();

        Graphics2D::SetStencilState(StencilState::Test(StencilFunc::NotEqual));

        Window::ClientRect().draw(Palette::Black);

        Graphics2D::SetStencilState(StencilState::Default);
    }
};

using SceneMgr = SceneManager<SceneType, GameData>;

struct SceneEmpty : SceneMgr::Scene
{
    void update() override {}
    
    void draw() const override
    {
        Window::ClientRect().draw(Palette::Black);
    }

    void updateFadeIn(double t) override
    {
        // 即タイトルシーンへ
        changeScene(SceneType::Title, 750, true);
    }
};

struct SceneTitle : SceneMgr::Scene
{
    void update() override
    {
        if (Input::MouseL.clicked)
        {
            changeScene(SceneType::Main, 750);
        }
    }

    void draw() const override
    {
        Window::ClientRect().draw(Palette::Royalblue);

        FontAsset(L"font")(L"TITLE").drawCenter(Window::Center(), Palette::White);
    }
};

struct SceneMain : SceneMgr::Scene
{
    void update() override
    {
        if (Input::MouseL.clicked)
        {
            changeScene(SceneType::Title, 750);
        }
    }

    void draw() const override
    {
        Window::ClientRect().draw(Palette::Palevioletred);

        FontAsset(L"font")(L"MAIN GAME SCENE").drawCenter(Window::Center(), Palette::White);
    }

    void drawFadeIn(double t) const override
    {
        draw();
        m_data->Fade(t, true);
    }

    void drawFadeOut(double t) const override
    {
        draw();
        m_data->Fade(t, false);
    }
};

void Main()
{
    Window::Resize(640, 480);

    Graphics::SetBackground(Palette::Black);

    FontAsset::Register(L"font", 40, Typeface::Bold);

    SceneMgr sceneMgr;

    sceneMgr.add<SceneEmpty>(SceneType::Empty);
    sceneMgr.add<SceneTitle>(SceneType::Title);
    sceneMgr.add<SceneMain>(SceneType::Main);

    while (System::Update())
    {
        if (!sceneMgr.updateAndDraw())
        {
            break;
        }
    }
}