SceneManager.hpp

/*
 * Rhythm Run for Nintendo 3DS
 * Lauren Kelly, 2021
 */

#pragma once

#include <3ds.h>
#include <stdint.h>

#include <memory>
#include <unordered_map>

#include "RenderWindow.hpp"
#include "Scene.hpp"

/// Finite state machine to handle scene management
class SceneManager {
public:
    SceneManager();

    // Pass through to active scene
    inline void processInput()
    {
        if (currentScene)
            currentScene->processInput();
    };
    inline void update(float a_timeDelta)
    {
        if (currentScene)
            currentScene->update(a_timeDelta);
    };
    inline void lateUpdate(float a_timeDelta)
    {
        if (currentScene)
            currentScene->lateUpdate(a_timeDelta);
        if (shouldShutdown() && currentScene->canQuit())
            quit();
    };

    inline void draw(RenderWindow& a_renderWindowUpper, RenderWindow& a_renderWindowLower)
    {
        if (currentScene && !shouldShutdown())
            currentScene->draw(a_renderWindowUpper, a_renderWindowLower);
    };

    // Add scene to the state machine, returning its ID
    unsigned int addScene(std::shared_ptr<Scene> a_scene);
    // Transition focus to scene
    bool switchFocusTo(unsigned int a_sceneId);
    // Remove scene from the state machine
    void removeScene(unsigned int a_sceneId);

    /// Set shutdown flag
    void shutdown() { shutdownFlag = true; }

    /// is shutdown flag set?
    bool shouldShutdown() { return shutdownFlag; }

    /// Set quit flag
    void quit()
    {
        shutdownFlag = true;
        quitFlag = true;
    }

    /// is quit flag set?
    bool shouldQuit() { return quitFlag; }

    /// Stores all scenes
    std::unordered_map<unsigned int, std::shared_ptr<Scene>> scenes;

private:
    /// Stores a reference to the current scene
    std::shared_ptr<Scene> currentScene;
    /// Stores the current scene ID, incremented whenever a scene is added
    unsigned int sceneCounter;
    /// should scenes wind down?
    bool shutdownFlag;
    /// are we ready to quit?
    bool quitFlag;
};