{{:raylib:jsonsaveandload.png?600|JSON Save and Load}}

===== Raylib Example ===== 

[[https://github.com/raysan5/raylib/blob/master/examples/core/core_storage_values.c|Raylib's suggest]] is like this. 

It is intended to make binary file. 

<WRAP center round tip 90%>
Note : I modified integer to float
</WRAP>
 

<file raylib saveandload.cpp>
// Save integer value to storage file (to defined position)
// NOTE: Storage positions is directly related to file memory layout (4 bytes each integer)
bool SaveStorageValue(unsigned int position, float value, const char* _fileName)
{
    bool success = false;
    unsigned int dataSize = 0;
    unsigned int newDataSize = 0;
    unsigned char *fileData = LoadFileData(_fileName, &dataSize);
    unsigned char *newFileData = NULL;

    if (fileData != NULL)
    {
        if (dataSize <= (position*sizeof(float)))
        {
            // Increase data size up to position and store value
            newDataSize = (position + 1)*sizeof(float);
            newFileData = (unsigned char *)RL_REALLOC(fileData, newDataSize);

            if (newFileData != NULL)
            {
                // RL_REALLOC succeded
                float *dataPtr = (float *)newFileData;
                dataPtr[position] = value;
            }
            else
            {
                // RL_REALLOC failed
                TraceLog(LOG_WARNING, "FILEIO: [%s] Failed to realloc data (%u), position in bytes (%u) bigger than actual file size", *_fileName, dataSize, position*sizeof(int));

                // We store the old size of the file
                newFileData = fileData;
                newDataSize = dataSize;
            }
        }
        else
        {
            // Store the old size of the file
            newFileData = fileData;
            newDataSize = dataSize;

            // Replace value on selected position
            float *dataPtr = (float *)newFileData;
            dataPtr[position] = value;
        }

        success = SaveFileData(_fileName, newFileData, newDataSize);
        RL_FREE(newFileData);

        TraceLog(LOG_INFO, "FILEIO: [%s] Saved storage value: %i", _fileName, value);
    }
    else
    {
        TraceLog(LOG_INFO, "FILEIO: [%s] File created successfully", _fileName);

        dataSize = (position + 1)*sizeof(float);
        fileData = (unsigned char *)RL_MALLOC(dataSize);
        float *dataPtr = (float *)fileData;
        dataPtr[position] = value;

        success = SaveFileData(_fileName, fileData, dataSize);
        UnloadFileData(fileData);

        TraceLog(LOG_INFO, "FILEIO: [%s] Saved storage value: %i", _fileName, value);
    }

    return success;
}

// Load float value from storage file (from defined position)
// NOTE: If requested position could not be found, value 0 is returned
float LoadStorageValue(unsigned int position, const char* _fileName)
{
    float value = 0;
    unsigned int dataSize = 0;
    unsigned char *fileData = LoadFileData(_fileName, &dataSize);

    if (fileData != NULL)
    {
        if (dataSize < (position*sizeof(float))) TraceLog(LOG_WARNING, "FILEIO: [%s] Failed to find storage position: %i", _fileName, position);
        else
        {
            float *dataPtr = (float *)fileData;
            value = dataPtr[position];
        }

        UnloadFileData(fileData);

       TraceLog(LOG_INFO, "FILEIO: [%s] Loaded storage value: %f", _fileName, value);
    }

    return value;
}
</file>

But by this way, saved file is binary. I don't like this binary file.  


===== JSON File Example ===== 

==== 1. External Library ==== 

I think [[https://github.com/nlohmann/json|nlohmann Json Library]] is good json parser library for c++. 

Just download single json.hpp file from [[https://github.com/nlohmann/json/tree/develop/single_include/nlohmann|singleinclude ]]


==== 2. required header file ==== 

this is required header file 

<code raylib>
#include "utils/json.hpp"
#include <iostream>
#include <fstream>
</code> 

and this is my real c++ header file

<file raylib config.h> 
#pragma once
#ifndef __CONFIG__
#define __CONFIG__
#include "utils/json.hpp"
#include <iostream>
#include <fstream>
// 로고, 메인메뉴, 게임 화면 등 각각의 씬
enum class Scene 
{
    logo = 0, titleMenu, game, scoreScene, settingScreen
};

// 전역적으로 사용할 싱글톤 클래스
class SceneManager 
{
    private:
        SceneManager() {} 
        static SceneManager* instance; 

    public:

        static SceneManager* GetInstance()
        {
            if (instance != nullptr)
            {
                return instance;
            }else
            {
                instance = new SceneManager();
                return instance;
            }
        }

        bool SaveJson();
        bool LoadJson();
        bool gameExit;
        Scene scene;
        Scene lastSce;
        float volume = 1.0f;
        bool isLog = false;
};

 #endif

</file> 

==== 3. using json library ==== 

By this way, You can save and load json file 

<file raylib config.cpp>
#include "config.h"

// Save Setting to json file
bool SceneManager::SaveJson()
{
    using namespace nlohmann;

    json j;
    j["Name"] = "DK Flappy Bird!";
    j["SoundVolume"] = volume;
    j["bLog"] = isLog;


    // write prettified JSON to another file
    std::ofstream o("settings.json");
    if (o.bad())
    {
        return false;
    }
    
    o << std::setw(4) << j << std::endl;
    o.close();

    return true;
}

bool SceneManager::LoadJson()
{
    using namespace nlohmann;

    std::ifstream f("settings.json");

    if (f.bad())
    {
        return false;
    }

    json data = json::parse(f);
    volume = data["SoundVolume"];
    isLog = data["bLog"];
    f.close();
    return true;

}
</file> 


===== Related Tutorial ===== 

[[raylib:json_파일_저장_및_읽기|Raylib Json File save and load]]