-OPENGL3-

#ifndef WINDOW_H
#define WINDOW_H
#undef GLFW_DLL
#include <GLFW/glfw3.h>

#define GLEW_STATIC
#include <GL/glew.h>



class FrameWindow
{
public:
    FrameWindow(int width,int height,const char*title="OpenGL");
    virtual ~FrameWindow();
    GLFWwindow *getWindow();
private:
     GLFWwindow *window;
     int w;
     int h;
};

FrameWindow::FrameWindow(int width,int height,const char*title){
    w = width;
    h = height;
    glfwInit();
    window = glfwCreateWindow(width,height,title,NULL,NULL);
    glfwMakeContextCurrent(window);
    glewInit();

}
FrameWindow::~FrameWindow(){
    glfwDestroyWindow(window);
    glfwTerminate();
}
GLFWwindow * FrameWindow::getWindow(){
    return window;
}

#endif // WINDOW_H

#ifndef LOADSHADER_H
#define LOADSHADER_H


#include <GL/glew.h>

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>


using namespace std;
struct LoadShader
{
    LoadShader()=default;
    LoadShader(const char*vertPath, const char* fragPath){
        load(vertPath,fragPath);
    }

    string _readFile(const char *path){
        ifstream stream;
        stringstream ss;
        stream.exceptions(ifstream::badbit);
        try
        {
            stream.open(path);    // open file
            ss << stream.rdbuf(); // get strings from file
        } catch (ifstream::failure e)
        {
            cout << "ERROR::OPEN FILE:" << path << endl;
        }
        // close file handle
        stream.close();

        // get str() from stringstream
        string shaderCode = ss.str();
        return shaderCode;
    }

    void _loadVertexShader(const char *path){

        // read shader code
        auto handle = _readFile(path);
        const char * shaderCode = handle.c_str();
        // Vertex shader
        vertexShader = glCreateShader( GL_VERTEX_SHADER );
        glShaderSource( vertexShader, 1, &shaderCode, NULL );
        glCompileShader( vertexShader );
        GLint success;
        GLchar infoLog[512];

        glGetShaderiv( vertexShader, GL_COMPILE_STATUS, &success );
        if ( !success )
        {
            glGetShaderInfoLog( vertexShader, 512, NULL, infoLog );
            std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
        }

    }

    void _loadFragmentShader(const char *path){
        // read shader code
        auto handle = _readFile(path);
        const char * shaderCode = handle.c_str();
        // Vertex shader
        fragmentShader = glCreateShader( GL_FRAGMENT_SHADER );
        glShaderSource( fragmentShader, 1, &shaderCode, NULL );
        glCompileShader( fragmentShader );
        GLint success;
        GLchar infoLog[512];

        glGetShaderiv( fragmentShader, GL_COMPILE_STATUS, &success ); // Get Compile status
        if ( !success )
        {
            glGetShaderInfoLog( fragmentShader, 512, NULL, infoLog );
            std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
        }
    }

    void load(const char* vertShaderPath, const char* fragShaderPath){
        _loadVertexShader(vertShaderPath);
        _loadFragmentShader(fragShaderPath);


        // create shader program and check it
        GLint success;
        GLchar infoLog[512];
        shaderProgram = glCreateProgram();
        glAttachShader(shaderProgram,vertexShader);
        glAttachShader(shaderProgram,fragmentShader);
        glLinkProgram(shaderProgram );
        glGetProgramiv( shaderProgram, GL_LINK_STATUS, &success );  // Get Link Status
        if (!success)
        {
           glGetProgramInfoLog( shaderProgram, 512, NULL, infoLog );
           std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
        }
        // Delete the shaders as they‘re linked into our program now and no longer necessery
        glDeleteShader( vertexShader );
        glDeleteShader( fragmentShader );
    }

    void use(){
        glUseProgram(shaderProgram);
    }

    void setBool(const char *name, bool value) const
    {
        glUniform1i(glGetUniformLocation(shaderProgram, name), (int)value);
    }
    void setInt(const char *name, int value) const
    {
        glUniform1i(glGetUniformLocation(shaderProgram,name), value);
    }
    // ------------------------------------------------------------------------
    void setFloat(const char *name, float value) const
    {
        glUniform1f(glGetUniformLocation(shaderProgram, name), value);
    }
    // ------------------------------------------------------------------------
    void setVec2(const char *name, const glm::vec2 &value) const
    {
        glUniform2fv(glGetUniformLocation(shaderProgram,name), 1, &value[0]);
    }

    void setVec2(const char *name, float x, float y) const
    {
        glUniform2f(glGetUniformLocation(shaderProgram,name), x, y);
    }
    // ------------------------------------------------------------------------
    void setVec3(const char *name, const glm::vec3 &value) const
    {
        glUniform3fv(glGetUniformLocation(shaderProgram,name), 1, &value[0]);
    }
    void setVec3(const char *name, float x, float y, float z) const
    {
        glUniform3f(glGetUniformLocation(shaderProgram,name), x, y, z);
    }
    // ------------------------------------------------------------------------
    void setVec4(const char *name, const glm::vec4 &value) const
    {
        glUniform4fv(glGetUniformLocation(shaderProgram,name), 1, &value[0]);
    }
    void setVec4(const char *name, float x, float y, float z, float w)
    {
        glUniform4f(glGetUniformLocation(shaderProgram,name), x, y, z, w);
    }

    void setMat2(const char*name, const glm::mat2 &mat) const
    {
        glUniformMatrix2fv(glGetUniformLocation(shaderProgram, name), 1, GL_FALSE,glm::value_ptr(mat));
    }

    void setMat3(const char*name, const glm::mat3 &mat){
        GLuint location = glGetUniformLocation(shaderProgram, name);
        glUniformMatrix3fv(location,1, GL_FALSE, &mat[0][0]);
    }

    void setMat4(const char *name , const glm::mat4 &mat){
        GLuint location = glGetUniformLocation(shaderProgram, name);
        glUniformMatrix4fv(location,1, GL_FALSE, glm::value_ptr(mat));
    }

    GLuint shaderProgram;
    GLuint vertexShader;
    GLuint fragmentShader;
};





#endif // LOADSHADER_H

#ifndef GLFWCAMERA_H
#define GLFWCAMERA_H

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>


class GLFWCamera{
public:
    GLFWCamera();
    ~GLFWCamera(){}
    enum CAMERA_MOVEMENT{
        FORWARD,     // Camera move to front   ->  key:W
        BACKWARD,    // Camera move to back    ->  key:S
        LEFT,        // Camera move to left    ->  key:A
        RIGHT        // Camera move to right   ->  key:D
    };

public:
    glm::vec3 pos;
    glm::vec3 front;
    glm::vec3 up;

    // Euler Angles
   float yaw;
   float pitch;


   // Camera options
   float movementSpeed;
   float mouseSensitivity;
   float fov;

   void processFov(float yoffset){
       if(fov >= 1.0f && fov <= 45.0f){
           fov -= yoffset;
       }
       if(fov <=1.0f){
           fov = 1.0f;
       }
       if(fov >= 45.0f){
           fov = 45.0f;
       }
   }

   // build the matrix for lookAt
   glm::mat4 GetViewMatrix(){
       return glm::lookAt(pos , pos + front , up);
   }

   // process -Rotate the view-
   void processMouseMove(float xoffset, float yoffset);


   // process -W S A D-
   void processKeyboardMove(float delta, CAMERA_MOVEMENT moveDir);



   void updateFront(){
       glm::vec3 tempfront;
       tempfront.x = cos(glm::radians(yaw)) * cos(glm::radians(pitch));
       tempfront.y = sin(glm::radians(pitch));
       tempfront.z = sin(glm::radians(yaw)) * cos(glm::radians(pitch));
       this->front = glm::normalize(tempfront);
   }


};

GLFWCamera::GLFWCamera(){
    pos = glm::vec3(0.0f,0.0f,3.0f);
    up = glm::vec3(0.0f,1.0f,0.0f);
    front = glm::vec3(0.0f,0.0f,-1.0f);
    yaw = -90.0f;
    pitch = 0.0f;
    fov = 45.0f;
    movementSpeed = 2.5f;
    mouseSensitivity = 0.1f;
}

void GLFWCamera::processMouseMove(float xoffset, float yoffset)
{

    xoffset *= mouseSensitivity;
    yoffset *= mouseSensitivity;

    yaw += xoffset;
    pitch += yoffset;

    // make sure that when pitch is out of bounds, screen doesn‘t get flipped
    if (pitch > 89.0f)
        pitch = 89.0f;
    if (pitch < -89.0f)
        pitch = -89.0f;
    this->updateFront();
}

void GLFWCamera::processKeyboardMove(float delta, CAMERA_MOVEMENT moveDir)
{
    float vel = movementSpeed * delta;
    switch (moveDir)
    {
    case FORWARD:
        {
            pos += vel * front;
            break;
        }
    case BACKWARD:
        {
            pos -= vel * front;
            break;
        }
    case LEFT:
        {
            pos -= glm::normalize(glm::cross(front, up)) * vel;
            break;
        }
    case RIGHT:
        {
            pos += glm::normalize(glm::cross(front, up)) * vel;
        }
    default:
        break;
    }
}

#endif // GLFWCAMERA_H

#define GLEW_STATIC
// GLEW

#include <GL/glew.h>
#include <cstdlib>
#undef GLFW_DLL
// GLFW
#include <GLFW/glfw3.h>
#include <iostream>
#include "LoadShader.h"
#include "GLFWCamera.h"
#include "FrameWindow.h"


#define STB_IMAGE_IMPLEMENTATION
#include <stb_image.h>
#include <cmath>


#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>



const unsigned int SRC_WIDTH = 1400;
const unsigned int SRC_HEIGHT = 720;


static GLuint VAO,VBO,EBO;
static LoadShader shader;
void init();
void display();
void showFPS(GLFWwindow *);


void processInput(GLFWwindow *window);
void framebuffer_size_callback(GLFWwindow* window, int width, int height); // framezize
void mouse_callback(GLFWwindow* window, double xpos, double ypos); // Maya Alt+LeftMouse
void scroll_callback(GLFWwindow *window, double xoffset, double yoffset);


// camera
static GLFWCamera *camera;


static float lastX =  float(SRC_WIDTH) / 2.0f;
static float lastY =  float(SRC_HEIGHT) / 2.0f;

static bool firstMouse = true;

// timing
static float deltaTime = 0.0f;    // time between current frame and last frame
static float lastFrame = 0.0f;



// world space positions of our cubes
static  glm::vec3 cubePositions[] = {
        glm::vec3( 0.0f,  0.0f,  0.0f),
        glm::vec3( 2.0f,  5.0f, -15.0f),
        glm::vec3(-1.5f, -2.2f, -2.5f),
        glm::vec3(-3.8f, -2.0f, -12.3f),
        glm::vec3( 2.4f, -0.4f, -3.5f),
        glm::vec3(-1.7f,  3.0f, -7.5f),
        glm::vec3( 1.3f, -2.0f, -2.5f),
        glm::vec3( 1.5f,  2.0f, -2.5f),
        glm::vec3( 1.5f,  0.2f, -1.5f),
        glm::vec3(-1.3f,  1.0f, -1.5f)
};


void init(){
    camera = new GLFWCamera;

    float vertices[] = {
        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
         0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,

        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
         0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
        -0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,

        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
         0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
         0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
         0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
         0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
         0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
         0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,

        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f
    };

    glEnable(GL_DEPTH_TEST);

    GLuint indices[6] = {
            0, 1, 3,  // FIRST TRIANGLE
            1, 2, 3   // SECOND TRIANGLE
        };
    shader.load("shader.vert","shader.frag");
    shader.use();

    glCreateVertexArrays(1, &VAO);
    glCreateBuffers(1, &VBO);
    glCreateBuffers(1, &EBO);

    glBindVertexArray(VAO);
    glBindBuffer(GL_ARRAY_BUFFER,VBO);
    //glNamedBufferStorage(VBO,sizeof(verticels), verticels, 0);
    glBufferData(GL_ARRAY_BUFFER,sizeof(vertices), vertices, GL_STATIC_DRAW);



    glCreateBuffers(1, &EBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
    glNamedBufferStorage(EBO, sizeof(indices), indices , 0);

    // VERTEX POINTS ATTRIBUTES
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float),  (void*)0); // POS at location 0
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float))); // ST at location 1
    glEnableVertexAttribArray(1);




    cout << "GEN Texture\n";
    // loading one texture
    GLuint textureID;
    glCreateTextures(GL_TEXTURE_2D,1 , &textureID);
    glBindTexture(GL_TEXTURE_2D,textureID);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    int width, height, nrChannels;
    stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture‘s on the y-axis.
    unsigned char *data = stbi_load("wendy.png", &width, &height, &nrChannels, 0);
    if (data)
    {
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
        glGenerateMipmap(GL_TEXTURE_2D);
    }
    cout << "FREE IMAGE\n";
    stbi_image_free(data);

}

void display(){
    // per-frame time logic
            // --------------------
    float currentFrame = glfwGetTime();
    deltaTime = currentFrame - lastFrame;
    lastFrame = currentFrame;


    glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);




    glm::mat4 projection = glm::perspective(glm::radians(camera->fov),float(SRC_WIDTH) / float(SRC_HEIGHT),0.1f,  1000.0f);
    glm::mat4 view = camera->GetViewMatrix();
    // Send projection and view matrix to shader
    shader.setMat4("projection", projection);
    shader.setMat4("view", view);



    for (unsigned int i = 0; i < 10; i++)
    {
        // RULE : RST
        // FIRST WE ROTATION
        glm::mat4 tempRot = glm::mat4(1.0f);
        tempRot = glm::rotate(tempRot, float(glfwGetTime()*0.5f + float(i) ),glm::vec3(1.00f,0.0f,0.0f));
        // then translate
        glm::mat4 tempTrans = glm::mat4(1.0f);
        tempTrans = glm::translate(tempTrans,cubePositions[i]);

        // final combine one matrix
        glm::mat4 model = glm::mat4(1.0f);
        model = tempTrans * tempRot;
        // send to opengl
        shader.setMat4("model",model);
        glDrawArrays(GL_TRIANGLES,0,36);

    }


}


int main()
{
    glfwInit();
    FrameWindow FrameWindow(SRC_WIDTH,SRC_HEIGHT);
    glfwSetFramebufferSizeCallback(FrameWindow.getWindow(), framebuffer_size_callback);
    glfwSetCursorPosCallback(FrameWindow.getWindow(),mouse_callback);
    glfwSetScrollCallback(FrameWindow.getWindow(), scroll_callback);
    init();
    // RENDER--------------
    while(!glfwWindowShouldClose(FrameWindow.getWindow())){
        processInput(FrameWindow.getWindow());
        display();
        glfwSwapBuffers(FrameWindow.getWindow());
        glfwPollEvents();
    }
    delete camera;
    return 0;
}

void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    // make sure the viewport matches the new window dimensions; note that width and
    // height will be significantly larger than specified on retina displays.
    glViewport(0, 0, width, height);
}

void processInput(GLFWwindow *window)
{
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
    if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
        camera->processKeyboardMove(deltaTime,GLFWCamera::FORWARD);
    if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
        camera->processKeyboardMove(deltaTime,GLFWCamera::BACKWARD);
    if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
        camera->processKeyboardMove(deltaTime,GLFWCamera::LEFT);
    if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
        camera->processKeyboardMove(deltaTime,GLFWCamera::RIGHT);
}

// ROTATE VIEW DIR
void mouse_callback(GLFWwindow* window, double xpos, double ypos){
    int mouse_state = glfwGetMouseButton(window,GLFW_MOUSE_BUTTON_LEFT);
    int key_state = glfwGetKey(window,GLFW_KEY_LEFT_ALT);

    if( mouse_state == GLFW_PRESS && key_state== GLFW_PRESS)
    {
        if (firstMouse){
            lastX = xpos;
            lastY = ypos;
            firstMouse = false;
        }
        float xoffset = xpos - lastX;
        float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top
        lastX = xpos;
        lastY = ypos;
        camera->processMouseMove(xoffset,yoffset);
    }
    if (key_state == GLFW_RELEASE || mouse_state == GLFW_RELEASE){
        firstMouse = true;
    }

}

void scroll_callback(GLFWwindow *window, double xoffset, double yoffset){
    camera->processFov(yoffset);
}