cube backup.cpp

#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include "shader_loader.h"
// Window dimensions
const GLuint WIDTH = 800, HEIGHT = 600;

void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window);
std::string loadShaderSource(const char* filepath);
GLuint createShaderProgram(const char* vertexPath, const char* fragmentPath);

int main()
{
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // For MacOS
#endif

    GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "Triangle-Based Cube", NULL, NULL);
    if (window == NULL)
    {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }

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

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

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

        -0.5f, -0.5f,  0.5f,  0.0f, 1.0f, 1.0f,
         0.5f,  0.5f,  0.5f,  0.5f, 0.5f, 0.5f,
        -0.5f,  0.5f,  0.5f,  0.2f, 0.2f, 0.8f,
        
        // Left, Right, Top, Bottom faces can be added similarly
    };

    GLuint VBO, VAO;
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);

    glBindVertexArray(VAO);

    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    GLuint shaderProgram = createShaderProgram("shaders/basic.vert", "shaders/basic.frag");

    while (!glfwWindowShouldClose(window))
    {
        processInput(window);

        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glUseProgram(shaderProgram);

        glm::mat4 model = glm::mat4(1.0f);
        glm::mat4 view = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, -3.0f));
        glm::mat4 projection = glm::perspective(glm::radians(45.0f), (float)WIDTH / HEIGHT, 0.1f, 100.0f);
        glm::mat4 mvp = projection * view * model;
        glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "MVP"), 1, GL_FALSE, glm::value_ptr(mvp));

        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 12); // only front & back for demo

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);

    glfwTerminate();
    return 0;
}

void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    glViewport(0, 0, width, height);
}

void processInput(GLFWwindow *window)
{
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
}

std::string loadShaderSource(const char* filepath)
{
    std::ifstream file(filepath);
    std::stringstream buffer;
    buffer << file.rdbuf();
    return buffer.str();
}

GLuint createShaderProgram(const char* vertexPath, const char* fragmentPath)
{
    std::string vertCode = loadShaderSource(vertexPath);
    std::string fragCode = loadShaderSource(fragmentPath);

    const char* vShaderCode = vertCode.c_str();
    const char* fShaderCode = fragCode.c_str();

    GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vShaderCode, NULL);
    glCompileShader(vertexShader);

    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fShaderCode, NULL);
    glCompileShader(fragmentShader);

    GLuint shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram, vertexShader);
    glAttachShader(shaderProgram, fragmentShader);
    glLinkProgram(shaderProgram);

    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);

    return shaderProgram;
}