main.cpp

#define STB_IMAGE_IMPLEMENTATION
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include "stb_image.h"
#include "Shader.h"
#include <glm.hpp>
#include <gtc/matrix_transform.hpp>
#include <gtc/type_ptr.hpp>

#include <iostream>
#include "camera.h"

void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);

// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;


// camera
Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
float deltaTime = 0.0f;	// Time between current frame and last frame
float lastFrame = 0.0f; // Time of last frame
float lastX = 400, lastY = 300;
auto firstMouse = true;


int main()
{
    // glfw: initialize and configure
    // ------------------------------
    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); // uncomment this statement to fix compilation on OS X
#endif

    // glfw window creation
    // --------------------
    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
    if (window == NULL)
    {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
    glfwSetCursorPosCallback(window, mouse_callback);
    glfwSetScrollCallback(window, scroll_callback);

    // glad: load all OpenGL function pointers
    // ---------------------------------------
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }
    glEnable(GL_DEPTH_TEST);

    // build and compile our shader zprogram
    // ------------------------------------
    Shader objectShader("object_vs.txt", "object_fs.txt");
    Shader lampShader("lamp_vs.txt", "lamp_fs.txt");

    // set up vertex data (and buffer(s)) and configure vertex attributes
    // ------------------------------------------------------------------
    float vertices[] = {
        //position            //texture    //normal
         -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,  0.0f,  0.0f, -1.0f,
          0.5f, -0.5f, -0.5f,  1.0f, 0.0f,  0.0f,  0.0f, -1.0f,
          0.5f,  0.5f, -0.5f,  1.0f, 1.0f,  0.0f,  0.0f, -1.0f,
          0.5f,  0.5f, -0.5f,  1.0f, 1.0f,  0.0f,  0.0f, -1.0f,
         -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,  0.0f,  0.0f, -1.0f,
         -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,  0.0f,  0.0f, -1.0f,

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

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

         -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,  0.0f,  -1.0f, 0.0f,
          0.5f, -0.5f, -0.5f,  1.0f, 1.0f,  0.0f,  -1.0f, 0.0f,
          0.5f, -0.5f,  0.5f,  1.0f, 0.0f,  0.0f,  -1.0f, 0.0f,
          0.5f, -0.5f,  0.5f,  1.0f, 0.0f,  0.0f,  -1.0f, 0.0f,
         -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,  0.0f,  -1.0f, 0.0f,
         -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,  0.0f,  -1.0f, 0.0f,
  
         -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,  0.0f,  1.0f, 0.0f,
          0.5f,  0.5f, -0.5f,  1.0f, 1.0f,  0.0f,  1.0f, 0.0f,
          0.5f,  0.5f,  0.5f,  1.0f, 0.0f,  0.0f,  1.0f, 0.0f,
          0.5f,  0.5f,  0.5f,  1.0f, 0.0f,  0.0f,  1.0f, 0.0f,
         -0.5f,  0.5f,  0.5f,  0.0f, 0.0f,  0.0f,  1.0f, 0.0f,
         -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,  0.0f,  1.0f, 0.0f
    };
   
    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)
    };
    auto lampPosotion = glm::vec3(-1.3f, 3.0f, -1.5f);

    unsigned int VBO, cubeVAO;
    glGenVertexArrays(1, &cubeVAO);
    glGenBuffers(1, &VBO);


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

    glBindVertexArray(cubeVAO);
    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    // texture coord attribute
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);
    // normal coord attribute
    glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(5 * sizeof(float)));
    glEnableVertexAttribArray(2);

    unsigned int lightVAO;
    glGenVertexArrays(1, &lightVAO);
    glBindVertexArray(lightVAO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);


    // load and create a texture 
    // -------------------------
    unsigned int texture1, texture2;
    // texture 1
    // ---------
    glGenTextures(1, &texture1);
    glBindTexture(GL_TEXTURE_2D, texture1);
    // set the texture wrapping parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);	// set texture wrapping to GL_REPEAT (default wrapping method)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    // set texture filtering parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    // load image, create texture and generate mipmaps
    int width, height, nrChannels;
    stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture's on the y-axis.
    // The FileSystem::getPath(...) is part of the GitHub repository so we can find files on any IDE/platform; replace it with your own image path.
    unsigned char* data = stbi_load("wall.jpg", &width, &height, &nrChannels, 0);
    if (data)
    {
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
        glGenerateMipmap(GL_TEXTURE_2D);
    }
    else
    {
        std::cout << "Failed to load texture" << std::endl;
    }
    stbi_image_free(data);
    // texture 2
    // ---------
    glGenTextures(1, &texture2);
    glBindTexture(GL_TEXTURE_2D, texture2);
    // set the texture wrapping parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);	// set texture wrapping to GL_REPEAT (default wrapping method)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    // set texture filtering parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    // load image, create texture and generate mipmaps
    data = stbi_load("awesomeface.png", &width, &height, &nrChannels, 0);
    if (data)
    {
        // note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
        glGenerateMipmap(GL_TEXTURE_2D);
    }
    else
    {
        std::cout << "Failed to load texture" << std::endl;
    }
    stbi_image_free(data);

 
    auto lightColor = glm::vec3(1.0f, 1.0f, 1.0f);
    


    // render loop
    // -----------
    while (!glfwWindowShouldClose(window))
    {
        // input
        processInput(window);

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

        // bind textures on corresponding texture units
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, texture1);
        glActiveTexture(GL_TEXTURE1);
        glBindTexture(GL_TEXTURE_2D, texture2);

        // calculate delta time
        float currentFrame = glfwGetTime();
        deltaTime = currentFrame - lastFrame;
        lastFrame = currentFrame;

        // activate shader
        objectShader.use();
        objectShader.setInt("texture1", 0);
        objectShader.setInt("texture2", 1);
        objectShader.setVec3("lightColor", lightColor);
        objectShader.setVec3("lightPos", lampPosotion);
        objectShader.setVec3("viewPos", camera.Position);

        // pass projection matrix to shader (note that in this case it could change every frame)
        auto projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
        objectShader.setMat4("projection", projection);

        // camera/view transformation
        auto view = camera.GetViewMatrix();
        objectShader.setMat4("view", view);   

        // render boxes
        glBindVertexArray(cubeVAO);
        for (unsigned int i = 0; i < 10; i++)
        {
            glm::mat4 model = glm::mat4(1.0f);
            model = glm::translate(model, cubePositions[i]);
            float angle = 20.0f * i;
            model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f));
            objectShader.setMat4("model", model);

            glDrawArrays(GL_TRIANGLES, 0, 36);
        }

        //render lamp
        lampShader.use();
        lampShader.setMat4("projection", projection);
        lampShader.setMat4("view", view);
        glm::mat4 model = glm::mat4(1.0f);
        model = glm::translate(model, lampPosotion);
        model = glm::scale(model, glm::vec3(0.3f, 0.3f, 0.3f));
        lampShader.setMat4("model", model);
        lampShader.setVec3("lightColor", lightColor);

        glBindVertexArray(lightVAO);
        glDrawArrays(GL_TRIANGLES, 0, 36);

        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
        // -------------------------------------------------------------------------------
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    // optional: de-allocate all resources once they've outlived their purpose:
    // ------------------------------------------------------------------------
    glDeleteVertexArrays(1, &cubeVAO);
    glDeleteVertexArrays(1, &lightVAO);
    glDeleteBuffers(1, &VBO);

    // glfw: terminate, clearing all previously allocated GLFW resources.
    // ------------------------------------------------------------------
    glfwTerminate();
    return 0;
}

// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow* window)
{
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);

    if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
        camera.ProcessKeyboard(FORWARD, deltaTime);
    if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
        camera.ProcessKeyboard(BACKWARD, deltaTime);
    if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
        camera.ProcessKeyboard(LEFT, deltaTime);
    if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
        camera.ProcessKeyboard(RIGHT, deltaTime);
}

// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
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 mouse_callback(GLFWwindow* window, double xpos, double ypos) {

    if (firstMouse)
    {
        lastX = xpos;
        lastY = ypos;
        firstMouse = false;
    }

    float xoffset = xpos - lastX;
    float yoffset = lastY - ypos; // reversed since y-coordinates range from bottom to top
    lastX = xpos;
    lastY = ypos;

    const float sensitivity = 0.05f;
    xoffset *= sensitivity;
    yoffset *= sensitivity;

    camera.ProcessMouseMovement(xoffset, yoffset);

}

void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
    camera.ProcessMouseScroll(yoffset);
}