learnOpenGL.cpp

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include "shader.h"
#include "input.h"
#include <iostream>
#include <math.h>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

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

#include <assimp/scene.h>   

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

// 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 lastX = SCR_WIDTH / 2.0f;
float lastY = SCR_HEIGHT / 2.0f;
bool firstMouse = true;


float deltaTime = 0.0f;	// Time between current frame and last frame
float lastFrame = 0.0f; // Time of last frame

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)
};

glm::vec3 pointLightPositions[] = {
        glm::vec3(0.7f,  0.2f,  2.0f),
        glm::vec3(2.3f, -3.3f, -4.0f)
};

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);

    

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

    // build and compile our shader program
    // ------------------------------------
    Shader lightingShader("vertexShader.vert", "fragmentShader.frag"); // you can name your shader files however you like
    Shader lightCubeShader("cubeVertexShader.txt","cubeFragmentShader.txt");
    // set up vertex data (and buffer(s)) and configure vertex attributes
    // ------------------------------------------------------------------
    float vertices[] = {
        // positions          // normals           // texture coords
        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
         0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
         0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -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,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
         0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
        -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,  0.0f,  1.0f,  0.0f,
        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  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,  0.0f,  0.0f,  0.0f,  1.0f,
        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  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,  1.0f,  0.0f,  0.0f,  1.0f,  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,  0.0f,  0.0f,  0.0f,  1.0f,
         0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  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, -1.0f,  0.0f,  0.0f,  1.0f,
         0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
         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,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,

        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
         0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
         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,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
    };
    
    float borderColor[] = { 1.0f, 1.0f, 0.0f, 1.0f };
    glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor);

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

    glBindVertexArray(VAO);

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

    //position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    // normal attribute
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);
    //texture attribute
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
    glEnableVertexAttribArray(2);

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

    unsigned int diffuseMap = loadTexture("container2.png");
    unsigned int specularMap = loadTexture("container2_specular.png");

    lightCubeShader.use();
    lightCubeShader.setVec3("lightColor", 1.0f, 1.0f, 1.0f);
    // render loop
    // -----------
    while (!glfwWindowShouldClose(window))
    {
        // input and register
        // -----
        processInput(window);
        glfwSetCursorPosCallback(window, mouse_callback);
        glfwSetScrollCallback(window, scroll_callback);

        // render
        // ------
        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glEnable(GL_DEPTH_TEST);

        //projection
        glm::mat4 projection = glm::mat4(1.0f);
        projection = glm::perspective(glm::radians(camera.Zoom), 800.0f / 600.0f, 0.1f, 100.0f);

        //view
        glm::mat4 view = camera.GetViewMatrix();

        
        
        //uniform matrices
        lightingShader.use();

        lightingShader.setMat4("projection", projection);
        lightingShader.setMat4("view", view);


        //uniform colors
        //directional light
        lightingShader.setVec3("dirLight.direction", 1.0f, 1.0f, 1.0f);
        lightingShader.setVec3("dirLight.ambient", 0.2f, 0.2f, 0.2f);
        lightingShader.setVec3("dirLight.diffuse", 0.5f, 0.5f, 0.5f); // darken diffuse light a bit
        lightingShader.setVec3("dirLight.specular", 1.0f, 1.0f, 1.0f);

        //pointLight[0]
        lightingShader.setVec3("pointLights[0].position", pointLightPositions[0]);
        lightingShader.setFloat("pointLights[0].constant", 1.0f);
        lightingShader.setFloat("pointLights[0].linear", 0.09);
        lightingShader.setFloat("pointLights[0].quadratic", 0.032);
        lightingShader.setVec3("pointLights[0].ambient", 0.05f, 0.05f, 0.05f);
        lightingShader.setVec3("pointLights[0].diffuse", 0.8f, 0.8f, 0.8f);
        lightingShader.setVec3("pointLights[0].specular", 1.0f, 1.0f, 1.0f);

        // pointlight[1]
        lightingShader.setVec3("pointLights[1].position", pointLightPositions[1]);
        lightingShader.setFloat("pointLights[1].constant", 1.0f);
        lightingShader.setFloat("pointLights[1].linear", 0.09);
        lightingShader.setFloat("pointLights[1].quadratic", 0.032);
        lightingShader.setVec3("pointLights[1].ambient", 0.05f, 0.05f, 0.05f);
        lightingShader.setVec3("pointLights[1].diffuse", 0.8f, 0.8f, 0.8f);
        lightingShader.setVec3("pointLights[1].specular", 1.0f, 1.0f, 1.0f);


        // spotLight
        lightingShader.setVec3("spotLight.direction", camera.Front);

        lightingShader.setFloat("spotLight.innerCutOff", glm::cos(glm::radians(12.0f)));
        lightingShader.setFloat("spotLight.outerCutOff", glm::cos(glm::radians(15.0f)));

        lightingShader.setFloat("spotLight.constant", 1.0f);
        lightingShader.setFloat("spotLight.linear", 0.09);
        lightingShader.setFloat("spotLight.quadratic", 0.032);

        lightingShader.setVec3("spotLight.diffuse", 1.0f, 1.0f, 1.0f);
        lightingShader.setVec3("spotLight.specular", 0.2f, 0.2f, 0.2f);



        //uniform material porperties
        lightingShader.setInt("material.diffuse", 0);
        lightingShader.setInt("material.specular", 1);
        lightingShader.setVec3("material.specular", 0.5f, 0.5f, 0.5f);
        lightingShader.setFloat("material.shininess", 32.0f);

        lightingShader.setVec3("viewPos", camera.Position);

        // bind diffuse map
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, diffuseMap);
        glActiveTexture(GL_TEXTURE1);
        glBindTexture(GL_TEXTURE_2D, specularMap);
        
        for(unsigned int i = 0; i < 10; i++)
        {
            //model
            glm::mat4 model = glm::mat4(1.0f);
            model = glm::translate(model, cubePositions[i]);
            lightingShader.setMat4("model", model);
            // render the cube
            glBindVertexArray(VAO);
            glDrawArrays(GL_TRIANGLES, 0, 36);  
        }
        
        lightCubeShader.use();
        lightCubeShader.setMat4("projection", projection);
        lightCubeShader.setMat4("view", view);
        for (unsigned int i = 0; i < 2; i++) {
            glm::mat4 model = glm::mat4(1.0f);
            model = glm::translate(model, pointLightPositions[i]);
            model = glm::scale(model, glm::vec3(0.2f));
            lightCubeShader.setMat4("model", model);
            // render the cube
            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, &VAO);
    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);

    float currentFrame = glfwGetTime();
    deltaTime = currentFrame - lastFrame;
    std::cout << (int)(1 / deltaTime) << "\t";
    lastFrame = currentFrame;

    float cameraSpeed = 2.5f * deltaTime; // adjust accordingly
    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);
}

// glfw: whenever the mouse moves, this callback is called
// -------------------------------------------------------
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 go from bottom to top

    lastX = xpos;
    lastY = ypos;

    camera.ProcessMouseMovement(xoffset, yoffset);
}

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

unsigned int loadTexture(char const* path)
{
    unsigned int texture;
    glGenTextures(1, &texture);

    int width, height, nrComponents;
    unsigned char* data = stbi_load(path, &width, &height, &nrComponents, 0);
    if (data)
    {
        GLenum format = GL_RGB;
        if (nrComponents == 1)
            format = GL_RED;
        else if (nrComponents == 3)
            format = GL_RGB;
        else if (nrComponents == 4)
            format = GL_RGBA;

        glBindTexture(GL_TEXTURE_2D, texture);

        glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
        glGenerateMipmap(GL_TEXTURE_2D);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        stbi_image_free(data);

    }
    else
    {
        std::cout << "Texture failed to load texture" << std::endl;
        stbi_image_free(data);

    }
    

    return texture;
}