OpenGL/src/main.cpp

#include "camera.hpp"
#include "glad/glad.h"
#include <GLFW/glfw3.h>
#include <cassert>
#include <glm/glm.hpp>
#include <mesh.hpp>
#include <shader.hpp>
#include <texture.hpp>

#define UNUSED(x) (void)(x)

glm::vec3 processInput(GLFWwindow *window);
void framebuffer_size_callback(GLFWwindow *window, int width, int height);
void mouse_callback(GLFWwindow *window, double xpos, double ypos);

float deltaTime = 0;

GLFWwindow *init() {
  glfwInit();
  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

  GLFWwindow *window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
  assert(window && "Window Failed");
  glfwMakeContextCurrent(window);

  int is_ok = 0;
  is_ok = gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
  assert(is_ok && "Failed to init glad");
  glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);

  glViewport(0, 0, 800, 600);
  glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
  glfwSetCursorPosCallback(window, mouse_callback);
  return window;
}

void showFPS(GLFWwindow *window, double delta) {
  char title[22];
  title[21] = '\0';
  snprintf(title, 20, "OpenGl FPS: [%3.2f]", (1 / delta));
  glfwSetWindowTitle(window, title);
}

int main(void) {
  glm::vec3 lightPos = glm::vec3(1, 2.0f, 1);
  glm::vec3 lightColor = glm::vec3(1);

  GLFWwindow *window = init();
  Camera *cam = new Camera(glm::vec3(0), 0, 0, 45, 800.0 / 600);
  glfwSetWindowUserPointer(window, cam);

  Shader *cubeShader = new Shader("./shaders/lighting/Vert.glsl",
                                  "./shaders/lighting/Frag.glsl");
  Shader *lightShader = new Shader("./shaders/lighting/Vert.glsl",
                                   "./shaders/lighting/LightFrag.glsl");

  Mesh *cube = new Mesh(cubeShader, "./cube.obj");
  Mesh *light = new Mesh(lightShader, "./cube.obj");
  cube->setOwnedShader(true);
  light->setOwnedShader(true);

  light->setPosition(lightPos);
  light->setScale(glm::vec3(.3));

  glEnable(GL_DEPTH_TEST);
  float lastFrame = 0;
  while (!glfwWindowShouldClose(window)) {
    float currentFrame = (float)glfwGetTime();
    deltaTime = currentFrame - lastFrame;
    lastFrame = currentFrame;
    showFPS(window, deltaTime);

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

    Shader *s = cube->getShader();
    s->use();
    s->setVec3("lightColor", lightColor);
    s->setVec3("ourColor", glm::vec3(0.24725, 0.1995, 0.0745));
    s->setVec3("lightPos", lightPos);
    s->setVec3("viewPos", cam->getPos());

    s->setVec3("light.ambient", glm::vec3(0.2));
    s->setVec3("light.diffuse", glm::vec3(0.5));
    s->setVec3("light.specular", glm::vec3(1));
    s->setVec3("light.position", lightPos);

    s->setVec3("material.ambient", glm::vec3(1.0, 0.5, 0.31));
    s->setVec3("material.diffuse", glm::vec3(1.0, 0.5, 0.31));
    s->setVec3("material.specular", glm::vec3(0.5));
    s->setFloat("material.shininess", 32);
    cube->draw(cam);

    s = light->getShader();
    s->use();
    s->setVec3("ourColor", lightColor);
    light->draw(cam);

    glfwSwapBuffers(window);
    glfwPollEvents();
    glm::vec3 mov = processInput(window);
    mov *= deltaTime;
    cam->addFPos(mov);
  }

  delete cam;
  delete cube;
  delete light;
  glfwTerminate();
  return 0;
}

glm::vec3 processInput(GLFWwindow *window) {
  glm::vec3 mov = glm::vec3(0);
  if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
    glfwSetWindowShouldClose(window, true);

  if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
    mov += glm::vec3(1, 0, 0);
  if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
    mov -= glm::vec3(1, 0, 0);
  if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
    mov += glm::vec3(0, 0, 1);
  if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
    mov -= glm::vec3(0, 0, 1);
  if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS)
    mov += glm::vec3(0, 1, 0);
  if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS)
    mov -= glm::vec3(0, 1, 0);

  mov *= 5;
  return mov;
}

void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
  UNUSED(window);
  glViewport(0, 0, width, height);
  Camera *cam = (Camera *)glfwGetWindowUserPointer(window);
  if (cam)
    cam->aspect = (float)width / height;
}

void mouse_callback(GLFWwindow *window, double xpos, double ypos) {
  static float xprev = 0.0, yprev = 0.0;

  float xchange = xpos - xprev;
  float ychange = yprev - ypos;
  xprev = xpos;
  yprev = ypos;

  float sensitivity = 0.1f;
  xchange *= sensitivity;
  ychange *= sensitivity;

  Camera *cam = (Camera *)glfwGetWindowUserPointer(window);
  if (cam)
    cam->addRotate(xchange, ychange);
}