justhomework/OpenGL/hello/src/main.cpp

#include "source.h"

int mode = 0;
int model = 0;

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);

int main() {

  // 设置 glfw
  glfwInit();
  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
  glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);

  // 创建窗口
  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);

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

  // 设置视口
  glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
  glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
  glfwSetCursorPosCallback(window, mouse_callback);
  glfwSetScrollCallback(window, scroll_callback);

  // 反转y轴
  // stbi_set_flip_vertically_on_load(true);

  // 加载着色器
  Shader ourShader("src/model.vs", "src/model.fs");
  // 加载模型
  Model Model1("resources/models/nanosuit/nanosuit.obj");
  // Model ourModel("resources/models/bugatti/bugatti.obj");
  // Model ourModel("resources/models/eyeball/eyeball.obj");
  Model Model2("resources/models/clock/Clock_obj.obj");

  Model *ourModel = &Model1;

  // 开启深度测试
  glEnable(GL_DEPTH_TEST);

  // 循环渲染
  while (!glfwWindowShouldClose(window)) {

    if (model == 0)
      ourModel = &Model1;
    else
      ourModel = &Model2;

    // 计算帧时间差
    float currentFrame = glfwGetTime();
    deltaTime = currentFrame - lastFrame;
    lastFrame = currentFrame;

    // 处理输入
    processInput(window);

    // 设置为白色
    glClearColor(0.8f, 0.8f, 0.8f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    if (mode)
      // 线框模式
      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    else
      // 面模式
      glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

    // 绘制
    ourShader.use();
    // view/projection transformations
    glm::mat4 projection =
        glm::perspective(glm::radians(camera.Zoom),
                         (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
    glm::mat4 view = camera.GetViewMatrix();
    ourShader.setMat4("projection", projection);
    ourShader.setMat4("view", view);

    // render the loaded model
    glm::mat4 model = glm::mat4(1.0f);
    model = glm::translate(model, glm::vec3(0.0f, 0.0f, 0.0f));
    model = glm::scale(model, glm::vec3(1.0f, 1.0f, 1.0f));
    model = glm::rotate(model, glm::radians(float(10*glfwGetTime())), glm::vec3(0.0f, 1.0f, 0.0f));
    ourShader.setMat4("model", model);
    ourModel->Draw(ourShader);

    // 检查并调用事件，交换缓冲
    glfwSwapBuffers(window);
    glfwPollEvents();
  }

  // 释放资源
  glfwTerminate();
  return 0;
}

// 处理输入
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);
  if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_PRESS)
    camera.ProcessKeyboard(UP, deltaTime);
  if (glfwGetKey(window, GLFW_KEY_M) == GLFW_PRESS)
    mode = !mode;
  if (glfwGetKey(window, GLFW_KEY_F1) == GLFW_PRESS)
    model = 0;
  if (glfwGetKey(window, GLFW_KEY_F2) == GLFW_PRESS)
    model = 1;
}

// 窗口大小改变时回调该函数
void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
  glViewport(0, 0, width, height);
}

void mouse_callback(GLFWwindow *window, double xpos, double ypos) {
  camera.ProcessMouseMovement(xpos, ypos);
}

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