#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 "shader.h"
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#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);
 
// 窗口大小
const unsigned int SCR_WIDTH = 1280;
const unsigned int SCR_HEIGHT = 720;
 
float factor = 0.2f;
double fov = 45.0;
 
float vertices[] = {
    -0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
    0.5f, -0.5f, -0.5f, 1.0f, 0.0f,
    0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
    0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
    -0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
    -0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
 
    -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
    0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
    0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
    0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
    -0.5f, 0.5f, 0.5f, 0.0f, 1.0f,
    -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
 
    -0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
    -0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
    -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
    -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
    -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
    -0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
 
    0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
    0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
    0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
    0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
    0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
    0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
 
    -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
    0.5f, -0.5f, -0.5f, 1.0f, 1.0f,
    0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
    0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
    -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
    -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
 
    -0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
    0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
    0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
    0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
    -0.5f, 0.5f, 0.5f, 0.0f, 0.0f,
    -0.5f, 0.5f, -0.5f, 0.0f, 1.0f
};
 
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)
};
 
glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 4.0f);
glm::vec3 cameraFront = glm::vec3(0.0f, 0.0f, -1.0f);
glm::vec3 cameraUp = glm::vec3(0.0f, 1.0f, 0.0f);
 
float deltaTime = 0.0f;  //两帧之间的间隔时间
float lastFrame = 0.0f;  //上一帧绘制的时间
 
float lastX = 400, lastY = 300;
bool firstMouse = true;
float yaw = 0.0f, pitch = 0.0f;
 
//观察者摄像机
Camera camera(glm::vec3(0.0f, 0.0f, 4.0f));
 
int main() {
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
    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);
 
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }
 
    //获取最大属性数量
    int nrAttributes;
    glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, &nrAttributes);
    std::cout << "max support nums:" << nrAttributes << std::endl;
 
    glEnable(GL_DEPTH_TEST);
 
    //创建我们的着色器
    Shader shader("Shader.vs", "Shader.fs");
 
 
 
    //第一个环境
    unsigned int VBO, VAO;
    glGenVertexArrays(1, &VAO);
    glBindVertexArray(VAO);
 
    glGenBuffers(1, &VBO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);
 
    //unsigned int EBO;
    //glGenBuffers(1, &EBO);
    //glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
    //glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
 
    //纹理1
    unsigned int texture;
    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    //设置纹理包装和过滤的方式
    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);
    int width, height, nrChannels;
    stbi_set_flip_vertically_on_load(true);
    unsigned char* data = stbi_load(/*"zhou_yu.bmp"*/"beauty.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 load image resources!" << std::endl;
    stbi_image_free(data);
 
    //纹理2
    unsigned int texture2;
    glGenTextures(1, &texture2);
    glActiveTexture(GL_TEXTURE1);   //激活纹理1对象
    glBindTexture(GL_TEXTURE_2D, texture2);
    //设置纹理环绕和过滤的方式
    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);
    //加载图片
    stbi_set_flip_vertically_on_load(true);
    unsigned char* data2 = stbi_load("awesomeface.png", &width, &height, &nrChannels, 0);
    if (data2) {
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data2);
        glGenerateMipmap(GL_TEXTURE_2D);
    }
    else
        std::cout << "failed load image resources!" << std::endl;
    stbi_image_free(data2);
 
    //告诉OpenGL哪个采样器属于哪个纹理单元
    shader.use();
    shader.setInt("texture1", 0);
    shader.setInt("texture2", 1);
 
    // 变换
    //glm::mat4 trans;
    //trans = glm::scale(trans, glm::vec3(0.5f, 0.5f, 0.5f));
    //trans = glm::rotate(trans, /*glm::radians(90.0f)*/(float)glfwGetTime(), glm::vec3(0.0f, 0.0f, 1.0f));
 
 
 
    while (!glfwWindowShouldClose(window)) {
         
        processInput(window);
 
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, texture);
        glActiveTexture(GL_TEXTURE1);
        glBindTexture(GL_TEXTURE_2D, texture2);
 
        float currentFrame = glfwGetTime();
        deltaTime = currentFrame - lastFrame;
        lastFrame = currentFrame;
 
        shader.use();
        glm::mat4 projection;
        projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
 
        //float radius = 10.0f;
        //float camX = sin(glfwGetTime()) * radius;
        //float camZ = cos(glfwGetTime()) * radius;
        glm::mat4 view;
        //view = glm::lookAt(glm::vec3(camX, 0.0, camZ), glm::vec3(0.0, 0.0, 0.0), glm::vec3(0.0, 1.0, 0.0));
        view = camera.GetViewMatrix();//glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);
        shader.setMat4("view", glm::value_ptr(view));
        shader.setMat4("projection", glm::value_ptr(projection));
 
        glBindVertexArray(VAO);
        for (int i = 0; i < 10; ++i) {
            glm::mat4 model;
            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));
            shader.setMat4("model", glm::value_ptr(model));
            glDrawArrays(GL_TRIANGLES, 0, 36);
        }
 
        glfwSwapBuffers(window);
        glfwPollEvents();
    }
 
    glBindVertexArray(0);
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glfwTerminate();
    return 0;
}
 
void processInput(GLFWwindow *window) {
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
 
    //if (glfwGetKey(window, GLFW_KEY_UP) == GLFW_PRESS) {
    //  factor += 0.01f;
    //  if (factor > 1.0f)
    //      factor = 1.0f;
    //}
 
    //if (glfwGetKey(window, GLFW_KEY_DOWN) == GLFW_PRESS) {
    //  factor -= 0.01f;
    //  if (factor < 0.0f)
    //      factor = 0.0f;
    //}
 
 
    //float cameraSpeed = 2.5f * deltaTime; //�ƶ��ٶ�
    if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
        camera.ProcessKeyboard(FORWARD, deltaTime);
        //cameraPos += cameraSpeed * cameraFront;
 
    if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
        camera.ProcessKeyboard(BACKWARD, deltaTime);
        //cameraPos -= cameraSpeed * cameraFront;
 
    if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
        camera.ProcessKeyboard(LEFT, deltaTime);
        //cameraPos -= glm::normalize(glm::cross(cameraFront, cameraUp) * cameraSpeed);
 
    if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
        camera.ProcessKeyboard(RIGHT, deltaTime);
        //cameraPos += glm::normalize(glm::cross(cameraFront, cameraUp) * cameraSpeed);
 
}
 
void mouse_callback(GLFWwindow* window, double xPos, double yPos) {
    //static int x = 0;
 
    //x++;
    //if (x == 10) {
    //  int y = 0;
    //}
    if (firstMouse) {
        lastX = xPos;
        lastY = yPos;
        firstMouse = false;
    }
 
    float xoffset = lastX - xPos;   //别忘了，在窗口中，左边的坐标小于右边的坐标，而我们需要一个正的角度
    float yoffset = lastY - yPos;   //同样，在窗口中，下面的坐标大于上面的坐标，而我们往上抬头的时候需要一个正的角度
    lastX = xPos;
    lastY = yPos;
 
    camera.ProcessMouseMovement(xoffset, yoffset);
 
    //float sensitivity = 0.05f;
    //xoffset *= sensitivity;
    //yoffset *= sensitivity;
 
    //yaw += xoffset;
    //pitch += yoffset;
 
    //if (pitch > 89.0f)
    //  pitch = 89.0f;
    //if (pitch < -89.0f)
    //  pitch = -89.0f;
 
    //glm::vec3 front;
    //front.x = -sin(glm::radians(yaw));
    //front.y = sin(glm::radians(pitch));
    //front.z = -cos(glm::radians(pitch)) * cos(glm::radians(yaw));
    //cameraFront = glm::normalize(front);
}
 
//鼠标滚轮消息回调
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset) {
    camera.ProcessMouseScroll(yoffset);
    //if (fov >= 1.0 && fov <= 45.0)
    //  fov -= yoffset;
    //if (fov <= 1.0)
    //  fov = 1.0;
    //if (fov >= 45.0)
    //  fov = 45.0;
}
 
void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
    glViewport(0, 0, width, height);
}