一、構建GLFW

GLFW 是配合 OpenGL 使用的輕量級工具程序庫，縮寫自 Graphics Library Framework（圖形庫框架）。GLFW 的主要功能是創建並管理窗口和 OpenGL 上下文，同時還提供了處理手柄、鍵盤、鼠標輸入的功能。

下載地址：https://www.glfw.org/download.html

我們可以選擇直接下載編譯好的庫，也可以下載源文件然后通過camke來自己編譯，區別是如果用cmake庫的話，在執行成功以后，會直接將生成的庫與頭文件分別添加到系統路徑，也就是/usr/local/include和/usr/local/lib。

這里我選擇了下載編譯好的庫

二、配置GLAD

GLAD是一個開源項目： https://github.com/Dav1dde/glad
同時它還提供了一個在線服務： https://glad.dav1d.de/
打開GLAD在線服務，如圖11所示，我設置語言為C/C++，gl版本選擇4.6：

點擊GENERATE按鈕，GLAD現在應該提供給你了一個zip壓縮文件，包含兩個頭文件目錄，和一個glad.c文件

三、創建XCode項目

3.1 新建XCode項目，如圖13所示，選擇”Command Line Tool“:

3.2 導入第三方庫：

將之前下載的編譯好的GLFW庫和GLAD文件導入項目中

3.3 鏈接第三方庫：

設置libs搜索路徑：

設置頭文件的搜索路徑：

3.4 把glad.c加入到工程項目中：

3.5 示例代碼：

 1 #include <glad.h>
 2 #include <glfw3.h>
 3 
 4 #include <iostream>
 5 
 6 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
 7 void processInput(GLFWwindow *window);
 8 
 9 // settings
10 const unsigned int SCR_WIDTH = 800;
11 const unsigned int SCR_HEIGHT = 600;
12 
13 int main()
14 {
15     // glfw: initialize and configure
16     // ------------------------------
17     glfwInit();
18     glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
19     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
20     glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
21 
22 #ifdef __APPLE__
23     glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
24 #endif
25 
26     // glfw window creation
27     // --------------------
28     GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
29     if (window == NULL)
30     {
31         std::cout << "Failed to create GLFW window" << std::endl;
32         glfwTerminate();
33         return -1;
34     }
35     glfwMakeContextCurrent(window);
36     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
37 
38     // glad: load all OpenGL function pointers
39     // ---------------------------------------
40     if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
41     {
42         std::cout << "Failed to initialize GLAD" << std::endl;
43         return -1;
44     }
45 
46     // render loop
47     // -----------
48     while (!glfwWindowShouldClose(window))
49     {
50         // input
51         // -----
52         processInput(window);
53 
54         // render
55         // ------
56         glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
57         glClear(GL_COLOR_BUFFER_BIT);
58 
59         // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
60         // -------------------------------------------------------------------------------
61         glfwSwapBuffers(window);
62         glfwPollEvents();
63     }
64 
65     // glfw: terminate, clearing all previously allocated GLFW resources.
66     // ------------------------------------------------------------------
67     glfwTerminate();
68     return 0;
69 }
70 
71 // process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
72 // ---------------------------------------------------------------------------------------------------------
73 void processInput(GLFWwindow *window)
74 {
75     if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
76         glfwSetWindowShouldClose(window, true);
77 }
78 
79 // glfw: whenever the window size changed (by OS or user resize) this callback function executes
80 // ---------------------------------------------------------------------------------------------
81 void framebuffer_size_callback(GLFWwindow* window, int width, int height)
82 {
83     // make sure the viewport matches the new window dimensions; note that width and
84     // height will be significantly larger than specified on retina displays.
85     glViewport(0, 0, width, height);
86 }