OpenGL+Xcode环境配置

步骤1：安装brew

打开终端，复制下面一行命令执行，安装需要一分钟左右，过程中需要输入密码，其他无需操作

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

步骤2：安装GLFW、GLEW库

在终端输入：

$ brew install glew

$ brew install glfw

【注：有的教程中是brew install glfw3，博主这样进行安装后代码不能正常运行，找不到库文件，改为glfw其实就是默认安装glfw的最新版本】

步骤3：下载glad库

打开GLAD的在线服务，将语言(Language)设置为C/C++，在API选项中，选择3.3以上的OpenGL(gl)版本。之后将模式(Profile)设置为Core，并且保证生成加载器(Generate a loader)的选项是选中的。都选择完之后，点击生成(Generate)按钮来生成库文件，下载zip文件

【以上三步不能正常完成的，可在以下地址下载博主整理好的库文件：

https://github.com/xiaobooo/OpenGL/tree/master/Base】

步骤4：在项目中进行配置

单击项目，进入项目设置页面

Build Phases --->Link Binary With Libraries

添加OpenGL.framework, libglfw.lib, libGLEW.dylib【后两个文件可以在下载的glfw/glew库文件中的lib文件夹中找到】

项目头文件有引入glut.h的还需要添加GLUT.framework

Build Settings --->Search Paths

在Header Search Paths中添加/usr/local/include【通过brew安装glfw/glew的直接这样添加即可，稳稳地】

需要GLAD库的还需要添加glad库文件中的include文件夹的位置

在Library Search Paths中添加/usr/local/lib

需要glad的同学还需要将glad.c放入工程中，直接拖入即可：

大功告成，测试代码：

//
//  main.cpp
//  Triangle
//
//  Created by boone on 2018/7/3.
//  Copyright © 2018年 boone. All rights reserved.
//
#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <iostream>

using namespace std;

const unsigned int WIDTH = 800;

const unsigned int HEIGHT = 800;

//顶点着色器
const char *vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
"   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\0";
//片段着色器
const char *fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
"   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
"}\n\0";

void framebuffer_size_callback(GLFWwindow* window, int width, int height){
    glViewport(0, 0, width, height);
}
void pressInput(GLFWwindow* window){
    if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
}

int main(){
    //初始化窗口
    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);     //兼容Mac OS X
    
    GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "Xiaobooo's Triange", NULL, NULL);
    
    //判断窗口创建是否成功
    if(window == NULL){
        cout<<"Fail to Create Window"<<endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
    
    // glad: load all OpenGL function pointers
    // ---------------------------------------
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }
    
    //创建顶点着色器
    int vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
    glCompileShader(vertexShader);
    //检查顶点着色器编译是否成功
    int success;
    char infoLog[512];
    glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
    if(!success){
        glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
        cout<<"ERROR: VertexShader Compile Fail"<<infoLog<<endl;
    }
    
    //创建片段着色器
    int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
    glCompileShader(fragmentShader);
    
    //检查片段着色器是否编译成功
    glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
    if(!success){
        glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
        cout<<"ERROR: FragmentShader Compile Fail"<<infoLog<<endl;
    }
    
    //链接着色器
    int shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram, vertexShader);
    glAttachShader(shaderProgram, fragmentShader);
    glLinkProgram(shaderProgram);
    
    //检查着色器链接是否成功
    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
    if(!success){
        glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
        cout<<"ERROR: Shader Link Fail"<<infoLog<<endl;
    }
    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);
    
    //设置顶点坐标
    float vertices[]={
        -0.5f, -0.5f, 0.0f, // left
        0.5f, -0.5f, 0.0f, // right
        0.0f,  0.5f, 0.0f  // top
    };
    
    unsigned int VBO, VAO;
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);
    // bind the Vertex Array Object first, then bind and set vertex buffer(s), and then configure vertex attributes(s).
    glBindVertexArray(VAO);
    
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
    
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    
    // note that this is allowed, the call to glVertexAttribPointer registered VBO as the vertex attribute's bound vertex buffer object so afterwards we can safely unbind
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    
    // You can unbind the VAO afterwards so other VAO calls won't accidentally modify this VAO, but this rarely happens. Modifying other
    // VAOs requires a call to glBindVertexArray anyways so we generally don't unbind VAOs (nor VBOs) when it's not directly necessary.
    glBindVertexArray(0);

    
    //循环渲染
    while(!glfwWindowShouldClose(window)){
        
        pressInput(window);
        
        glClearColor(0.8f, 0.8f, 0.8f, 0.8f);
        glClear(GL_COLOR_BUFFER_BIT);
        
        glUseProgram(shaderProgram);
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES,0,3);
        
        glfwSwapBuffers(window);
        glfwPollEvents();
    }
    
    glDeleteVertexArrays(1,&VAO);
    glDeleteBuffers(1,&VBO);
    
    //释放分配的资源
    glfwTerminate();
    return 0;
}

博主opengl学习日记：https://github.com/xiaobooo/OpenGL