Preliminary computer graphics - 2

Many online tutorials to learn to configure the environment, to use the software in here has.

First graphics program:

// ConsoleApplication1.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include "pch.h"
#include <iostream>
#include <GLFW/glfw3.h>  

// Window dimensions    
const GLuint WIDTH = 1600, HEIGHT = 900;

void display()
{
    // do some change begauce glfw's axis is different
    GLfloat vertices[3][3] = { { 0.0, 10.0, 0.0 }, { -5.0, 0.0, 0.0 }, { 5.0, 0.0, 0.0 } };

    // copy from the assignment which Professor Li gave me

    // an arbitrary triangle in the plane z = 0;
    GLfloat p[3] = { 7.5, 5.0, 0.0 };
    // or set any desired initial point which is inside the triangle;
    int  j, k;
    int  rand();
    int total_points = 500;
    glBegin(GL_POINTS);
    for (k = 0; k < total_points; k++)
    {
        /* pick a random vertex from 0, 1, 2*/
        j = rand() % 3;
        // compute new location;
        p[0] = (p[0] + vertices[j][0]) / 2;
        p[1] = (p[1] + vertices[j][1]) / 2;
        // display new point
        glVertex3fv(p);
    }
    glEnd();
    glFlush();
}


int main()
{
    // learn from https://www.cnblogs.com/AnKen/p/8057000.html
    glfwInit();

    // Create a GLFWwindow object that we can use for GLFW's functions    
    GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "LearnOpenGL", nullptr, nullptr);
    if (window == nullptr)
    {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);


    // learn from https://stackoverflow.com/questions/57336940/how-to-glutdisplayfunc-glutmainloop-in-glfw 
    while (!glfwWindowShouldClose(window))
    {
        // do the drawing
        display();

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

}

// 运行程序: Ctrl + F5 或调试 >“开始执行(不调试)”菜单
// 调试程序: F5 或调试 >“开始调试”菜单

// 入门提示: 
//   1. 使用解决方案资源管理器窗口添加/管理文件
//   2. 使用团队资源管理器窗口连接到源代码管理
//   3. 使用输出窗口查看生成输出和其他消息
//   4. 使用错误列表窗口查看错误
//   5. 转到“项目”>“添加新项”以创建新的代码文件，或转到“项目”>“添加现有项”以将现有代码文件添加到项目
//   6. 将来，若要再次打开此项目，请转到“文件”>“打开”>“项目”并选择 .sln 文件