使用opengl 绘制9个点，理解各个参数的含义

 // SimpleTest1.cpp : 定义控制台应用程序的入口点。
 //

 #include "stdafx.h"
 #include<gl/glut.h>
 #include<iostream>
 using namespace std;
 void DrawTriggle()
 {
     glPointSize();
     glColor4f(1.0,0.0,0.0,0.6);
     glColor4f(0.5,0.8,,0.6);
     glBegin(GL_POINTS);
         glVertex3f(0.0,0.0,0.0);
         glVertex3f(0.9,0.0,0.0);
         glVertex3f(0.9,0.9,0.0);
         glVertex3f(0.0,0.9,0.0);
     glEnd();
     glColor4f(0.3,,,0.6);
     glBegin(GL_POINTS);
         glVertex3f(-0.9,0.9,0.0);
     glEnd();
 glColor4f(,,0.1,0.6);
     glBegin(GL_POINTS);
         glVertex3f(-0.9,0.0,0.0);
         glVertex3f(-0.9,-0.9,0.0);
     glEnd();
     glColor4f(,,0.5,0.1);
     glBegin(GL_POINTS);
         glVertex3f(0.9,-0.9,0.0);
         glVertex3f(0.0,-0.9,0.0);
     glEnd();
     glFlush();
 }

 void init()
 {
     glClearColor(1.0,1.0,1.0,0.0);
     glutInitWindowPosition(,);
     glutInitWindowSize(,);
     glutCreateWindow("simpletest window");
     gluLookAt(0.0,0.0,-1.0,0.0,0.0,-0.0,-,0.0,0.0);
     glutDisplayFunc(&DrawTriggle);
 }
 int _tmain(int argc, _TCHAR* argv[])
 {
     glutInit(&argc,(char**)argv);
     glutInitDisplayMode(GLUT_RGBA  );
     init();
     std::cout<<"out: enter main loop"<<std::endl;;
     glutMainLoop();
     return ;
 }