OpenGL绘制复杂图形

#include <windows.h>    // Windows的头文件

#include <gl\gl.h>        // OpenGL32库的头文件
#include <gl\glu.h>        // GLu32库的头文件
#include <gl\glaux.h>    // GLaux库的头文件
#include <gl\glut.h>    // Glut库头文件

#include <math.h>
#include <iostream>
#include <fstream>
using namespace std;

#pragma comment( lib, "opengl32.lib")    // OpenGL32连接库
#pragma comment( lib, "glu32.lib")        // GLu32连接库
#pragma comment( lib, "glaux.lib")        // GLaux连接库
#pragma comment( lib, "glut.lib")        // Glut链接库

int screenWidth=640;
int screenHeight=480;

void myInit()
{
    glClearColor(1.0,1.0,1.0,0.0);            //设置背景颜色为亮白
    glColor3f(0.0f,0.0f,0.0f);                //设置绘图颜色为黑色
    glPointSize(4.0);                        //设置点的大小为4*4像素
    glMatrixMode(GL_PROJECTION);            //设置合适的矩阵
    glLoadIdentity();                        
    gluOrtho2D(0.0,screenWidth,0.0,screenHeight);
}

void drawLine(GLint x1,GLint y1,GLint x2,GLint y2)
{
    glBegin(GL_LINES);
    glVertex2i(x1,y1);
    glVertex2i(x2,y2);
    glEnd();
}


void myDisplay()
{
    fstream inStream;
    inStream.open("dino.txt",ios::in);
    if(inStream.fail())
        return;
    glClear(GL_COLOR_BUFFER_BIT);
    GLint numpolys,numLines,x,y;
    inStream>>numpolys;

    for(int j=0;j<numpolys;j++)
    {
        inStream>>numLines;
        glBegin(GL_LINE_STRIP);
        for(int i=0;i<numLines;i++)
        {
            inStream>>x>>y;
            glVertex2i(x,y);
        }
        glEnd();    
    }

    glFlush();
    inStream.close();
}

void main(int argc, char **argv)
{
    glutInit(&argc,argv);                        //初始化工具包    
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);//设置显示模式
    glutInitWindowSize(640,480);                //设置窗口大小
    glutInitWindowPosition(100,150);            //设置窗口在屏幕上的位置
    glutCreateWindow("my first attempt");        //打开屏幕窗口

    //注册回调函数
    glutDisplayFunc(myDisplay);

    myInit();
    glutMainLoop();                                //进入循环
}

数据在这里：http://web.cs.wpi.edu/~gogo/courses/cs4731/assignments/ass1/dino.dat