OpenGL 点画模式填充四边形

#include <windows.h>
#include <GL/glut.h>

GLint sideLen=300;

GLubyte star[]=
{
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // 32 31
    0x00,0x00,0x00,0x00,0x03,0x00,0x00,0x60, // 30 29
    0x03,0xC0,0x01,0xE0,0x01,0x30,0x06,0x40, // 28 27
    0x01,0x8F,0x78,0xC0,0x00,0x81,0xC0,0x80, // 26 25
    0x00,0xC0,0x81,0x80,0x00,0x40,0x01,0x00, // 24 23
    0x00,0x40,0x01,0x00,0x00,0x60,0x03,0x00, // 22 21
    0x00,0x60,0x03,0x00,0x00,0xE0,0x03,0x80, // 20 19
    0x00,0xC0,0x01,0x80,0x01,0x80,0x00,0xC0, // 18 17
    0x06,0x00,0x00,0x30,0x08,0x00,0x00,0x08, // 16 15
    0x10,0x00,0x00,0x04,0x3F,0xF8,0x0F,0xFE, // 14 13
    0x00,0x0C,0x18,0x00,0x00,0x04,0x10,0x00, // 12 11
    0x00,0x06,0x30,0x00,0x00,0x02,0x20,0x00, // 10 9
    0x00,0x01,0x40,0x00,0x00,0x01,0x40,0x00, // 8 7
    0x00,0x00,0x80,0x00,0x00,0x00,0x80,0x00, // 6 5
    0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00, // 4 3
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00  // 2 1
};

void display()
{
    glClearColor(1,1,1,1);
    glColor3f(1,0,0);
    glClear(GL_COLOR_BUFFER_BIT);
    glViewport(0,0,sideLen,sideLen);
    glRectf(-0.8,-0.8,0.8,0.8);
    glViewport(sideLen,0,sideLen,sideLen);
    glEnable(GL_POLYGON_STIPPLE);
    glPolygonStipple(star);
    glColor3f(1,0,0);
    glRectf(-0.8,-0.8,0.8,0.8);
    glDisable(GL_POLYGON_STIPPLE);
    glFlush();
}

int main()
{
    glutInitWindowSize(sideLen*2,sideLen);
    glutCreateWindow("2 Squares");
    glutDisplayFunc(display);
    glutMainLoop();
    return 0;
}