点画填充多边形

#include <windows.h>
//#include <GLUT/glut.h>
#include <GL/glut.h>
#include <math.h>
#include <iostream>
using namespace std;

#define GL_PI 3.1415f

GLubyte fire[]={
    0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0x00,
    0x00,0x00,0x00,0xc0,
    0x00,0x00,0x01,0xf0,
    0x00,0x00,0x07,0xf0,
    0x0f,0x00,0x1f,0xe0,
    0x1f,0x80,0x1f,0xc0,
    0x0f,0xc0,0x3f,0x80,
    0x07,0xe0,0x7e,0x00,
    0x03,0xf0,0xff,0x80,
    0x03,0xf5,0xff,0xe0,
    0x07,0xfd,0xff,0xf8,
    0x1f,0xfc,0xff,0xe8,
    0xff,0xe3,0xbf,0x70,
    0xde,0x80,0xb7,0x00,
    0x71,0x10,0x4a,0x80,
    0x03,0x10,0x4e,0x40,
    0x02,0x88,0x8c,0x20,
    0x05,0x05,0x04,0x40,
    0x02,0x82,0x14,0x40,
    0x02,0x40,0x10,0x80,
    0x02,0x64,0x1a,0x80,
    0x00,0x92,0x29,0x00,
    0x00,0xb0,0x48,0x00,
    0x00,0xc8,0x90,0x00,
    0x00,0x85,0x10,0x00,
    0x00,0x03,0x00,0x00,
    0x00,0x00,0x10,0x00,
};


void RenderScene()
{
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glBegin(GL_POLYGON);
        glVertex2f(-20.0f,50.0f);
        glVertex2f(20.0f,50.0f);
        glVertex2f(50.0f,20.0f);
        glVertex2f(50.0f,-20.0f);
        glVertex2f(20.0f,-50.0f);
        glVertex2f(-20.0f,-50.0f);
        glVertex2f(-50.0f,-20.0f);
        glVertex2f(-50.0f,20.0f);
    glEnd();
    glutSwapBuffers();

}

void ChangeSize(GLsizei w,GLsizei h)
{
    if(h==0)
        h = 1;

    GLfloat aspectRatio = (GLfloat)w/(GLfloat)h;

    glViewport(0,0,w,h);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    if(w<=h)
        glOrtho(-100,100,-100/aspectRatio,100/aspectRatio,100.0,-100.0);
    else
        glOrtho(-100*aspectRatio,100*aspectRatio,-100,100,100.0,-100.0);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

}

void SetupRC()
{
    glClearColor(0.0f,0.0f,0.0f,1.0f);
    glColor3f(1.0f,0.0f,0.0f);
    glEnable(GL_POLYGON_STIPPLE);
    glPolygonStipple(fire);
}


int main(int argc, char *argv[])
{
   glutInit(&argc,argv);
   glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
   glutInitWindowSize(800,600);
   glutCreateWindow("Simple");

   glutDisplayFunc(RenderScene);
   glutReshapeFunc(ChangeSize);

   SetupRC();
   glutMainLoop();
   return 0;
}