OpenGL : papan catur NIM

adapun contoh code salah satu simbol diatas ialah :

void tampilsimbol(int i)
{
    if(i%2==0){
        glColor3f(1.0f,0.0f,1.0f); //warna pink
    }else {glColor3f(0.0f,0.0f,1.0f);} // warna hitam
    glBegin(GL_QUADS);//buat persegi warna putih/hitam
        glVertex2d(0,0);
        glVertex2d(0,10);
        glVertex2d(10,10);
        glVertex2d(10,0);
    glEnd();
    glColor3f(1.0f, 0.0f, 0.0f); //warna merah
    glBegin(GL_LINE_STRIP); //buat garis segiempat
        glVertex2d(0,0);
        glVertex2d(0,10);
        glVertex2d(10,10);
        glVertex2d(10,0);
    glEnd();
    if(i%2==1){
        glColor3f(1.0f,0.0f,1.0f); //warna pink
    }else {glColor3f(0.0f,0.0f,1.0f);} // warna hitam
    glBegin(GL_POLYGON); //buat objek
        glVertex2d(4,4);
        glVertex2d(5,1);
        glVertex2d(6,4);
        glVertex2d(9,5);
        glVertex2d(6,6);
        glVertex2d(5,9);
        glVertex2d(4,6);
        glVertex2d(1,5);
        glVertex2d(4,5);
    glEnd();
    glFlush();
}