void drawDiamond(){
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glColor3f(0, 1, 0);
glBegin(GL_TRIANGLE_FAN);
glVertex3f(0, 10, 0);
glVertex3f(7, 0, 7);
glVertex3f(7, 0, -7);
glVertex3f(-7, 0, -7);
glVertex3f(-7, 0, 7);
glVertex3f(7, 0, 7);
glEnd();
glBegin(GL_TRIANGLE_STRIP);
glVertex3f(-7, -5, 7);
glVertex3f(-7, 0, 7);
glVertex3f(-7, -5, -7);
glVertex3f(-7, 0, -7);
glVertex3f(7, -5, -7);
glVertex3f(7, 0, -7);
glVertex3f(7, -5, 7);
glVertex3f(7, 0, 7);
glVertex3f(-7, -5, 7);
glVertex3f(-7, 0, 7);
glEnd();
glBegin(GL_TRIANGLES);
glVertex3f(7, -5, -7);
glVertex3f(7, -5, 7);
glVertex3f(-7, -5, 7);
glEnd();
}