绘制半长轴和半短轴分别为a,b的椭圆
//绘制半长轴和半短轴分别为a,b的椭圆void ellipse(double a,double b){ int n = 1000; double t = 0.0; glBegin( GL_LINE_LOOP); for (int i = 0; i < n; ++i) { t = i * 2 * 3.14159 / n; glVertex2f(a*cos(t), b*sin(t)); } glEnd();}