椭圆拟合，用于在jpg格式的图片上寻找椭圆，并进行拟合,Ellipse fitting to the picture in jpg format to find oval, and fitting

opengl绘制参数曲线，这里绘制的是很多条短直线逼近一个椭圆，比较适合新手(OpenGL draw parameter curve, here is drawing a lot of short straight line approaching an ellipse, more suitable for novice)

用Bresenham算法和中点算法画圆和椭圆(Using the Bresenham algorithm and the midpoint algorithm of circle and ellipse)