OPENCV下的贝塞尔曲线绘制，可用鼠标控制曲线形状，键盘控制曲线显示,Bezier curves under OPENCV drawn curve can be used to control the shape of the mouse, keyboard control curve shows

读取dxf文件，并利用opencv画出2D形状(Read the DXF file, and draw a 2D shape using OpenCV)