摘要
针对编程实践中椭圆绕任意点旋转绘图的问题,介绍了单个点绕任意点旋转的问题,利用椭圆的参数方程,基于点的旋转,从而推导出椭圆绕任意点旋转后新的参数方程,进而利用新的椭圆参数方程实现旋转后椭圆的重绘。相对于利用Ellipse()函数,该方法具有所绘图形失真小、灵活性好等特点,并且适用于已知参数方程的曲线绕任意点旋转绘图的问题。
For the problem about drawing a rotated ellipse around any point in the programming practice,this paper intro- duces a problem about the rotation of a single point around any point at first,and then using the elliptic parametric equation to get a new elliptic parametric equations based on the rotation of point,at last drawing the rotated ellipse by using the new elliptic parameter equation.Comparing with using Ellipse 0 function,this method has the character of smaller graphics dis- tortion and better flexibility, also this method can be applied to drawing a rotated curve around any point which has a known parametric equation.
出处
《电脑编程技巧与维护》
2013年第14期18-19,23,共3页
Computer Programming Skills & Maintenance
关键词
设备上下文
点的旋转
椭圆旋转
Device context
The rotation of point
The rotation of ellipse
