四边形网格扫描转化与交互式编辑

实现四边形网格交互式编辑：要求实现四边形扫描转化算法，以此为基础，实现四边形网格中所有四边形的扫描转化、颜色添充；并通过交互改变四边形顶点位置体会交互式图形系统特点。-Quadrilateral mesh scan conversion and interactive editing

Quadrilateral grid interactive editing: Quadrilateral scan conversion algorithms required to achieve, on this basis, to achieve all quadrilateral quadrilateral scan conversion, color Tim charge　and changing the quadrilateral vertex position by exchanging experience the interactive features of the graphics system.