使用了OpenGL的图形包，实现用橡皮筋技术绘制折线或者矩形。绘制的形状可有右键选择-Using the OpenGL graphics package, to achieve technical draw a line with a rubber band or a rectangle. May have to draw the shape of the right choice

绘制直线包括橡皮筋技术，代码完整，可以直接运行矩形绘制-the cpp can print line and rectangle

OpenGL实现折线和矩形的橡皮筋绘制，鼠标右键菜单控制功能选择-OpenGL implementation polyline and draw a rubber band rectangle, right-click menu control options