Graffiti Canvas Library (涂鸦画板工具库)
“graffitiCanvas” is a canvas drawing tool based on javascript native canvas, which can draw many shapes.
Browser compatibility supports IE8+ (support IE5+ with excanvas).
“graffitiCanvas”是一个基于javascript原生canvas的画板绘制工具，支持绘制多种形状的图形。
浏览器兼容性支持IE8+（借助excanvas可以支持IE5+）。
1. 支持线条、三角形、矩形、平行四边形、梯形、多边形、圆形、箭头等图形的绘制
