说明：  线性填充算法 可自己定义画笔大小、任意画笔及填充颜色。用画笔画任意包含多个闭合区域，可以分别对各个闭合区域进行不同颜色填充
(Linear filling algorithm can be their own definition of brush size, arbitrary brush and fill color. Arbitrary strokes with a painting, includes a number of closed areas, can be closed for each region filled with different colors)