绘制简单的图形，包括：线条，直线，矩形，正方形，圆，椭圆，弧线；改变画笔或画刷的颜色，并且实现自定义颜色；文件保存；实现橡皮擦功能；实现画刷功能；实现喷漆功能；实现文字输入；实现照片的柔化效果和浮雕画效果-Drawing simple graphics, including: line, line, rectangular, square, circle, elliptic, curve Change the color of the paint brush or brush, and rea