public void drawSweepGradient() {
        Shader sweepGradient = new SweepGradient(centerX, centerY, mStartColor, mEndColor);
        reDraw(sweepGradient);
    }
author : engineer
e-mail : yingkongshi11@gmail.com
time   : 2017/12/10
desc   :
version: 1.0
app/src/main/java/home/smart/fly/animations/master/widget/MasterPaintView.java