BaseFragment.java 文件源码

protected Path createArcPath(View view, float endX, float endY, float radius){
    Path arcPath=new Path();
    float startX=view.getTranslationX();
    float startY=view.getTranslationY();
    float midX = startX + ((endX - startX) / 2);
    float midY = startY + ((endY - startY) / 2);
    float xDiff = midX - startX;
    float yDiff = midY - startY;

    double angle = (Math.atan2(yDiff, xDiff) * (180 / Math.PI)) - 90;
    double angleRadians = Math.toRadians(angle);

    float pointX = (float) (midX + radius * Math.cos(angleRadians));
    float pointY = (float) (midY + radius * Math.sin(angleRadians));

    arcPath.moveTo(startX, startY);
    arcPath.cubicTo(startX,startY,pointX,pointY, endX, endY);
    return arcPath;
}