FastBlur.java 文件源码

public static void blur(Bitmap bkg, View view) {
    long startMs = System.currentTimeMillis();
    float radius = 15;
    float scaleFactor = 8;
    //放大到整个view的大小
    bkg = DrawableProvider.getReSizeBitmap(bkg, view.getMeasuredWidth(), view.getMeasuredHeight());

    Bitmap overlay = Bitmap.createBitmap((int) (view.getMeasuredWidth() / scaleFactor)
            , (int) (view.getMeasuredHeight() / scaleFactor), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(overlay);
    canvas.translate(-view.getLeft() / scaleFactor, -view.getTop() / scaleFactor);
    canvas.scale(1 / scaleFactor, 1 / scaleFactor);
    Paint paint = new Paint();
    paint.setFlags(Paint.FILTER_BITMAP_FLAG);
    canvas.drawBitmap(bkg, 0, 0, paint);
    overlay = FastBlur.doBlur(overlay, (int) radius, true);
    view.setBackgroundDrawable(new BitmapDrawable(UiUtils.getResources(), overlay));
    Log.w("test", "cost " + (System.currentTimeMillis() - startMs) + "ms");
}