blur: Limit blur to the two frontmost layers

Rendering 3 or more layers of blur on top of each other makes little to
no visual difference in the final result, but it comes at a big
performance penalty. Only blurring the two frontmost layers saves a lot
of GPU time with minimal difference in output quality.

Change-Id: I9ec8129751a183db00ad200080207434f086a63e
Signed-off-by: Joey Huab <joey@evolution-x.org>
Signed-off-by: Ayan Mukherjee <mukherjeeayan725@gmail.com>
1 file changed