From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@freedesktop.org Subject: [Bug 93594] Flickering Shadows in The Talos Principle Date: Wed, 17 Feb 2016 16:51:46 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0203949149==" Return-path: Received: from culpepper.freedesktop.org (unknown [131.252.210.165]) by gabe.freedesktop.org (Postfix) with ESMTP id D295D6EA3C for ; Wed, 17 Feb 2016 16:51:47 +0000 (UTC) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============0203949149== Content-Type: multipart/alternative; boundary="14557279070.B4A9.2380"; charset="UTF-8" --14557279070.B4A9.2380 Date: Wed, 17 Feb 2016 16:51:47 +0000 MIME-Version: 1.0 Content-Type: text/plain https://bugs.freedesktop.org/show_bug.cgi?id=93594 --- Comment #10 from Marek Olšák --- (In reply to Michel Dänzer from comment #9) > Note that AFAIK using things like derivatives in non-uniform control flow > isn't supported by GLSL. What's the original GLSL shader? True. The GLSL shader is using discard followed by fwidth. This is undefined behavior. Therefore, it's an application bug. The easy workaround would be to disable register allocation in st/mesa to get a quasi-SSA form and trivially move KILL_IF to the end of the shader if the app is detected to be Talos Principle. -- You are receiving this mail because: You are the assignee for the bug. --14557279070.B4A9.2380 Date: Wed, 17 Feb 2016 16:51:47 +0000 MIME-Version: 1.0 Content-Type: text/html

Comment # 10 on bug 93594 from 
(In reply to Michel Dänzer from comment #9)
> Note that AFAIK using things like derivatives in non-uniform control flow
> isn't supported by GLSL. What's the original GLSL shader?

True.

The GLSL shader is using discard followed by fwidth. This is undefined
behavior.

Therefore, it's an application bug.

The easy workaround would be to disable register allocation in st/mesa to get a
quasi-SSA form and trivially move KILL_IF to the end of the shader if the app
is detected to be Talos Principle.

You are receiving this mail because:
  • You are the assignee for the bug.
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