From 33bcc43fdf6cb2594d02c9bafafa8f1e2609730a Mon Sep 17 00:00:00 2001
From: Roman Gilg <subdiff@gmail.com>
Date: Wed, 11 Dec 2019 04:24:05 +0100
Subject: [PATCH] [scenes/opengl] Remove glDrawBuffer call

Summary:
According to Gl 3.2 (page 501) and 4.5 (page 204) specs the initial state of
the default framebuffer is already BACK. Therefore we do not need to set it
explicitly.

When we draw in the future to alternative framebuffers which do not have back
buffers this call is fatal.

Test Plan: No tearing on Wayland, tearing as before on X11.

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D25868
---
 plugins/scenes/opengl/scene_opengl.cpp | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/plugins/scenes/opengl/scene_opengl.cpp b/plugins/scenes/opengl/scene_opengl.cpp
index 1953ab4b38..5c61a4ae2e 100644
--- a/plugins/scenes/opengl/scene_opengl.cpp
+++ b/plugins/scenes/opengl/scene_opengl.cpp
@@ -337,9 +337,6 @@ SceneOpenGL::SceneOpenGL(OpenGLBackend *backend, QObject *parent)
         init_ok = false;
         return;
     }
-    if (!glPlatform->isGLES() && !m_backend->isSurfaceLessContext()) {
-        glDrawBuffer(GL_BACK);
-    }
 
     m_debug = qstrcmp(qgetenv("KWIN_GL_DEBUG"), "1") == 0;
     initDebugOutput();