Available Environment Variables

KWin supports a number of environment variables to overwrite some settings or checks. The following variables are supported:

KWIN_COMPOSE

The environment variable KWIN_COMPOSE enforces a compositing backend or forces compositing completely off. The following values are supported:

O: OpenGL backend (either OpenGL 1, OpenGL 2 or OpenGL ES 2.0)
O1: OpenGL 1 backend
O2: OpenGL 2 backend
X: XRender backend
N: No Compositing

KWIN_NVIDIA_HACK

By default KWin uses an NVIDIA specific hack to set __GL_YIELD to NOTHING. By setting "KWIN_NVIDIA_HACK" to "0" this behavior can be disabled.

KWIN_DIRECT_GL

KWin determines whether LIBGL_ALWAYS_INDIRECT has to be set by an external helper application and a driver whitelist of the drivers known to perform well with direct rendering. By setting the environment variable KWIN_DIRECT_GL to 1 the checks are not performed and LIBGL_ALWAYS_INDIRECT is not set.

KWIN_GL_DEBUG

By setting KWIN_GL_DEBUG to 1 the OpenGL rendering can be debugged visually. All geometries which are rendered are overlayed by a wireframe. The wireframe is not available in OpenGL ES 2.0. The environment variable is supported since 4.7.

KWIN_FORCE_LANCZOS

The lanczos filter is controlled by the scale method in the advanced compositing settings and a blacklist of drivers known to break with this filter. The setting and the blacklist can be overruled by setting KWIN_FORCE_LANCZOS to 1. This environment variable is supported since 4.8.

KWIN_OPENGL_INTERFACE

By setting KWIN_OPENGL_INTERFACE to egl the OpenGL based compositor uses the EGL platform interface instead of the GLX. This environment variable is supported since 4.10.