From 3c84de52156c8e91cafcf64b82bf5f1dda6ce0a6 Mon Sep 17 00:00:00 2001
From: Ivan Molodetskikh <yalterz@gmail.com>
Date: Tue, 26 Mar 2024 19:53:58 +0400
Subject: wiki: Document debug options

---
 wiki/Configuration:-Debug-Options.md | 127 +++++++++++++++++++++++++++++++++++
 wiki/_Sidebar.md                     |   1 +
 2 files changed, 128 insertions(+)
 create mode 100644 wiki/Configuration:-Debug-Options.md

(limited to 'wiki')

diff --git a/wiki/Configuration:-Debug-Options.md b/wiki/Configuration:-Debug-Options.md
new file mode 100644
index 00000000..7d41d995
--- /dev/null
+++ b/wiki/Configuration:-Debug-Options.md
@@ -0,0 +1,127 @@
+### Overview
+
+Niri has several options that are only useful for debugging, or are experimental and have known issues.
+They are not meant for normal use.
+
+> [!CAUTION]
+> These options are **not** covered by the [config breaking change policy](./Configuration:-Overview.md#breaking-change-policy).
+> They can change or stop working at any point with little notice.
+
+Here are all the options at a glance:
+
+```
+debug {
+    preview-render "screencast"
+    // preview-render "screen-capture"
+    enable-overlay-planes
+    disable-cursor-plane
+    render-drm-device "/dev/dri/renderD129"
+    dbus-interfaces-in-non-session-instances
+    wait-for-frame-completion-before-queueing
+    emulate-zero-presentation-time
+    enable-color-transformations-capability
+}
+```
+
+### `preview-render`
+
+Make niri render the monitors the same way as for a screencast or a screen capture.
+
+Useful for previewing the [`block-out-from`](./Configuration:-Window-Rules.md#block-out-from) window rule.
+
+```
+debug {
+    preview-render "screencast"
+    // preview-render "screen-capture"
+}
+```
+
+### `enable-overlay-planes`
+
+Enable direct scanout into overlay planes.
+May cause frame drops during some animations on some hardware (which is why it is not the default).
+
+Direct scanout into the primary plane is always enabled.
+
+```
+debug {
+    enable-overlay-planes
+}
+```
+
+### `disable-cursor-plane`
+
+Disable the use of the cursor plane.
+The cursor will be rendered together with the rest of the frame.
+
+Useful to work around driver bugs on specific hardware.
+
+```
+debug {
+    disable-cursor-plane
+}
+```
+
+### `render-drm-device`
+
+Override the DRM device that niri will use for all rendering.
+
+You can set this to make niri use a different primary GPU than the default one.
+
+```
+debug {
+    render-drm-device "/dev/dri/renderD129"
+}
+```
+
+### `dbus-interfaces-in-non-session-instances`
+
+Make niri create its D-Bus interfaces even if it's not running as a `--session`.
+
+Useful for testing screencasting changes without having to relogin.
+
+The main niri instance will *not* currently take back the interfaces when you close the test instance, so you will need to relogin in the end to make screencasting work again.
+
+```
+debug {
+    dbus-interfaces-in-non-session-instances
+}
+```
+
+### `wait-for-frame-completion-before-queueing`
+
+Wait until every frame is done rendering before handing it over to DRM.
+
+Useful for diagnosing certain synchronization and performance problems.
+
+```
+debug {
+    wait-for-frame-completion-before-queueing
+}
+```
+
+### `emulate-zero-presentation-time`
+
+Emulate zero (unknown) presentation time returned from DRM.
+
+This is a thing on NVIDIA proprietary drivers, so this flag can be used to test that niri doesn't break too hard on those systems.
+
+```
+debug {
+    emulate-zero-presentation-time
+}
+```
+
+### `enable-color-transformations-capability`
+
+Enable the color-transformations capability of the Smithay renderer.
+May cause a slight decrease in rendering performance.
+
+Currently, should cause no visible changes in behavior, but it will be needed for HDR support whenever that happens.
+So, this flag exists to be able to make sure that nothing breaks.
+
+```
+debug {
+    enable-color-transformations-capability
+}
+```
diff --git a/wiki/_Sidebar.md b/wiki/_Sidebar.md
index eb451bfd..106313f8 100644
--- a/wiki/_Sidebar.md
+++ b/wiki/_Sidebar.md
@@ -10,6 +10,7 @@
 * [Input](./Configuration:-Input.md)
 * [Window Rules](./Configuration:-Window-Rules.md)
 * [Animations](./Configuration:-Animations.md)
+* [Debug Options](./Configuration:-Debug-Options.md)
 
 ## Development
 * [Design Principles](./Design-Principles.md)
-- 
cgit