Add an adaptive_sync output command

This enables/disables adaptive synchronization on the output.

For now, the default is disabled because it might cause flickering on
some hardware if clients don't submit frames at regular enough
intervals. In the future an "auto" option will only enable adaptive sync
if a fullscreen client opts-in via a Wayland protocol.

1 files changed, 9 insertions, 0 deletions

diff --git a/sway/sway-output.5.scd b/sway/sway-output.5.scd
index 0f9fe208..b71e5744 100644
--- a/sway/sway-output.5.scd
+++ b/sway/sway-output.5.scd
@@ -148,6 +148,15 @@ must be separated by one space. For example:
         optimal max_render_time value may vary based on the parent compositor
         rendering timings.
 
+*output* <name> adaptive_sync on|off
+        Enables or disables adaptive synchronization (often referred to as Variable
+        Refresh Rate, or by the vendor-specific names FreeSync/G-Sync).
+
+        Adaptive sync allows clients to submit frames a little to late without
+        having to wait a whole refresh period to display it on screen. Enabling
+        adaptive sync can improve latency, but can cause flickering on some
+        hardware.
+
 # SEE ALSO
 
 *sway*(5) *sway-input*(5)