From 69b9a14b960526d08e145b37fcad6b236ec8ec45 Mon Sep 17 00:00:00 2001
From: Alex <alexisr245@gmail.com>
Date: Sat, 4 Jul 2026 08:57:15 +0200
Subject: [PATCH] fix(wireplumber): show correct volume on Bluetooth sinks

The mixer-api is configured with the linear scale (0), so volume_ holds
the raw linear gain. The perceptual "cubic" value shown by wpctl and
exposed as {volume} is cbrt(linear), but update() computed pow(volume_, 3)
instead. Cubing under-reads every volume below max and collapses small
linear gains to 0% -- which is why the default Bluetooth sink (whose
normal levels map to low linear gains, e.g. wpctl 0.55 -> linear 0.166)
displayed 0% while wpctl reported a normal, unmuted volume.

Replace the inverted conversions with the correct cube-root/cube pair in
the display path, the scroll-scale conversions (cubic / cubic_percent),
and the max-volume ceiling mapping so scrolling and the cap stay
consistent with the corrected {volume}.

Fixes #5159.
---
 src/modules/wireplumber.cpp | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/modules/wireplumber.cpp b/src/modules/wireplumber.cpp
index 876c199d..74563c5d 100644
--- a/src/modules/wireplumber.cpp
+++ b/src/modules/wireplumber.cpp
@@ -547,8 +547,11 @@ auto waybar::modules::Wireplumber::update() -> void {
     label_.get_style_context()->remove_class("source-muted");
   }
 
-  double vol_cube = pow(volume_, 3);
-  double source_vol_cube = pow(source_volume_, 3);
+  // mixer-api is configured with the linear scale, so volume_ holds the raw linear gain. The
+  // perceptual "cubic" value shown by wpctl and used for {volume} is cbrt(linear), not linear^3.
+  // Cubing here drives small linear gains (typical for Bluetooth sinks) to 0%.
+  double vol_cube = cbrt(volume_);
+  double source_vol_cube = cbrt(source_volume_);
 
   int vol = round(vol_cube * 100.0);
   int source_vol = round(source_vol_cube * 100.0);
@@ -622,10 +625,10 @@ bool waybar::modules::Wireplumber::handleScroll(GdkEventScroll* e) {
     step = config_["scroll-step"].asDouble();
   }
   if (config_["max-volume"].isDouble()) {
-    // {volume} is displayed as cubic-percent (pow(volume_, 3) * 100), while volume_/newVol are
+    // {volume} is displayed as cubic-percent (cbrt(volume_) * 100), while volume_/newVol are
     // linear gains. Map the documented cubic-percent ceiling into the linear domain the clamp
-    // operates in, restoring the 0.15.0 cap semantics (e.g. 130 -> cbrt(1.3) linear -> 130%).
-    maxVolume = cbrt(config_["max-volume"].asDouble() / 100.0);
+    // operates in, restoring the 0.15.0 cap semantics (e.g. 130 -> pow(1.3, 3) linear -> 130%).
+    maxVolume = pow(config_["max-volume"].asDouble() / 100.0, 3);
   }
 
   double vol = volume_;
@@ -635,11 +638,11 @@ bool waybar::modules::Wireplumber::handleScroll(GdkEventScroll* e) {
   }
 
   if (scale == "cubic") {
-    vol = pow(vol, 3);
+    vol = cbrt(vol);
   } else if (scale == "db") {
     vol = log10(vol) * 20.0;
   } else if (scale == "cubic_percent") {
-    vol = pow(vol, 3) * 100.0;
+    vol = cbrt(vol) * 100.0;
   }
 
   double newVol = vol;
@@ -650,11 +653,11 @@ bool waybar::modules::Wireplumber::handleScroll(GdkEventScroll* e) {
   }
 
   if (scale == "cubic") {
-    newVol = cbrt(newVol);
+    newVol = pow(newVol, 3);
   } else if (scale == "db") {
     newVol = exp10(newVol / 20.0);
   } else if (scale == "cubic_percent") {
-    newVol = cbrt(newVol / 100.0);
+    newVol = pow(newVol / 100.0, 3);
   }
 
   if (dir == SCROLL_DIR::UP) {