video: allow configuring the output brightness

jay-config/src/_private/client.rs

@@ -795,6 +795,13 @@ impl Client {
         });
     }
 
+    pub fn connector_set_brightness(&self, connector: Connector, brightness: Option<f64>) {
+        self.send(&ClientMessage::ConnectorSetBrightness {
+            connector,
+            brightness,
+        });
+    }
+
     pub fn connector_get_scale(&self, connector: Connector) -> f64 {
         let res = self.send_with_response(&ClientMessage::ConnectorGetScale { connector });
         get_response!(res, 1.0, ConnectorGetScale { scale });

jay-config/src/_private/ipc.rs

@@ -538,6 +538,10 @@ pub enum ClientMessage<'a> {
         color_space: ColorSpace,
         transfer_function: TransferFunction,
     },
+    ConnectorSetBrightness {
+        connector: Connector,
+        brightness: Option<f64>,
+    },
 }
 
 #[derive(Serialize, Deserialize, Debug)]

jay-config/src/video.rs

@@ -285,6 +285,22 @@ impl Connector {
     pub fn set_colors(self, color_space: ColorSpace, transfer_function: TransferFunction) {
         get!().connector_set_colors(self, color_space, transfer_function);
     }
+
+    /// Sets the brightness of the output.
+    ///
+    /// By default or when `brightness` is `None`, the brightness depends on the
+    /// transfer function:
+    ///
+    /// - [`TransferFunction::DEFAULT`]: The maximum brightness of the output.
+    /// - [`TransferFunction::PQ`]: 203 cd/m^2.
+    ///
+    /// This should only be used with the PQ transfer function. If the default transfer
+    /// function is used, you should instead calibrate the hardware directly.
+    ///
+    /// This has no effect unless the vulkan renderer is used.
+    pub fn set_brightness(self, brightness: Option<f64>) {
+        get!().connector_set_brightness(self, brightness);
+    }
 }
 
 /// Returns all available DRM devices.