video: allow configuring the output brightness

src/ifs/jay_compositor.rs

@@ -73,7 +73,7 @@ impl Global for JayCompositorGlobal {
     }
 
     fn version(&self) -> u32 {
-        15
+        16
     }
 
     fn required_caps(&self) -> ClientCaps {

src/ifs/jay_randr.rs

@@ -32,6 +32,7 @@ const TEARING_SINCE: Version = Version(3);
 const FORMAT_SINCE: Version = Version(8);
 const FLIP_MARGIN_SINCE: Version = Version(10);
 const COLORIMETRY_SINCE: Version = Version(15);
+const BRIGHTNESS_SINCE: Version = Version(16);
 
 impl JayRandr {
     pub fn new(id: JayRandrId, client: &Rc<Client>, version: Version) -> Self {
@@ -187,6 +188,22 @@ impl JayRandr {
                 color_space: node.global.bcs.get().name(),
             });
         }
+        if self.version >= BRIGHTNESS_SINCE {
+            if let Some(lum) = node.global.luminance {
+                self.client.event(BrightnessRange {
+                    self_id: self.id,
+                    min: lum.min,
+                    max: lum.max,
+                    max_fall: lum.max_fall,
+                });
+            }
+            if let Some(lux) = node.global.persistent.brightness.get() {
+                self.client.event(Brightness {
+                    self_id: self.id,
+                    lux,
+                });
+            }
+        }
     }
 
     fn send_error(&self, msg: &str) {
@@ -464,6 +481,26 @@ impl JayRandrRequestHandler for JayRandr {
         c.connector.set_colors(cs, tf);
         Ok(())
     }
+
+    fn set_brightness(&self, req: SetBrightness<'_>, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        let Some(c) = self.get_output_node(req.output) else {
+            return Ok(());
+        };
+        c.global.set_brightness(Some(req.lux));
+        Ok(())
+    }
+
+    fn unset_brightness(
+        &self,
+        req: UnsetBrightness<'_>,
+        _slf: &Rc<Self>,
+    ) -> Result<(), Self::Error> {
+        let Some(c) = self.get_output_node(req.output) else {
+            return Ok(());
+        };
+        c.global.set_brightness(None);
+        Ok(())
+    }
 }
 
 object_base! {

src/ifs/wl_output.rs

@@ -122,6 +122,7 @@ pub struct PersistentOutputState {
     pub vrr_mode: Cell<&'static VrrMode>,
     pub vrr_cursor_hz: Cell<Option<f64>>,
     pub tearing_mode: Cell<&'static TearingMode>,
+    pub brightness: Cell<Option<f64>>,
 }
 
 #[derive(Eq, PartialEq, Hash, Debug)]
@@ -332,9 +333,21 @@ impl WlOutputGlobal {
     pub fn update_color_description(&self) -> bool {
         let mut luminance = Luminance::SRGB;
         let tf = match self.btf.get() {
-            BackendTransferFunction::Default => TransferFunction::Srgb,
+            BackendTransferFunction::Default => {
+                if let Some(brightness) = self.persistent.brightness.get() {
+                    let output_max = match self.luminance {
+                        None => 80.0,
+                        Some(v) => v.max,
+                    };
+                    luminance.white.0 = luminance.max.0 * brightness / output_max;
+                }
+                TransferFunction::Srgb
+            }
             BackendTransferFunction::Pq => {
                 luminance = Luminance::ST2084_PQ;
+                if let Some(brightness) = self.persistent.brightness.get() {
+                    luminance.white.0 = brightness;
+                }
                 TransferFunction::St2084Pq
             }
         };
@@ -368,6 +381,12 @@ impl WlOutputGlobal {
         self.linear_color_description.set(cd_linear.clone());
         self.color_description.set(cd.clone()).id != cd.id
     }
+
+    pub fn set_brightness(&self, brightness: Option<f64>) {
+        self.persistent.brightness.set(brightness);
+        self.update_color_description();
+        self.state.damage(self.pos.get());
+    }
 }
 
 global_base!(WlOutputGlobal, WlOutput, WlOutputError);