Add --pixelformat cli argument

Enables setting --pixelformat=baseline
to force wl_buffers to use the wayland default xrgb8888

src/cli.rs

@@ -1,4 +1,4 @@
-use clap::Parser;
+use clap::{Parser, ValueEnum};
 
 #[derive(Parser)]
 #[command(author, version, long_about = None, about = "\
@@ -77,6 +77,15 @@ pub struct Cli {
     /// adjust brightness, eg. -b=-60 (default: 0)
     #[arg(short, long)]
     pub brightness: Option<i32>,
+    /// wl_buffer pixel format (default: auto)
+    #[arg(long)]
+    pub pixelformat: Option<PixelFormat>,
     /// directory with: wallpaper_dir/output/workspace_name.{jpg|png|...}
     pub wallpaper_dir: String,
 }
+
+#[derive(Copy, Clone, PartialEq, Eq, ValueEnum)]
+pub enum PixelFormat {
+    Auto,
+    Baseline,
+}

src/main.rs

@@ -35,7 +35,7 @@ use smithay_client_toolkit::reexports::protocols
     ::wp::viewporter::client::wp_viewporter::WpViewporter;
 
 use crate::{
-    cli::Cli,
+    cli::{Cli, PixelFormat},
     sway::{SwayConnectionTask, WorkspaceVisible},
     wayland::State,
 };
@@ -87,6 +87,8 @@ fn main()
         layer_shell,
         viewporter,
         wallpaper_dir,
+        force_xrgb8888: cli.pixelformat
+            .is_some_and(|p| p == PixelFormat::Baseline),
         pixel_format: None,
         background_layers: Vec::new(),
         sway_connection_task: SwayConnectionTask::new(

src/wayland.rs

@@ -49,6 +49,7 @@ pub struct State {
     pub layer_shell: LayerShell,
     pub viewporter: WpViewporter,
     pub wallpaper_dir: PathBuf,
+    pub force_xrgb8888: bool,
     pub pixel_format: Option<wl_shm::Format>,
     pub background_layers: Vec<BackgroundLayer>,
     pub sway_connection_task: SwayConnectionTask,
@@ -57,19 +58,23 @@ pub struct State {
 }
 
 impl State {
-    fn pixel_format(&mut self) -> wl_shm::Format {
+    fn pixel_format(&mut self) -> wl_shm::Format
+    {
         *self.pixel_format.get_or_insert_with(|| {
-            // Consume less gpu memory by using Bgr888 if available,
-            // fall back to the always supported Xrgb8888 otherwise
-            for format in self.shm.formats() {
-                if let wl_shm::Format::Bgr888 = format {
-                    debug!("Using pixel format: {:?}", format);
-                    return *format
-                }
-                // XXX: One may add Rgb888 and HDR support here
-            }
-            debug!("Using default pixel format: Xrgb8888");
 
+            if !self.force_xrgb8888 {
+                // Consume less gpu memory by using Bgr888 if available,
+                // fall back to the always supported Xrgb8888 otherwise
+                for format in self.shm.formats() {
+                    if let wl_shm::Format::Bgr888 = format {
+                        debug!("Using pixel format: {:?}", format);
+                        return *format
+                    }
+                    // XXX: One may add Rgb888 and HDR support here
+                }
+            }
+
+            debug!("Using default pixel format: Xrgb8888");
             wl_shm::Format::Xrgb8888
         })
     }