From 6b16cc52dbfaa12889cadb93ce19da3e3fde46f2 Mon Sep 17 00:00:00 2001
From: Ivan Molodetskikh <yalterz@gmail.com>
Date: Tue, 17 Dec 2024 17:04:23 +0300
Subject: Add force-pipewire-invalid-modifier debug flag

---
 niri-config/src/lib.rs               |  2 ++
 src/niri.rs                          | 14 +++++++++++++-
 wiki/Configuration:-Debug-Options.md | 15 +++++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/niri-config/src/lib.rs b/niri-config/src/lib.rs
index f49c2496..a7ac89d2 100644
--- a/niri-config/src/lib.rs
+++ b/niri-config/src/lib.rs
@@ -1528,6 +1528,8 @@ pub struct DebugConfig {
     #[knuffel(child, unwrap(argument))]
     pub render_drm_device: Option<PathBuf>,
     #[knuffel(child)]
+    pub force_pipewire_invalid_modifier: bool,
+    #[knuffel(child)]
     pub emulate_zero_presentation_time: bool,
     #[knuffel(child)]
     pub disable_resize_throttling: bool,
diff --git a/src/niri.rs b/src/niri.rs
index b2e17d5d..336446b3 100644
--- a/src/niri.rs
+++ b/src/niri.rs
@@ -1486,6 +1486,8 @@ impl State {
 
     #[cfg(feature = "xdp-gnome-screencast")]
     pub fn on_screen_cast_msg(&mut self, msg: ScreenCastToNiri) {
+        use smithay::reexports::gbm::Modifier;
+
         use crate::dbus::mutter_screen_cast::StreamTargetId;
 
         match msg {
@@ -1560,13 +1562,23 @@ impl State {
                     }
                 };
 
-                let render_formats = self
+                let mut render_formats = self
                     .backend
                     .with_primary_renderer(|renderer| {
                         renderer.egl_context().dmabuf_render_formats().clone()
                     })
                     .unwrap_or_default();
 
+                {
+                    let config = self.niri.config.borrow();
+                    if config.debug.force_pipewire_invalid_modifier {
+                        render_formats = render_formats
+                            .into_iter()
+                            .filter(|f| f.modifier == Modifier::Invalid)
+                            .collect();
+                    }
+                }
+
                 let res = pw.start_cast(
                     gbm,
                     render_formats,
diff --git a/wiki/Configuration:-Debug-Options.md b/wiki/Configuration:-Debug-Options.md
index ee6691bc..66b449ff 100644
--- a/wiki/Configuration:-Debug-Options.md
+++ b/wiki/Configuration:-Debug-Options.md
@@ -17,6 +17,7 @@ debug {
     disable-cursor-plane
     disable-direct-scanout
     render-drm-device "/dev/dri/renderD129"
+    force-pipewire-invalid-modifier
     dbus-interfaces-in-non-session-instances
     wait-for-frame-completion-before-queueing
     emulate-zero-presentation-time
@@ -95,6 +96,20 @@ debug {
 }
 ```
 
+### `force-pipewire-invalid-modifier`
+
+<sup>Since: next release</sup>
+
+Forces PipeWire screencasting to use the invalid modifier, even when DRM offers more modifiers.
+
+Useful for testing the invalid modifier code path that is hit by drivers that don't support modifiers.
+
+```kdl
+debug {
+    force-pipewire-invalid-modifier
+}
+```
+
 ### `dbus-interfaces-in-non-session-instances`
 
 Make niri create its D-Bus interfaces even if it's not running as a `--session`.
-- 
cgit