export_dmabuf: Initial support

src/backend/kms/mod.rs

@@ -52,7 +52,7 @@ use std::{
     collections::{HashMap, HashSet},
     path::PathBuf,
     rc::Rc,
-    time::Duration,
+    time::{Duration, Instant},
 };
 
 mod drm_helpers;
@@ -86,6 +86,7 @@ pub struct Surface {
     surface: Option<GbmBufferedSurface<Rc<RefCell<GbmDevice<SessionFd>>>, SessionFd>>,
     connector: connector::Handle,
     output: Output,
+    last_render: Option<(Dmabuf, Instant)>,
     last_submit: Option<DrmEventTime>,
     refresh_rate: u32,
     vrr: bool,
@@ -679,6 +680,7 @@ impl Device {
             vrr,
             refresh_rate,
             last_submit: None,
+            last_render: None,
             pending: false,
             render_timer_token: None,
             #[cfg(feature = "debug")]
@@ -755,7 +757,7 @@ impl Surface {
             .with_context(|| "Failed to allocate buffer")?;
 
         renderer
-            .bind(buffer)
+            .bind(buffer.clone())
             .with_context(|| "Failed to bind buffer")?;
 
         match render::render_output(
@@ -769,6 +771,7 @@ impl Surface {
             Some(&mut self.fps),
         ) {
             Ok(_) => {
+                self.last_render = Some((buffer, Instant::now()));
                 surface
                     .queue_buffer()
                     .with_context(|| "Failed to submit buffer for display")?;
@@ -1008,4 +1011,14 @@ impl KmsState {
         }
         Ok(())
     }
+
+    pub fn capture_output(&self, output: &Output) -> Option<(DrmNode, Dmabuf, Instant)> {
+        self.devices
+            .values()
+            .find_map(|dev| dev.surfaces.values().find(|s| &s.output == output)
+                .and_then(|s| s.last_render.clone()
+                    .map(|(buf, time)| (dev.render_node.clone(), buf, time))
+                )
+            )
+    }
 }

src/backend/render/mod.rs

@@ -35,7 +35,7 @@ use smithay::{
     wayland::{output::Output, shell::wlr_layer::Layer as WlrLayer},
 };
 
-mod cursor;
+pub mod cursor;
 use self::cursor::PointerElement;
 
 pub type GlMultiRenderer<'a> =
@@ -152,6 +152,33 @@ pub fn render_output<R>(
     hardware_cursor: bool,
     #[cfg(feature = "debug")] mut fps: Option<&mut Fps>,
 ) -> Result<Option<Vec<Rectangle<i32, Physical>>>, RenderError<R>>
+where
+    R: Renderer + ImportAll + AsGles2Renderer,
+    <R as Renderer>::TextureId: Clone + 'static,
+    CustomElem: RenderElement<R>,
+{
+    let workspace = state.shell.active_space(output).idx;
+    render_workspace(
+        gpu,
+        renderer,
+        age,
+        state,
+        workspace,
+        output,
+        hardware_cursor,
+    )
+}
+
+pub fn render_workspace<R>(
+    gpu: Option<&DrmNode>,
+    renderer: &mut R,
+    age: u8,
+    state: &mut Common,
+    space_idx: u8,
+    output: &Output,
+    hardware_cursor: bool,
+    #[cfg(feature = "debug")] mut fps: Option<&mut Fps>,
+) -> Result<Option<Vec<Rectangle<i32, Physical>>>, RenderError<R>>
 where
     R: Renderer + ImportAll + AsGles2Renderer,
     <R as Renderer>::TextureId: Clone + 'static,
@@ -161,8 +188,11 @@ where
     if let Some(ref mut fps) = fps {
         fps.start();
     }
-    let workspace = state.shell.active_space(output);
+
+    let space_idx = space_idx as usize;
+    let workspace = &mut state.shell.spaces[space_idx];
     let maybe_fullscreen_window = workspace.get_fullscreen(output).cloned();
+
     let res = if let Some(window) = maybe_fullscreen_window {
         #[cfg(not(feature = "debug"))]
         {
@@ -175,11 +205,11 @@ where
     } else {
         #[cfg(not(feature = "debug"))]
         {
-            render_desktop(gpu, renderer, age, state, output, hardware_cursor)
+            render_desktop(gpu, renderer, age, state, space_idx, output, hardware_cursor)
         }
         #[cfg(feature = "debug")]
         {
-            render_desktop(gpu, renderer, age, state, output, hardware_cursor, fps.as_deref_mut())
+            render_desktop(gpu, renderer, age, state, space_idx, output, hardware_cursor, fps.as_deref_mut())
         }
     };
 
@@ -196,6 +226,7 @@ fn render_desktop<R>(
     renderer: &mut R,
     age: u8,
     state: &mut Common,
+    space_idx: usize,
     output: &Output,
     hardware_cursor: bool,
     #[cfg(feature = "debug")] fps: Option<&mut Fps>,
@@ -209,7 +240,7 @@ where
 
     #[cfg(feature = "debug")]
     {
-        let workspace = state.shell.active_space(output);
+        let workspace = &state.shell.spaces[space_idx];
         let output_geo = workspace
             .space
             .output_geometry(output)
@@ -268,7 +299,7 @@ where
         }
     }
 
-    state.shell.active_space_mut(output).space.render_output(
+    state.shell.spaces[space_idx].space.render_output(
         renderer,
         &output,
         age as usize,