cleanup

src/capture.rs

@@ -7,12 +7,14 @@
 //!
 //! The pixels are never mapped into this process. A capture buffer goes straight
 //! to a subsurface for display, so the compositor writes those pages and samples
-//! them again itself.
+//! them again itself. Live previews are always on.
 
 use std::error::Error;
 use std::os::fd::AsFd;
 use std::time::{Duration, Instant};
 
+use crate::Target;
+
 use wayland_client::protocol::{
     wl_buffer::{self, WlBuffer},
     wl_callback, wl_output, wl_shm,
@@ -30,29 +32,7 @@ use wayland_protocols::wp::viewporter::client::wp_viewport::WpViewport;
 
 use crate::app::App;
 use crate::shm;
-use crate::target::{Kind, Target};
-
-/// Which tiles keep updating after the first frame.
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum Live {
-    /// Every tile.
-    All,
-    /// Only the selected tile: much cheaper, and still reads as alive.
-    Current,
-    /// Nothing: one snapshot each, a picker rather than an expose.
-    None,
-}
-
-impl Live {
-    pub fn parse(s: &str) -> Result<Self, String> {
-        match s.trim() {
-            "all" => Ok(Live::All),
-            "current" => Ok(Live::Current),
-            "none" => Ok(Live::None),
-            other => Err(format!("{other:?} is not all, current or none")),
-        }
-    }
-}
+use crate::target::Kind;
 
 /// One capture buffer. `busy` means the compositor still holds it — either it is
 /// on screen or a capture is writing into it — so we must not scribble over it.
@@ -202,9 +182,8 @@ impl App {
                 tile.settled = true;
                 continue;
             }
-            // Only a tile that will be re-captured needs a second buffer, and a
-            // display's is the size of the whole screen.
-            let slots = if self.live == Live::None || tile.target.kind == Kind::Output {
+            // Always 2 buffers for live preview; display gets full-screen buffer.
+            let slots = if tile.target.kind == Kind::Output {
                 1
             } else {
                 2
@@ -301,9 +280,6 @@ impl App {
     /// Ask for the next frame callback. A commit is needed for the compositor to
     /// schedule one, and an empty commit is enough.
     pub fn arm_frame_callback(&mut self, qh: &QueueHandle<Self>) {
-        if self.live == Live::None {
-            return;
-        }
         if let Some(surface) = self.surface.clone() {
             surface.frame(qh, ());
             surface.commit();
@@ -314,15 +290,9 @@ impl App {
     /// the overlay is not being presented.
     pub fn tick(&mut self, qh: &QueueHandle<Self>) {
         self.stats.ticks += 1;
-        if self.live == Live::None {
-            return;
-        }
         let interval = Duration::from_secs_f64(1.0 / self.fps.max(1) as f64);
         let now = Instant::now();
         for i in 0..self.tiles.len() {
-            if self.live == Live::Current && i != self.sel {
-                continue;
-            }
             // A display tile shows this overlay, which shows the display tile:
             // refreshing it never settles and costs a whole screen per frame.
             if self.tiles[i].target.kind == Kind::Output {