beer

diff --git a/src/render.rs b/src/render.rsindex 19baab8..a449b63 100644--- a/src/render.rs+++ b/src/render.rs@@ -12,7 +12,7 @@ use crate::grid::{Cell, Color, CursorShape, Flags, Grid, Underline}; const DEFAULT_FG: Rgb = Rgb(0xc5, 0xc8, 0xc6); const DEFAULT_BG: Rgb = Rgb(0x18, 0x18, 0x18); -#[derive(Clone, Copy)]+#[derive(Clone, Copy, PartialEq, Eq)] struct Rgb(u8, u8, u8);  /// A mutable view over a BGRA pixel buffer.@@ -30,15 +30,29 @@ impl Canvas<'_> {         Some((y as usize * self.width + x as usize) * 4)     } +    /// Fill the whole buffer with one colour (fast path, no per-pixel bounds+    /// checks).+    fn clear(&mut self, c: Rgb) {+        let bytes = [c.2, c.1, c.0, 0xff];+        for px in self.pixels.chunks_exact_mut(4) {+            px.copy_from_slice(&bytes);+        }+    }+     fn fill_rect(&mut self, x0: i32, y0: i32, w: u32, h: u32, c: Rgb) {-        for dy in 0..h as i32 {-            for dx in 0..w as i32 {-                if let Some(i) = self.index(x0 + dx, y0 + dy) {-                    self.pixels[i] = c.2;-                    self.pixels[i + 1] = c.1;-                    self.pixels[i + 2] = c.0;-                    self.pixels[i + 3] = 0xff;-                }+        let x_start = x0.max(0) as usize;+        let x_end = ((x0 + w as i32).max(0) as usize).min(self.width);+        let y_start = y0.max(0) as usize;+        let y_end = ((y0 + h as i32).max(0) as usize).min(self.height);+        if x_start >= x_end {+            return;+        }+        let bytes = [c.2, c.1, c.0, 0xff];+        for y in y_start..y_end {+            let row =+                &mut self.pixels[(y * self.width + x_start) * 4..(y * self.width + x_end) * 4];+            for px in row.chunks_exact_mut(4) {+                px.copy_from_slice(&bytes);             }         }     }@@ -109,15 +123,19 @@ impl Renderer {             width,             height,         };-        canvas.fill_rect(0, 0, width as u32, height as u32, DEFAULT_BG);+        canvas.clear(DEFAULT_BG);          let m = self.fonts.metrics(); +        // Cell backgrounds: only paint cells that differ from the cleared+        // default - most of a screen is default background.         for y in 0..grid.rows() {             for x in 0..grid.cols() {                 let (_, bg) = cell_colors(grid.cell(x, y));-                let (px, py) = (x as i32 * m.width as i32, y as i32 * m.height as i32);-                canvas.fill_rect(px, py, m.width, m.height, bg);+                if bg != DEFAULT_BG {+                    let (px, py) = (x as i32 * m.width as i32, y as i32 * m.height as i32);+                    canvas.fill_rect(px, py, m.width, m.height, bg);+                }             }         } diff --git a/src/wayland.rs b/src/wayland.rsindex cc2aa33..7dc09b9 100644--- a/src/wayland.rs+++ b/src/wayland.rs@@ -6,7 +6,6 @@ use std::os::fd::OwnedFd; use std::os::unix::process::ExitStatusExt; use std::process::ExitCode;-use std::time::Duration;  use anyhow::Context; use calloop::generic::Generic;@@ -105,9 +104,11 @@ pub fn run() -> anyhow::Result<ExitCode> {         exit_code: ExitCode::SUCCESS,     }; +    // Block until an event (PTY output, input, configure) arrives - every+    // repaint is driven by one, so there is nothing to do on a timer.     while !app.exit {         event_loop-            .dispatch(Duration::from_millis(16), &mut app)+            .dispatch(None, &mut app)             .context("dispatch event loop")?;         if app.dirty {             app.draw();