tty: coalesce queued input events into one frame; tracy zones behind -Dtracy

The tty shell rendered (core.render + full vaxis repaint + tree-sitter
re-highlight of the visible window) after EVERY event, so a wheel flick over a
highlighted file was 150 re-parses and 150 terminal repaints; the gui shell
drains the SDL queue before drawing and never had the issue. Now the tty loop
applies every queued input event, then renders once (batch cap 64; pty output
keeps a frame per chunk so progress paints and transient-state waits behave
exactly as before). Measured with tracy on a 2400-line .zig scroll script:
150 highlightFileRange calls at 1.85ms mean -> 4; render pipeline total
730ms -> 64ms; 364 frames -> 39. Snap suite 18/18.

Tracy: -Dtracy=<path-to-tracy-checkout> compiles TracyClient.cpp into the
binary and turns src/tracy.zig zones live (default off, all no-ops). Sampling,
callstacks, system tracing and the crash handler are disabled: tracy's symbol
worker SIGSEGVs on this binary's debug info and its crash handler then parks
every thread before the first frame. Capture: tracy-capture -o t.tracy; export:
tracy-csvexport t.tracy.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index c4893b25..63943c04 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -14,6 +14,7 @@ const uucode = @import("uucode");
 const modal = @import("modal.zig");
 const look = @import("look.zig");
 const syntax = @import("syntax.zig");
+const tracy = @import("tracy.zig");
 pub const image = @import("image.zig");
 pub const dump = @import("dump.zig");
 
@@ -3077,6 +3078,8 @@ pub const Pardes = struct {
     /// re-highlight the visible window of any file whose syntax went stale
     /// (edit, scroll, load) — visible-range-first so big files stay snappy
     fn refreshDirtyHighlights(p: *Pardes) void {
+        const tz = tracy.zone(@src(), "refreshDirtyHighlights");
+        defer tz.end();
         for (p.panes) |slot| {
             const pane = slot orelse continue;
             if (pane.file == null) continue;
@@ -3226,6 +3229,8 @@ pub const Pardes = struct {
     }
 
     fn renderPane(p: *Pardes, arena: std.mem.Allocator, pane: *Pane, r: Rect, active: bool) !void {
+        const tz = tracy.zone(@src(), "renderPane");
+        defer tz.end();
         if (r.w <= GUTTER or r.h == 0) return;
         const s = &p.surface;
         const th = p.theme();
@@ -3278,7 +3283,9 @@ pub const Pardes = struct {
             .fg = if (th.fg) |c| .{ .rgb = c } else .default,
             .bg = if (th.bg) |c| .{ .rgb = c } else .default,
         };
+        const tz_body = tracy.zone(@src(), "bodyText");
         const body = try p.bodyText(arena, pane);
+        tz_body.end();
         var it = std.mem.splitScalar(u8, body, '\n');
         var i: u16 = 0;
         while (it.next()) |line| : (i += 1) {
@@ -3303,6 +3310,8 @@ pub const Pardes = struct {
         // tree-sitter style byte; content starts after the lineno gutter
         if (p.colors_on) if (pane.file) |*f| {
             if (f.highlights.len > 0) {
+                const tz_recolor = tracy.zone(@src(), "synRecolor");
+                defer tz_recolor.end();
                 var flines = std.mem.splitScalar(u8, f.content, '\n');
                 var skip: usize = 0;
                 while (skip < f.scroll) : (skip += 1) {