Minimap: time frames from tick column (t column is non-monotonic across pauses)

src/lib/api/world.ts

@@ -37,7 +37,7 @@ function chunkBaseUrl(chunk: PreviewChunk): string {
 }
 
 type TickRow = {
-	t: number;
+	tick: number;
 	x: number;
 	y: number;
 	z: number;
@@ -48,6 +48,9 @@ type TickRow = {
 	is_alive: boolean;
 };
 
+// CS2 demo tickrate.
+const TICK_RATE = 64;
+
 async function loadChunkFrames(
 	chunk: PreviewChunk,
 	player: number,
@@ -55,15 +58,21 @@ async function loadChunkFrames(
 ): Promise<WorldFrame[]> {
 	const base = chunkBaseUrl(chunk);
 	const rows = await fetchParquetRows<TickRow>(`${base}/ticks.parquet`, opts);
+	if (!rows.length) return [];
 
 	const steamid = `slot-${player}`;
 	const name = `Player ${player}`;
+	// The ticks.parquet `t` column can be non-monotonic (it resets across
+	// tactical-pause segments), which breaks the binary search in snapshotAt.
+	// `tick` is the absolute demo tick counter and stays monotonic across the
+	// whole round, so derive round-relative time from it.
+	const tick0 = rows[0].tick;
 
 	const frames: WorldFrame[] = new Array(rows.length);
 	for (let i = 0; i < rows.length; i++) {
 		const r = rows[i];
 		frames[i] = {
-			t: r.t,
+			t: (r.tick - tick0) / TICK_RATE,
 			player,
 			steamid,
 			name,