Acoustics stage 1: mod plays near sounds when the engine muffles, band-energy check tool (#96 , fork patch 39)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-30 22:09:23 +03:00
42 changed files with 1848 additions and 40 deletions
@@ -192,6 +192,8 @@ struct PendingSound {
 const SOUND_SPEED: f64 = 17.15;
 /// Past this the far variant plays: muffled, more rolling echo.
 const FAR: f64 = 140.0;
+/// The same when the game's acoustics muffle (its tracing reaches 512 blocks).
+const ACOUSTIC_FAR: f64 = 480.0;

 /// Impulsive sounds (blasts, launches, shots, shock waves) come late from afar and have far variants.
 fn travels(event: &str) -> bool {
@@ -747,13 +749,16 @@ impl AirDef {
        let now = self.sim.tick;
        // Blasts play layered (cinema.rs), the nearest ones in full.
        let mut booms: Vec<(f64, usize, DVec3, f32, f32)> = Vec::new();
+        // The game muffles by walls and distance itself (#96): the near variants play out to the
+        // reach of its tracing, so nothing is muffled twice; past it the far ones still do.
+        let far = if render::acoustics() { ACOUSTIC_FAR } else { FAR };
        for (event, at, volume, pitch) in out.sounds {
            let dist = at.distance(self.listener);
            if let Some(power) = cinema::blast_power(event) {
                booms.push((dist, power, at, volume, pitch));
            } else if travels(event) {
                // Seen first, heard later; from afar muffled.
-                let name = if dist > FAR { format!("{event}_far") } else { event.to_string() };
+                let name = if dist > far { format!("{event}_far") } else { event.to_string() };
                let delay = (dist / SOUND_SPEED) as u64;
                if delay == 0 {
                    render::play_sound(&name, at.x, at.y, at.z, volume, pitch);
@@ -766,7 +771,7 @@ impl AirDef {
        }
        booms.sort_by(|a, b| a.0.total_cmp(&b.0));
        for (rank, (dist, power, at, volume, pitch)) in booms.into_iter().enumerate() {
-            for l in cinema::layers(power, dist, FAR, volume, pitch, rank) {
+            for l in cinema::layers(power, dist, far, volume, pitch, rank) {
                // Seen first, heard later: each voice after the sound has travelled.
                let delay = (dist / SOUND_SPEED) as u64 + l.delay;
                if delay == 0 {
@@ -11,6 +11,44 @@
 - Коммит из текста #96 (`76f680eb…`) в последних 200 коммитах `master` не нашёлся. Выводы привязаны к
  `453654ec`.

+## Статус
+
+**Стадия 1 (прямой звук) сделана**, включается `HORIZON_ACOUSTICS=1` (по умолчанию выключено, звук как был). Стадии 2-3
+не начаты. Коммит SPR прежний, `453654ec`; атрибуция: `horizon/crates/horizon-client/src/acoustics/THIRD_PARTY_SPR.md`.
+GPL-файл один: `acoustics/spr_occlusion.rs`; остальное (движок `acoustics.rs`, склейка `game/acoustics.rs`, DSP в `audio.rs`) наше.
+
+Что вышло и чем отличается от плана выше:
+
+- Фильтр голоса: не однополюсный lowpass, а **полка** (`audio::Occlusion`): ниже 1 кГц звук проходит с `gain`, выше с
+  `gain * cutoff`, два полюса, сглаживание 80 мс на буфер. Однополюсник резал бы и басы толстой стены; нужно «глухо», а не «тихо».
+- Формулы SPR: `cutoff = exp(-occ*3)`, `gain = cutoff^0.1`, 9 путей со сдвигом 0.35 (для 16 самых громких; остальные 1 путь),
+  блок источника не считается, неизвестный чанк = воздух, не полный блок x0.25. Луч — обход вокселей (свой), а не clip по формам:
+  забор, дверь считаются ячейкой целиком (x0.25). Жидкости пока не глушат.
+- Дальность 512 блоков (SPR: ~64), счёт клеток, не времени: 40 тыс. клеток на тик встроенно (новый звук, 1 путь, чтобы взрыв
+  не начинался «ярким»), 400 тыс. на задание рабочего потока (9 путей, одно задание за раз); при съёмке всё встроенно, 600 тыс.
+  клеток на тик. Порядок: по громкости, затем по id; сумма голосов в `mix` теперь тоже по id (раньше порядок HashMap делал дорожку
+  недетерминированной при нескольких голосах).
+- Кеш по ячейкам 2x2x2 источника и слушателя, 4096 записей; сброс по секциям `World.sound_changes` (как `mod_changes`),
+  по эпохе мира и при переполнении; результат задания, начатого до изменения в его коробке, отбрасывается.
+- Воздух: `0.994^расстояние` на верха (EFX по умолчанию, не проверено по OpenAL Soft) — иначе при `acoustics=on` пропадала бы
+  дальность, которую раньше давали `_far`-сэмплы.
+- Мод: API 21, `render.acoustics()`; при включённой акустике мод играет ближние варианты до 480 блоков (`ACOUSTIC_FAR`), дальше
+  `_far`. Задержку распространения мод держит сам (не трогали).
+- Реплей: мир, из которого читает акустика, — тот самый `World`, где реплей показывает блоки на нужный момент (журнал
+  изменений, `set-world-time-view`); перемотка пишет блоки через `put`/`set_block`, а они попадают в `sound_changes`. Значит
+  стена, которой уже нет, в реплее не глушит, а которая была — глушит. Проверено чтением кода, не запуском.
+
+Измерено (release, M-серия, `audio::tests::bench_one_hundred_voices_with_and_without_occlusion`, 100 голосов, буфер 512 кадров
+10.67 мс): 0.110 мс без акустики, 0.327 мс с полкой на всех (+0.217 мс, около 2% буфера); оценка 0.5-1 мс выше была завышена.
+
+Проверка без слуха (`audio::tests::export_wall_tracks` через настоящие `Acoustics` и `mix`, затем `tools/acoustics_check.py`),
+выстрел 1.5 с на 60 блоках, стена камня в 2 блока: ниже 300 Гц -5.2 дБ (SPR: gain 0.55), 300-1500 -7.4, 1500-5000 -19.7, выше 5000 -40.0 дБ.
+Тесты: `cargo test -p horizon-client --lib acoustics` (формулы, неизвестное, щель, кеш, инвалидация, детерминизм, рабочий поток) и `audio`.
+
+Не сделано / не проверено: запуск в игре и экспорт видео с настоящей сценой (склейка `game/acoustics.rs` — таблица состояний,
+снимок чанков — компилируется, но в игре не прогонялась); влияние на кадр при налёте; жидкости; дверь как проём (считается
+ячейкой); потолок памяти снимка. Стадии 2-3 (отводы эха, шины реверба) не начаты.
+
 ## 1. Как SPR идёт от источника к результату

 Сигнал: Minecraft вызывает `Channel.play` → `mixin/SourceMixin.play` → `SoundPhysics.onPlaySound` →
@@ -1,7 +1,7 @@
 From 3de7a6875140a107e28563cc44489b55f5794517 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 12:37:45 +0300
-Subject: [PATCH 01/38] Mod API (AirDef fork): world models, client particles,
+Subject: [PATCH 01/39] Mod API (AirDef fork): world models, client particles,
 sounds, ground heights

 render.set-models draws block models with an interpolated pose per id;
@@ -1,7 +1,7 @@
 From a6d64e6415bf618539af464e521091e72b72d72f Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 12:39:45 +0300
-Subject: [PATCH 02/38] cargo-horizon-mod: report particles and sounds
+Subject: [PATCH 02/39] cargo-horizon-mod: report particles and sounds

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
 ---
@@ -1,7 +1,7 @@
 From ee79b3562feebe51959a01f1585a9e85bd53ccb5 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 13:33:10 +0300
-Subject: [PATCH 03/38] Mod API (AirDef fork): full-screen post pass for mods
+Subject: [PATCH 03/39] Mod API (AirDef fork): full-screen post pass for mods

 render.set-post compiles a mod's WGSL after a prelude (camera matrices,
 time, 256 vec4 of params, the world's colour and depth) and runs it after
@@ -1,7 +1,7 @@
 From 2b137dbbedd540daeebc7f5e387847aeb56a1355 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 22:09:30 +0300
-Subject: [PATCH 04/38] Mod models: draw far models as scaled impostors past
+Subject: [PATCH 04/39] Mod models: draw far models as scaled impostors past
 the far plane, cull at 4096

 ---
@@ -1,7 +1,7 @@
 From c8ebca6e0af68630e65211844b34d25c5b985c03 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 22:31:00 +0300
-Subject: [PATCH 05/38] Mod cameras: render.set-views draws the world from
+Subject: [PATCH 05/39] Mod cameras: render.set-views draws the world from
 other points into pictures that HUD view shapes show (API level 9)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 8d2261fc4f8072c32e454139cfea7a8c0cd9d664 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 23:08:21 +0300
-Subject: [PATCH 06/38] Mods: more fuel per tick and per event (AirDef plans
+Subject: [PATCH 06/39] Mods: more fuel per tick and per event (AirDef plans
 raids)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 6c548de34def8e4a624d734243418090798bd16a Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Wed, 28 Oct 2026 23:25:29 +0300
-Subject: [PATCH 07/38] Mod cameras up to 1920x1080 (full-screen replays)
+Subject: [PATCH 07/39] Mod cameras up to 1920x1080 (full-screen replays)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
 ---
@@ -1,7 +1,7 @@
 From 9b9e93269d67401cc620567a884d5ce97f68d76e Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 11:15:11 +0300
-Subject: [PATCH 08/38] Mod cameras: distant terrain tiles, fog measured from
+Subject: [PATCH 08/39] Mod cameras: distant terrain tiles, fog measured from
 the camera, no impostors while one is shown

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 065d9fa02966238a5bd9ff460392a1a809db0b11 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 11:25:45 +0300
-Subject: [PATCH 09/38] Mods: game.world-id, so mods keep state per world (API
+Subject: [PATCH 09/39] Mods: game.world-id, so mods keep state per world (API
 level 9)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 1bf28135fd9a31f837323dc3a8d81ed73343d816 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 12:01:08 +0300
-Subject: [PATCH 10/38] cargo-horizon-mod: trial runs behind feature full, so a
+Subject: [PATCH 10/39] cargo-horizon-mod: trial runs behind feature full, so a
 packing-only tool skips wasmtime

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 0a56f5616df4699588cbcc529d4720661baa810f Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 13:18:43 +0300
-Subject: [PATCH 11/38] HD lighting: G-buffer pass, per-pixel mod point lights
+Subject: [PATCH 11/39] HD lighting: G-buffer pass, per-pixel mod point lights
 in HDR, bloom and tone curve; render.set-lights and render.set-lighting (API
 level 10)

@@ -1,7 +1,7 @@
 From 9ebf0031fe9ba6b7f02afb26e4fd3a1ba4ddb0d0 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 13:59:43 +0300
-Subject: [PATCH 12/38] HD lighting stage 2: sun and moon shadow cascades, the
+Subject: [PATCH 12/39] HD lighting stage 2: sun and moon shadow cascades, the
 world relit (sun by face angle and shadow, sky and block light through the
 lightmap), light shafts and halos, fog over it again, a light colour grade

@@ -1,7 +1,7 @@
 From 7a5a38f68923aec62f10bfa0df50b436474ed612 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 16:19:53 +0300
-Subject: [PATCH 13/38] HD: bind groups cached until a resize or a new source,
+Subject: [PATCH 13/39] HD: bind groups cached until a resize or a new source,
 shadow passes draw only the entities that cast shadows

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 8020811e57d4b5a9ea1cd72d30ce859dc5095d35 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 16:25:44 +0300
-Subject: [PATCH 14/38] HD: lights culled per 16x16 tile (surface and halo
+Subject: [PATCH 14/39] HD: lights culled per 16x16 tile (surface and halo
 lists built on the CPU), a naga test for the lighting shaders

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 72d3fddfea329e578162656151350f0aa2efd323 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 16:43:36 +0300
-Subject: [PATCH 15/38] HD: GPU time per pass in the F3 timing list,
+Subject: [PATCH 15/39] HD: GPU time per pass in the F3 timing list,
 half-resolution GTAO with a depth-aware blur

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 1fd83a821bf270879d8ece5aa583f200ed920d89 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:02:02 +0300
-Subject: [PATCH 16/38] HD: shadows draw only sun-facing quads and skip buried
+Subject: [PATCH 16/39] HD: shadows draw only sun-facing quads and skip buried
 sections, the far cascade every second frame; TAA (Halton jitter,
 reprojection by depth, YCoCg variance clipping) before bloom

@@ -1,7 +1,7 @@
 From 1502d359d599228fe0f44ce6b99a3fded2ac5ea0 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:02:02 +0300
-Subject: [PATCH 17/38] Mods: model handles (render.model-id, model-generation,
+Subject: [PATCH 17/39] Mods: model handles (render.model-id, model-generation,
 set-models-by-id; API level 11) so mods send no model names each tick;
 clear-post and set-lighting documented

@@ -1,7 +1,7 @@
 From 0f9d99b8ad3e4b72e621d84c2396cf1d3d2b7a33 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:19:57 +0300
-Subject: [PATCH 18/38] HD: temporal upscaling (HORIZON_HD_SCALE: world,
+Subject: [PATCH 18/39] HD: temporal upscaling (HORIZON_HD_SCALE: world,
 G-buffer and lighting at a lower size, rebuilt to the window in the TAA
 pass); fix flickering shadows near the player (the near cascade lost its
 sections on frames the far one was held, the held far matrix ignored the
@@ -1,7 +1,7 @@
 From 38250c4392e27d5700842ca6ee47291dd1831b72 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:47:52 +0300
-Subject: [PATCH 19/38] HD water: its own pass (colour, normal, depth), the
+Subject: [PATCH 19/39] HD water: its own pass (colour, normal, depth), the
 floor under it lit, a composite with world-space waves, refraction with depth
 absorption in the biome colour, screen-space reflections, Fresnel and a
 shadowed sun glint (HORIZON_HD_WATER=0 to switch off)
@@ -1,7 +1,7 @@
 From dbc6f8a6e9c2eeabe1de15f1794013c90be7faa5 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 17:56:04 +0300
-Subject: [PATCH 20/38] HD water: no vanilla texture on the surface (the biome
+Subject: [PATCH 20/39] HD water: no vanilla texture on the surface (the biome
 colour only), a darker, deeper colour

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 13e74537dd6e63482e3613e0e416de1158944dfe Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 18:38:19 +0300
-Subject: [PATCH 21/38] HD sky and light: a physical atmosphere (Rayleigh, Mie,
+Subject: [PATCH 21/39] HD sky and light: a physical atmosphere (Rayleigh, Mie,
 ozone; constants and transmittance after Photon, MIT) for the sky, haze, fog
 and water reflections; warmer sunlight from the atmosphere's transmittance, a
 gentle sky-coloured ambient, soft PCSS-lite shadows near the player, a haze
@@ -1,7 +1,7 @@
 From 6277e051a89c2537570982f6ef275887193c05cf Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 19:02:16 +0300
-Subject: [PATCH 22/38] HD water: a darker blue, a little clearer, ripples a
+Subject: [PATCH 22/39] HD water: a darker blue, a little clearer, ripples a
 little higher

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 982265d21bb9d74ec0040db03feb5a55762286ad Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 21:41:48 +0300
-Subject: [PATCH 23/38] HD: Photon-style sunsets (Rec. 2020 atmosphere, sun
+Subject: [PATCH 23/39] HD: Photon-style sunsets (Rec. 2020 atmosphere, sun
 tint, blue hour; MIT), volumetric clouds with ground shadows instead of
 vanilla's in HD, volumetric fog with sun shafts and morning mist
 (HORIZON_HD_CLOUDS=0, HORIZON_HD_VOLFOG=0)
@@ -1,7 +1,7 @@
 From 24971b3c67d8c87673eb2e0d204cedf8a2f46d1c Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 21:43:22 +0300
-Subject: [PATCH 24/38] Mods: world queries for simulations (render.query-rays,
+Subject: [PATCH 24/39] Mods: world queries for simulations (render.query-rays,
 query-sections, world-changes; API level 12): block-exact rays and section
 occupancy by collision, sight or sound, answered next tick within budgets,
 and a log of changed sections
@@ -1,7 +1,7 @@
 From fdec4960983bdff82f3793460f9a5234f0cd3f49 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 22:56:15 +0300
-Subject: [PATCH 25/38] HD fixes: rain level from the world not from rain
+Subject: [PATCH 25/39] HD fixes: rain level from the world not from rain
 geometry (#41), TAA history on the jittered grid (#38), vanilla cloud tint
 without a depth heuristic (#35), air fog once over water (#37), translucent
 things in front of HD water (#36), cheaper sunrise fan (#39), halos in thick
@@ -1,7 +1,7 @@
 From 21391afb26f49505d6cdaf454a6355cd4e747503 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 23:19:53 +0300
-Subject: [PATCH 26/38] HD split into modules (gfx/hd/: one Rust file and one
+Subject: [PATCH 26/39] HD split into modules (gfx/hd/: one Rust file and one
 WGSL file per pass, a shared prelude), contracts for colour, depth, alpha,
 time and coordinates written down, tests that the frame layout and bindings
 match between Rust and WGSL (#45)
@@ -1,7 +1,7 @@
 From 8d4cadbf8534309ac847d34e229f6d764770475d Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Thu, 29 Oct 2026 23:22:19 +0300
-Subject: [PATCH 27/38] HD clouds: noise scales that divide the camera's
+Subject: [PATCH 27/39] HD clouds: noise scales that divide the camera's
 65536-block wrap, so the clouds and their shadows no longer jump at x or z =
 0

@@ -1,7 +1,7 @@
 From 0fb59c782abf269fe555faa3241b31acf41e26d7 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 03:17:11 +0300
-Subject: [PATCH 28/38] HD: volumetric smoke and missile trails with clear
+Subject: [PATCH 28/39] HD: volumetric smoke and missile trails with clear
 tunnels through fog and cloud (render.set-smoke, API level 14; #54); sun
 speculars by material, wet surfaces and puddles in rain, wind in foliage
 (HORIZON_HD_SPECULAR=0, HORIZON_HD_WIND=0, HORIZON_HD_SMOKE=0); HD shaders
@@ -1,7 +1,7 @@
 From e4bc29da45d0d38244c6eb2ba3ffb9ab853540c0 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 03:26:09 +0300
-Subject: [PATCH 29/38] HD clouds composited by depth so terrain and vehicles
+Subject: [PATCH 29/39] HD clouds composited by depth so terrain and vehicles
 inside or behind the layer are hidden and those in front stay in front (#67);
 world-anchored noise everywhere (cloud detail by height above the layer, fog,
 smoke and puddle scales dividing the wrap) (#68); the replay's time is visual
@@ -1,7 +1,7 @@
 From 20f699796afb12b600236a4e8859cd97430f86f0 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 03:44:45 +0300
-Subject: [PATCH 30/38] HD smoke: young trails drawn at least as wide as a grid
+Subject: [PATCH 30/39] HD smoke: young trails drawn at least as wide as a grid
 cell (density scaled to keep the mass), gentler bulges, so a trail is a
 smooth ribbon and not a chain of puffs

@@ -1,7 +1,7 @@
 From 35ffbaa26dd91855c8b93446646ba8c58448d3d0 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 03:59:41 +0300
-Subject: [PATCH 31/38] Mods: render.set-main-view (API level 15) renders the
+Subject: [PATCH 31/39] Mods: render.set-main-view (API level 15) renders the
 screen's world from a mod camera with the full pipeline, so replays get HD
 and the post effects; small mod views get the post pass with their own camera

@@ -1,7 +1,7 @@
 From 27e24527550942695164dd3a769a42a659e797ca Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 09:28:05 +0300
-Subject: [PATCH 32/38] Spot lights for mods (render.set-spot-lights, API level
+Subject: [PATCH 32/39] Spot lights for mods (render.set-spot-lights, API level
 16): surfaces lit in the cone, a volumetric beam stopped by depth (#60); film
 capture (render.capture-*, set-film-quality, API level 17): fixed-step clock,
 frames piped to ffmpeg or PNGs, offline audio, no chat in the frames (#58);
@@ -1,7 +1,7 @@
 From 615f5c3fa7c19a9895f8972a88333c6f250ad78a Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 14:30:39 +0300
-Subject: [PATCH 33/38] HD clouds and fog polish: cloud panorama, cirrus,
+Subject: [PATCH 33/39] HD clouds and fog polish: cloud panorama, cirrus,
 terrain-aware fog, far smoke cascade; replay world log and film clock;
 material overlays by sprite name

@@ -1,7 +1,7 @@
 From 0254984fdcce53a4a0f2bff15f9be3b78c93842e Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 15:01:09 +0300
-Subject: [PATCH 34/38] HD: coloured sun through glass and leaves, rain ripples
+Subject: [PATCH 34/39] HD: coloured sun through glass and leaves, rain ripples
 on water, film motion blur and depth of field

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 9645d3f1f47d8bb358d5630288bdd801bd874911 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 15:19:32 +0300
-Subject: [PATCH 35/38] Film export: every frame in flight reaches the writer,
+Subject: [PATCH 35/39] Film export: every frame in flight reaches the writer,
 listener follows the main view, cloud wind on film frames, set-smoke reports
 real activity

@@ -1,7 +1,7 @@
 From 22d6835507d5627b0fe4a749b082b025b35e0262 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 15:43:11 +0300
-Subject: [PATCH 36/38] Mod command trees: command.set-tree and
+Subject: [PATCH 36/39] Mod command trees: command.set-tree and
 set-suggestions, typed parse, colouring and completion from one tree (API 19)

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -1,7 +1,7 @@
 From 9be21a54fff055e78db245488c28a971a823fdba Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 16:10:23 +0300
-Subject: [PATCH 37/38] Persistent mod sound sources: start, update, stop with
+Subject: [PATCH 37/39] Persistent mod sound sources: start, update, stop with
 generations, click-free voices, loop sections, voice budget and virtual loops
 (API 20)

@@ -1,7 +1,7 @@
 From e84cdc21a9fabc4518c18edbeacb2df24c85b983 Mon Sep 17 00:00:00 2001
 From: chexit <chexit@duck.com>
 Date: Fri, 30 Oct 2026 19:07:37 +0300
-Subject: [PATCH 38/38] HD clouds: rays from a far point, so the view bob's eye
+Subject: [PATCH 38/39] HD clouds: rays from a far point, so the view bob's eye
 offset does not bend them

 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Проверка акустики без слуха (#96): энергия по полосам в дорожке с преградой и без неё.
+
+    python3 tools/acoustics_check.py open.raw wall.raw            # s16le, 48000 Гц, стерео
+    python3 tools/acoustics_check.py open.raw wall.raw --rate 48000 --channels 2
+
+Дорожки берутся из `Audio::film_mix` (экспорт видео пишет `<имя>.audio.raw`) или из теста
+`cargo test -p horizon-client --lib audio::tests::export_wall_tracks -- --ignored` (HORIZON_ACOUSTICS_OUT=папка).
+Для каждой дорожки считается энергия левого канала в четырёх полосах (до 300 Гц, 300-1500, 1500-5000, выше
+5000) и разница в дБ между дорожками. Преграда должна срезать верхи (выше 5 кГц не меньше чем на 15 дБ) и
+оставить низы (до 300 Гц теряют не больше 8 дБ). Коды выхода: 0 — в порогах, 1 — нет, 2 — ошибка аргументов.
+Только стандартная библиотека.
+"""
+import argparse
+import array
+import cmath
+import math
+import sys
+
+BANDS = [("<300", 0, 300), ("300-1500", 300, 1500), ("1500-5000", 1500, 5000), (">5000", 5000, 1e9)]
+
+
+def fft(a):
+    n = len(a)
+    if n == 1:
+        return a
+    even, odd = fft(a[0::2]), fft(a[1::2])
+    t = [cmath.exp(-2j * math.pi * k / n) * odd[k] for k in range(n // 2)]
+    return [even[k] + t[k] for k in range(n // 2)] + [even[k] - t[k] for k in range(n // 2)]
+
+
+def bands(path, rate, channels):
+    raw = array.array("h")
+    with open(path, "rb") as f:
+        data = f.read()
+    raw.frombytes(data[: len(data) // 2 * 2])
+    left = [s / 32768.0 for s in raw[0::channels]]
+    n = 1
+    while n * 2 <= len(left):
+        n *= 2
+    n = min(n, 1 << 16)
+    if n < 1024:
+        sys.exit(f"{path}: too short ({len(left)} frames)")
+    # A Hann window over the loudest n frames' start: the burst is at the start of the track.
+    w = [left[i] * (0.5 - 0.5 * math.cos(2 * math.pi * i / (n - 1))) for i in range(n)]
+    spec = fft([complex(v) for v in w])
+    out = [0.0] * len(BANDS)
+    for k in range(1, n // 2):
+        hz = k * rate / n
+        for i, (_, lo, hi) in enumerate(BANDS):
+            if lo <= hz < hi:
+                out[i] += abs(spec[k]) ** 2
+    return out
+
+
+def db(a, b):
+    return 10 * math.log10(max(a, 1e-20) / max(b, 1e-20))
+
+
+def main():
+    p = argparse.ArgumentParser(description=__doc__.split("\n")[0])
+    p.add_argument("open")
+    p.add_argument("wall")
+    p.add_argument("--rate", type=int, default=48000)
+    p.add_argument("--channels", type=int, default=2)
+    p.add_argument("--min-high-cut", type=float, default=15.0, help="dB the band above 5 kHz must drop")
+    p.add_argument("--max-low-loss", type=float, default=8.0, help="dB the band below 300 Hz may drop")
+    a = p.parse_args()
+    o, w = bands(a.open, a.rate, a.channels), bands(a.wall, a.rate, a.channels)
+    print(f"{'band, Hz':>10} {'open dB':>9} {'wall dB':>9} {'change dB':>10}")
+    ref = max(o)
+    for (name, _, _), x, y in zip(BANDS, o, w):
+        print(f"{name:>10} {db(x, ref):9.1f} {db(y, ref):9.1f} {db(y, x):10.1f}")
+    low, high = db(w[0], o[0]), db(w[-1], o[-1])
+    ok = high <= -a.min_high_cut and low >= -a.max_low_loss
+    print(f"highs {high:.1f} dB (need <= -{a.min_high_cut}), lows {low:.1f} dB (need >= -{a.max_low_loss}): {'ok' if ok else 'FAIL'}")
+    return 0 if ok else 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())