0.2.6-dev: DESIGN §31.6 impostor bounds and slot clearing (#542: seen, cause, now, cost, [ASSUMED], tests), docs/design/client.md describes the impostor box and slot clipping, CHANGELOG 0.2.6-dev 界面 credits @ImPQlc; golden: unchanged

docs/design/client.md

@@ -42,7 +42,7 @@ view.resize() ; view.destroy()
 
 Asset URLs (0.2.6, host bandwidth layer 1): the client takes every art, model and audio URL from `data/assets.json` and `data/local-assets.json` and builds none itself, so the content-hash segment the server puts in front (`/assets/~<hash>/…`, docs/ASSETS.md "The committed manifest and the served manifests") needs nothing on this side: `validSpine` still sees `.skel`, pixi-spine finds the atlas and its pages under the same segment (a model shares one hash), audio is fetched as `/media/~<hash>/…`. The two URLs the client derives from another file's — the 3D board's `tiles.json` beside the atlas and the token death sound beside `charDie` — are served `no-cache` (the board) or drop the segment (`shared/assetPaths.js unhashedUrl`, the sound).
 
-Visuals: oblique perspective board (tilted ~30°, trapezoid tiles), raised highland blocks with side faces, road/floor/forbidden styles per research 07 §7, pulsing red gates, blue objective, dashed hand pads. Units: Spine (Front/Back rule, feet anchored — flying units hover `FLY_HOVER` 1.3 tiles up, the client's 0.35 in character space, research 12, §25.13.5 — an enemy flyer from the road whatever tile it crosses (GitHub #277) —, shadow sprite on the ground), elite gold outline glow, tier chip, HP bar (green ally / red enemy), SP bar (skill ready glow; while an ammo skill runs it is the magazine instead — a yellow cell per round, emptying from the right, `b.snap ammo`, and the skill draws no standing aura, UnitInfo `ammoSkill`), 斩业星熊's 我执 pool as a red bar over her drained HP bar (`b.snap neg`), 伺夜's 狼群 count as a row of diamonds under the bars, the lit ones the 狼影 left (`b.snap wolves`; 0.2.2, GitHub PR #303 / #378 / #383), status icons, the element gauge row under the bars — icon + white bar of the remaining 元素值, element-coloured refill during a 爆发冷却 (§18.3, §20.8); enemies drawn × their official prefab factor (enemies.json `modelScale`, §20.4); an enemy's mode — the `form` of a sim fx (`shared/protocol.js fxForm`), or UnitInfo `form` for a view built later through `render/app/info.js renderInfo` — switches clip sets (`render/units.js FORMS`: 掠海漂移体 crawl, 暴鸰 bombed, 转译基底's forms, the 逐火 embers, the leaders' 重生, 守墓石像, the 孤岛风云 prisoners' warning and 解放; closing clips timed from the fx `dur`), a one-off cast (`PROJ[kind].once`) plays once, and a local-only model's web alias is tinted (`ALIAS_TINT`: 灼热 / 炽焰源石虫, §21.14); damage numbers (phys orange-white, arts purple, true white, heal green); projectiles drawn per kind, hit sparks and melee slashes, skill activation bursts and auras (§17.3); death fade for enemies, summons and devices — a knocked-out operator stays on its tile in its held Die pose under a redeploy ring (§18.3); leak flash at the objective. Fallback when Spine missing/failed: avatar in a rarity-coloured diamond with bob/lunge tweens — a failed or timed-out model is loaded again (bounded), and a view re-resolves its model and avatar when the asset manifest arrives late or the tab is shown again (§21.27). 60 fps target with ≤ 120 units (a crowd draws its Spine units through the cached atlas, `render/impostor.js`, each refreshed every k-th frame: the refresh turns follow this frame's update order — `ctx.impostorSlot()`, a counter reset at the start of every frame — so a frame refreshes ⌊n/k⌋ or ⌈n/k⌉ of n units instead of whatever random per-unit phases gave, and a unit not refreshed for 2k frames is refreshed regardless; GitHub PR #334 by @Cloudnyco, issue #327 step 1 — its step 2, a time budget by priority, is not done; a model whose pose cannot change — `SpineActor.poseHeld()`: a knocked-out operator in the held end of its Die clip, a frozen model — is neither re-posed nor redrawn, only its clock runs, until a new clip, a revive, a wind-up, a form's closing clip, a clipping switch or a zoom past the impostor's rescale threshold; the redeploy rings draw one shared rasterised label per number, `render/textures.js downLabel`, the same pixels as a Text of their own). Picking (which unit a press / hover / dropped item is on) and the drag target follow one rule, `render/pick.js` — the tile under the pointer (§18.1); the Spine store never hands out a skeleton whose unload is in flight (§17.1).
+Visuals: oblique perspective board (tilted ~30°, trapezoid tiles), raised highland blocks with side faces, road/floor/forbidden styles per research 07 §7, pulsing red gates, blue objective, dashed hand pads. Units: Spine (Front/Back rule, feet anchored — flying units hover `FLY_HOVER` 1.3 tiles up, the client's 0.35 in character space, research 12, §25.13.5 — an enemy flyer from the road whatever tile it crosses (GitHub #277) —, shadow sprite on the ground), elite gold outline glow, tier chip, HP bar (green ally / red enemy), SP bar (skill ready glow; while an ammo skill runs it is the magazine instead — a yellow cell per round, emptying from the right, `b.snap ammo`, and the skill draws no standing aura, UnitInfo `ammoSkill`), 斩业星熊's 我执 pool as a red bar over her drained HP bar (`b.snap neg`), 伺夜's 狼群 count as a row of diamonds under the bars, the lit ones the 狼影 left (`b.snap wolves`; 0.2.2, GitHub PR #303 / #378 / #383), status icons, the element gauge row under the bars — icon + white bar of the remaining 元素值, element-coloured refill during a 爆发冷却 (§18.3, §20.8); enemies drawn × their official prefab factor (enemies.json `modelScale`, §20.4); an enemy's mode — the `form` of a sim fx (`shared/protocol.js fxForm`), or UnitInfo `form` for a view built later through `render/app/info.js renderInfo` — switches clip sets (`render/units.js FORMS`: 掠海漂移体 crawl, 暴鸰 bombed, 转译基底's forms, the 逐火 embers, the leaders' 重生, 守墓石像, the 孤岛风云 prisoners' warning and 解放; closing clips timed from the fx `dur`), a one-off cast (`PROJ[kind].once`) plays once, and a local-only model's web alias is tinted (`ALIAS_TINT`: 灼热 / 炽焰源石虫, §21.14); damage numbers (phys orange-white, arts purple, true white, heal green); projectiles drawn per kind, hit sparks and melee slashes, skill activation bursts and auras (§17.3); death fade for enemies, summons and devices — a knocked-out operator stays on its tile in its held Die pose under a redeploy ring (§18.3); leak flash at the objective. Fallback when Spine missing/failed: avatar in a rarity-coloured diamond with bob/lunge tweens — a failed or timed-out model is loaded again (bounded), and a view re-resolves its model and avatar when the asset manifest arrives late or the tab is shown again (§21.27). 60 fps target with ≤ 120 units (a crowd draws its Spine units through the cached atlas, `render/impostor.js`, each refreshed every k-th frame: the refresh turns follow this frame's update order — `ctx.impostorSlot()`, a counter reset at the start of every frame — so a frame refreshes ⌊n/k⌋ or ⌈n/k⌉ of n units instead of whatever random per-unit phases gave, and a unit not refreshed for 2k frames is refreshed regardless; GitHub PR #334 by @Cloudnyco, issue #327 step 1 — its step 2, a time budget by priority, is not done; a model whose pose cannot change — `SpineActor.poseHeld()`: a knocked-out operator in the held end of its Die clip, a frozen model — is neither re-posed nor redrawn, only its clock runs, until a new clip, a revive, a wind-up, a form's closing clip, a clipping switch or a zoom past the impostor's rescale threshold; an impostor's slot is sized from the unit's setup pose and every clip it can play — measured once per skeleton, a few frames after the model loads (`render/spine.js clipBounds`, sampled within a 2.5 ms frame budget; until then the unit is drawn directly) —, a clip too large for that box (`render/units.js impostorBox`: mostly a deploy drop from above) is drawn directly while it plays, and the atlas draws every slot clipped to its own rectangle (a scissor rect), so no pose is cut and nothing is left in another unit's slot (GitHub #542, §31.6); the redeploy rings draw one shared rasterised label per number, `render/textures.js downLabel`, the same pixels as a Text of their own). Picking (which unit a press / hover / dropped item is on) and the drag target follow one rule, `render/pick.js` — the tile under the pointer (§18.1); the Spine store never hands out a skeleton whose unload is in flight (§17.1).
 
 ---
 

docs/history/0.2.6.md

@@ -104,3 +104,54 @@ keeps finished players for display, so its total length cannot establish that a
 counts order entries absent from `draft.picks`, alongside the existing turn and quota checks. The server's
 `skipBand` already rejects the final player with `BAD_TARGET / nobody to pass to`; its rule remains unchanged.
 Regression covers normal two-, three- and four-human browser flows, the final turn, and exhausted quota.
+
+### 31.6 Impostor bounds and slot clearing (#542)
+
+`render/spine.js clipBounds / stepClipBounds`, `render/units.js impostorBox / _impBox / _impBypass`, `render/impostor.js`.
+
+- **Seen** (GitHub #542 by @ImPQlc; quality 高, usually from round 7 on): 野鬃's flag cut, offset and leaving stray pixels
+  while she idles; 浊心斯卡蒂's head cut in her S3 flight (Skill_3_Begin); 隐现's pistol muzzle cut, offset and leaving
+  stray pixels during her skill.
+- **Cause** (reproduced in headless Chrome: the dev demo's stress crowd, 120 units at impostor interval 4, the three held
+  in their widest poses): a unit's impostor slot was sized once from the pose it showed when it first became an impostor,
+  plus a margin (`_impBox`: the pose's bounds + 30 % / 22 %). A later pose past that box was drawn past the slot's edge:
+  cut in the unit's own sprite and painted into whatever lay beside the slot on the atlas page. A page is cleared on its
+  first flush only and each eraser covers its own slot, so a spill into free space stayed, and a spill into another unit's
+  slot showed on that unit until it was redrawn in a frame without the spill. 浊心斯卡蒂's flight reaches y −704 (skeleton
+  units) against a box top near −516 (54–57 px past her slot in 5 of 5 runs); 野鬃's idle flag reaches x −434, 103 units
+  past a box sized from her setup pose (0–47 px past her slot over 5 runs: it depended on that first pose); after one clean
+  redraw of every impostor the atlas pages held 0–1,405 pixels outside every live slot. 隐现's own poses fit her box (the
+  silencer reaches x 197, her box 225): her muzzle sits at her slot's edge, where a neighbour's spill lands. Of the
+  roster's 681 skeletons, 598 play a clip that leaves a box sized that way from their idle's first frame. No clipping
+  attachment is involved (`spine.js _eyeMaskFallback`, #177, unchanged).
+- **Now**: (1) every clip a unit can play (its manifest roles with every skill's set and the Run cycle, its `FORMS` clip
+  sets and change clips) is measured once per skeleton data on a scratch skeleton: 60 poses a second, at most 49 per clip;
+  a region by its attachment rectangle, a mesh by its vertices; slots drawn at alpha 0 skipped. It is queued when the model
+  loads and sampled within 2.5 ms per frame (`stepClipBounds`, called by `render/app.js`), ≈ 9 ms per skeleton on the
+  roster (53 ms at most), shared by every unit of that skeleton; a unit is drawn directly until its box is ready. (2) The
+  box is the setup pose ∪ the idle clip (never smaller than the setup pose), then each other clip in the order of the area
+  it adds while the box stays within 4 × that core (a looping or held clip) or 2 × (a one-off clip: the deploy clip, a
+  skill's, stun's or move's begin and end, a form's change), padded by 3 % + 8 units. A clip that does not fit (`over`: 319
+  of the roster's 681 deploy clips — the drop from above, up to 1,700 units tall — and the looping clips of 6 skeletons with
+  screen-wide effects) is drawn directly while it plays; the unit keeps its slot (`_impBypass`). The box is computed once
+  per unit: no bounds work per frame. (3) The atlas draws each slot's skeleton in a container masked by the slot rectangle,
+  which PIXI draws as a scissor rect (no stencil, no render-pass break): nothing paints outside a slot, and the slot's
+  eraser clears all that an earlier pose can have left in it.
+- **Cost**: slot sizes grow with the boxes. The 120-unit stress crowd at 1600 × 900 (DPR 1) uses 8.7 M px of slots instead
+  of 4.4 M (2.7 instead of 1.2 atlas pages, still no private render target). On the roster the boxes add up to 1.86 × the
+  old area (the median skeleton 1.39 ×; without the setup-pose floor it would be 1.23 ×). The atlas keeps its ≤ 3 + 2 pages;
+  a unit that finds no slot keeps a private render target, as before. CPU: one batch flush per redrawn slot.
+  `tools/perfbench.mjs` (844 × 390, DPR 2, quality medium / low, where those battles draw through the atlas; 12 runs of
+  6 s): total busy JS +0.8 %, the impostor-redraw stage +14 % (+0.1–0.25 ms per frame at a 4 × CPU throttle), 60 fps in
+  every run before and after.
+- [ASSUMED]: the growth limits (4 × / 2 ×), the 3 % + 8 padding, the sampling rate and the 2.5 ms budget. A pose between two
+  samples can still pass the padded box for a frame (33 of the 681 skeletons by a denser 60 Hz check, all in long clips
+  sampled sparser than that); the scissor cuts it and leaves nothing behind.
+- Tests: `test/render/impostor-bounds.test.js` (synthetic Spine 3.8 skeletons: setup and clip bounds, an attachment shown
+  for 0.05 s, an alpha-0 slot, the budgeted queue; `impostorBox` / `playedClips`; every atlas slot's clip box and eraser;
+  UnitView: drawn directly until measured, the over-clip bypass keeping its slot, the legacy fallback, a pen figure),
+  `test/render/impostor-bounds-models.test.js` (the three operators through the real runtime: every pose of every clip
+  they play, at 30 Hz, inside their box; the old box cut 野鬃 by 103 units and 浊心斯卡蒂 by 188; skips without the
+  assets), `test/render/impostor-bounds.browser.test.js` (`RENDER_E2E=1`: the held stress crowd — inside their slots, no
+  atlas pixel outside a live slot; the scissor on a bare page; 野鬃's deploy drawn directly), `test/render/boardart.test.js`
+  (the allocator's test doubles). Dev: `render-demo.html?scene=stress&ops=<chessId>,…`. Golden: unchanged.