D341: intro gun-barrel blood drip drew static garbage

Two fast3d defects. (1) The 1-cycle blood texture rectangle sampled a
stale tile-1 CI8 declaration: the title leaves G_TL_LOD set and the D236
detail-base rule redirected texunit 0 to tile 1. LOD tile selection is
2-cycle-only on the RDP, so texrects outside 2-cycle now sample their own
tile. (2) The drip image is regenerated in place in the dyn pool (reached
via the KSEG0 mirror); the address-only cache key froze it on its first
image. Dyn-pool textures now key on a content hash. Headless-verified,
golden 3/3. A/B: GE_DYNTEXHASH_OFF.

docs/dev/findings.md

@@ -626,6 +626,7 @@ covers D24–D69; the log continues in §H (D32 procedure, D70–D121).
 | D337 | **Aim modes folded (user decision): N64 (default) = the N64 aim model with the mouse fed through the game's integrator at PD's damp (D332 made default); CENTRED (PC) opt-in; Q/L and Toggle-aim now route mouse aim like RMB; pad/keyboard aim no longer swallowed by the mouse integration.** — full `## D337` entry at file tail | FIXED (2026-09-26 bookkeeping: shipped; user reports it feels good in v0.4.0 play). Earlier: IMPLEMENTED (port/src/input.c + optionsoverlay.c); headless-measured with new scripted-mouse harness; golden 3/3; Win + Linux builds. Open: N64-range calibration decision. |
 | D338 | **`Input.AimRange` (F10 "Aim range"): PC (default, GEPD/mouse-injector full-screen crosshair) or N64 (original stick limits: 65% of half-width, camera turn from ~49%).** — full `## D338` entry at file tail | FIXED (2026-09-26 bookkeeping: shipped; user reports it feels good in v0.4.0 play). Earlier: IMPLEMENTED + measured (PC 98%/72%, N64 65%/49%); golden 3/3; Win + Linux builds. |
 | D339 | **#92 (low-end ~30 fps, Celeron N3060 / HD 400) — measured CPU budget: game thread ~0.2–0.35 ms/frame, render-thread display-list pass 0.4–1.8 ms/frame on this box; CPU very likely not the bottleneck. New `GE_PERFSTAT=1` probe (render phases, tris/batches, game-thread busy, GPU timer query).** — full `## D339` entry at file tail | OPEN (2026-09-26, user: review toward the end of v0.4.0; needs a test machine with similar HD 400-class hardware). Earlier: INVESTIGATING — probe landed; target-hardware numbers needed before any fix. |
+| D341 | **Intro gun-barrel blood drip draws as static blocks/lines instead of dripping (user, v0.4.0, 2026-09-26; death blood fine).** — full `## D341` entry at file tail | FIXED (M-201): two fast3d defects — the 1-cycle blood texrect sampled a stale tile-1 declaration via the D236 LOD rule, and the in-place-regenerated dyn-pool texture hit a stale address-keyed cache entry. |
 
 Phase 2 replaced the Phase-1 demo loop with the real `mainproc()` on real OS
 threads, compiled GE's real `src/sched.c`, and brought in PD's fast3d software
@@ -13497,3 +13498,17 @@ Implemented as `Input.PdMouseAim` (**default off**, because it changes aim feel)
 
 **Next (needs HD 400-class hardware, not reporter logs):** run `GE_PERFSTAT=1` on a comparable machine at defaults vs MSAA 1 / aniso 1 / bilinear; if GPU-bound, consider a first-run low-end preset (the Steam Deck preset, `da31edaa`, is the precedent) keyed on the GL renderer. CPU-side headroom if ever needed: batches per frame (100–411) is the obvious lever (state-change batching in `gfx_flush`).
 
+## D341 — Intro gun-barrel blood drip draws as static blocks/lines instead of dripping (M-201, 2026-09-26)
+
+**Report:** the 2D red blood "drip" at the end of the gun-barrel intro glitches and doesn't draw right; the death blood looks normal.
+
+**Measured:** `die_blood_image_routine` builds a correct 96x80 I4 drip image each step (dumped and rendered: a growing top band with drips); `gunbarrelBloodOverlayDL` draws it as a full-screen 1-cycle texture rectangle at the title's 440x330 VI (dsdx 223, dtdy 248, tile 0 = I4 96x80, `GE_D116` confirmed). The screen showed a constant pattern of red blocks and horizontal lines that never changed.
+
+**Cause 1 (the wrong image):** texture-unit 0 imported from **tile 1** (`unit=0 tile=1 cyc=1CYCLE lod=1`): the title leaves `G_TL_LOD` set from earlier draws, and `gfx_lod_tile_offset`'s D236 detail-base rule (tile 1 in different TMEM with a different format → sample tile 1) redirected the rectangle to a stale CI8 tile-1 declaration sharing TMEM 0 — 128 bytes of the blood buffer decoded as CI8 and stretched. On the RDP, LOD tile selection only exists in 2-cycle mode; a 1-cycle texture rectangle samples exactly its command's tile. Fix: `gfx_lod_tile_offset` returns `i` while a texture rectangle is drawing outside 2-cycle mode (`s_in_texrect`, set around `gfx_draw_rectangle` in the texrect + wide-texrect paths). 3D triangle paths (D107/D236) are unchanged.
+
+**Cause 2 (frozen animation):** the image is regenerated in place in the per-frame dynamic pool, at the same address every step, and reached via `OS_K0_TO_PHYSICAL` → the KSEG0 mirror (`0x800a8f20`). The GL texture cache keys non-CI textures on address only, so after the first import every later step was a stale hit. Fix: textures in the dyn pool (`[g_VtxBuffers[0], g_VtxBuffers[2])`, with the 0x80000000 mirror normalised to V1) get an FNV-1a content hash in the key. A/B with `GE_DYNTEXHASH_OFF=1`: blood coverage stays at 1% (frozen); with it, the drip grows.
+
+**Verified:** headless boot capture — the blood now runs down from the top over the gun barrel as on N64 (`scratch/blood_after.png`). Golden gate 3/3. User visual check owed.
+
+**Status: FIXED (M-201, headless-verified 2026-09-26).**
+