Verify level 1's tfrag lighting against the game

Savestate slot 2 is the second planet, so the comparison runs on a level with
a different geometry extent, light bank and runtime-set population:

  level1: 401/401 headers, 401/401 pointers, bank byte-identical
  vertices compared: 26470 (105880 colour bytes)  -- equal: 100.00%

The live emulator agrees with the savestate byte for byte. Level 1 is a
different planet, so the two fixes in the previous commit are not level-0
coincidences: the normal's z sign and the unlit-record base colour both hold
across 268,280 colour bytes on two levels.
This commit is contained in:
2026-10-11 20:50:36 +02:00
parent 69a8398f6e
commit bbdb51e2f9
+25 -6
View File
@@ -37,10 +37,10 @@ The comparison:
few mismatching vertices' *terms* (`gc_engine::tfrag_light::
light_vertex_terms`) printed so a mismatch can be attributed.
## Result: level 0 (Veldin), verified 2026-10-11
## Result: levels 0 and 1, verified 2026-10-11
Inputs: the live emulator over PINE, and two PCSX2 savestates from the same
level. All three agree byte for byte.
Level 0 (Veldin), three inputs -- the live emulator over PINE and two PCSX2
savestates from that level, all agreeing byte for byte:
```text
level0: tfrags block at 0x848000, table at 0x848040, 833 tfrags
@@ -54,6 +54,25 @@ vertices compared: 40600 (162400 colour bytes)
single-set: 37470 vertices, 37470 fully equal
```
Level 1, from savestate slot 2 and cross-checked against the live emulator:
```text
level1: tfrags block at 0x84c000, table at 0x84c040, 401 tfrags
headers matching the disc on invariant bytes: 401/401
data pointers relocated as table + disc offset: 401/401
light bank in RAM at 0x50f4a0, byte-identical to the disc's
vertices compared: 26470 (105880 colour bytes)
equal: 105880 (100.00%)
runtime-set: 129 vertices, 129 fully equal
single-set: 26341 vertices, 26341 fully equal
```
Level 1 matters more than one more tally: it is a different planet with a
different geometry extent, a different light bank and a different
runtime-set population, and it agrees on every byte. The two fixes below are
therefore not level-0 coincidences.
What this establishes:
- **The tfrag locator and the pointer model are right.** 833 of 833 headers
@@ -94,9 +113,9 @@ invisible.
- **Point lights.** The runtime-set cluster is set 15 and above; those slots
are filled by gameplay, so they cannot be verified from a level-load image.
Comparing them needs a frame with point lights in it.
- **Blended sets.** Level 0's vertices are all single-set (`select & 0xff00 ==
0`), so the blend path -- the only path `rsqrt` touches -- is untested
against the game.
- **Blended sets.** Both levels' vertices are all single-set (`select &
0xff00 == 0`), so the blend path -- the only path `rsqrt` touches -- is
untested against the game.
- **Distil, then test.** A comparison is not a regression. When a fact from
here becomes load-bearing, distil it into a numbers-only fixture under
`tools/trace/tests/` and test against that; no test may read a savestate, a