Jayden/sharpemu
1
0
Fork 0
mirror of https://github.com/par274/sharpemu.git synced 2026-07-22 19:06:15 +08:00
Code Issues Packages Projects Releases Wiki Activity

Fix pak size-collision that crashed Quake right after the intro demo (#187)

Browse Source 
* [Tests] Add SharpEmu.Libs.Tests project

Introduce an xunit project for the HLE libs with a minimal ICpuMemory fake,
so library-level exports and helpers can be exercised without a live guest.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* [Ampr] Disambiguate pak size-collisions by read locality

PakDirectoryTracker resolves a sequential AMPR read (offset -1) back to an
absolute pak offset by matching the requested byte count against the PACK
directory. When several files share that byte count it took the first
unconsumed match in directory order, which mis-resolves out-of-order reads:
progs/h_ogre.mdl and bots/navigation/death32c.nav are both 0x3A34 bytes, and
death32c.nav sits earlier in the directory and is never read during Quake's
intro demo, so requesting h_ogre.mdl returned the nav file's bytes. The engine
then parsed "NAV2" as a brush model, failed the version check and aborted.

Pick the unconsumed same-size entry nearest the running read cursor instead.
id archives cluster related assets and the guest streams them with locality,
so this lands on the intended file; contiguous same-size runs (the
gfx/weapons/ww_*.lmp icons) still resolve in packed order.

Verified against a Quake dump: the abort is gone, h_ogre.mdl reads correctly,
and the intro demo reaches its main loop and renders instead of dying at the
error dialog.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
José Luis Caravaca Carretero
2026-07-15 00:49:41 +02:00
committed by GitHub
parent df53ff59d9
commit e604fb606d
2 changed files with 139 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/SharpEmu.Libs/Ampr/PakDirectoryTracker.cs
+31 -10
View File
@@ -54,20 +54,41 @@ internal static class PakDirectoryTracker
if (state.Directory is { } entries)
{
// Several unrelated archived files can share a byte count (e.g. a head model and a bot
// navigation file both 0x3A34 bytes). Directory order alone then picks whichever comes
// first, which is wrong when the game reads them out of order. id archives cluster
// related assets, and the guest streams them with locality, so disambiguate collisions
// by choosing the unconsumed match nearest the running read cursor.
DirectoryEntry? best = null;
var bestDistance = ulong.MaxValue;
foreach (var entry in entries)
{
if (!entry.Consumed && entry.FileLen == requestedSize)
if (entry.Consumed || entry.FileLen != requestedSize)
{
entry.Consumed = true;
if (_trace)
{
Console.Error.WriteLine(
$"[LOADER][TRACE] pak.directory_match: id=0x{fileId:X8} name='{entry.Name}' " +
$"filepos=0x{entry.FilePos:X8} filelen=0x{entry.FileLen:X8}");
}
return entry.FilePos;
continue;
}
var distance = entry.FilePos >= state.NextOffset
? entry.FilePos - state.NextOffset
: state.NextOffset - entry.FilePos;
if (distance < bestDistance)
{
bestDistance = distance;
best = entry;
}
}
if (best is not null)
{
best.Consumed = true;
if (_trace)
{
Console.Error.WriteLine(
$"[LOADER][TRACE] pak.directory_match: id=0x{fileId:X8} name='{best.Name}' " +
$"filepos=0x{best.FilePos:X8} filelen=0x{best.FileLen:X8}");
}
return best.FilePos;
}
}