fix: crash when recording right after loading mp_coop_wall_5

src/Modules/MaterialSystem.cpp

@@ -45,6 +45,7 @@ class MemTexRegen : public ITextureRegenerator {
 };
 
 REDECL(MaterialSystem::UncacheUnusedMaterials);
+REDECL(MaterialSystem::CacheUsedMaterials);
 REDECL(MaterialSystem::CreateMaterial);
 
 DETOUR(MaterialSystem::UncacheUnusedMaterials, bool bRecomputeStateSnapshots) {
@@ -56,6 +57,22 @@ DETOUR(MaterialSystem::UncacheUnusedMaterials, bool bRecomputeStateSnapshots) {
 	return result;
 }
 
+// CacheUsedMaterials ends in CTextureManager::ForceAllTexturesIntoHardware,
+// which queues a draw of every listed texture without referencing it. When an
+// entity released its last reference to a texture earlier in the frame (the
+// client runs this after every full update, which recreates all entities), the
+// render thread frees that texture before it gets to the preload draw, which
+// then crashes. `record` right after a load hits this on maps with a playing
+// movie screen (mp_coop_wall_5). Turning threading off for the call runs the
+// pending queue first, like the engine does around screenshots.
+DETOUR(MaterialSystem::CacheUsedMaterials) {
+	auto AllowThreading = materialSystem->materials->Original<_AllowThreading>(Offsets::AllowThreading);
+	bool allowed = AllowThreading(thisptr, false, 0);
+	auto result = MaterialSystem::CacheUsedMaterials(thisptr);
+	AllowThreading(thisptr, allowed, 0);
+	return result;
+}
+
 DETOUR_T(IMaterial *, MaterialSystem::CreateMaterial, const char *pMaterialName, void *pVMTKeyValues) {
 	if (sar.game->Is(SourceGame_Portal2 | SourceGame_Portal2_2011 | SourceGame_PortalReloaded | SourceGame_PortalStoriesMel)) {
 		// Patched by Valve, no need for us to do it again
@@ -88,6 +105,9 @@ bool MaterialSystem::Init() {
 	if (this->materials) {
 		this->materials->Hook(MaterialSystem::UncacheUnusedMaterials_Hook, MaterialSystem::UncacheUnusedMaterials, Offsets::UncacheUnusedMaterials);
 		this->materials->Hook(MaterialSystem::CreateMaterial_Hook, MaterialSystem::CreateMaterial, Offsets::CreateMaterial);
+		if (Offsets::CacheUsedMaterials) {
+			this->materials->Hook(MaterialSystem::CacheUsedMaterials_Hook, MaterialSystem::CacheUsedMaterials, Offsets::CacheUsedMaterials);
+		}
 
 		this->RemoveMaterial = this->materials->Original<_RemoveMaterial>(Offsets::RemoveMaterial);
 

src/Modules/MaterialSystem.hpp

@@ -26,8 +26,11 @@ class MaterialSystem : public Module {
 	using _KeyValues_SetString = void(__rescall*)(void* thisptr, const char *key, const char *val);
 	_KeyValues_SetString KeyValues_SetString = nullptr;
 
+	using _AllowThreading = bool(__rescall *)(void *thisptr, bool bAllow, int nServiceThread);
+
 public:
 	DECL_DETOUR(UncacheUnusedMaterials, bool bRecomputeStateSnapshots);
+	DECL_DETOUR(CacheUsedMaterials);
 	DECL_DETOUR_T(IMaterial *, CreateMaterial, const char *pMaterialName, void *pVMTKeyValues);
 
 	bool Init() override;

src/Offsets/Portal 2 10090.hpp

@@ -344,6 +344,8 @@ OFFSET_DEFAULT(snd_p, 98, 116)
 OFFSET_DEFAULT(snd_vol, 108, 122)
 OFFSET_DEFAULT(StartTouch, 102, 103)
 OFFSET_DEFAULT(UncacheUnusedMaterials, 77, 77)
+OFFSET_DEFAULT(CacheUsedMaterials, 78, 78) // client -> "LevelInitPreEntity - CacheUsedMaterials - Start" xref -> CPrecacheRegister::LevelInitPreEntity() -> following vtable call -> CMaterialSystem::CacheUsedMaterials
+OFFSET_DEFAULT(AllowThreading, 135, 135) // materialsystem -> "Queued Material System: ENABLED!\n" xref -> CMaterialSystem::AllowThreading -> vtable index
 OFFSET_DEFAULT(CreateMaterial, 81, 81)
 OFFSET_DEFAULT(FindMaterial, 82, 82)
 OFFSET_DEFAULT(CreateProceduralTexture, 91, 91)

src/Offsets/Portal 2 8151.hpp

@@ -1,6 +1,9 @@
 #include "Offsets/Portal 2 10090.hpp"
 // Portal Stories: Mel, Reloaded
 
+OFFSET_DEFAULT(CacheUsedMaterials, 0, 0) // texture preload fix only verified on Portal 2 10090
+OFFSET_DEFAULT(AllowThreading, 0, 0)
+
 OFFSET_LINUX(tickcount, 74)
 OFFSET_LINUX(interval_per_tick, 82)
 OFFSET_LINUX(demoplayer, 92)