Fix inconsistency between GapGen and SpySat causing desyncs

CREDITS.md

@@ -288,6 +288,7 @@ This page lists all the individual contributions to the project by their author.
   - Customizable paradrop missions
   - Guard range customizations
   - Wall overlay unit sell exploit fix
+  - GapGen + SpySat desync fix
 - **Morton (MortonPL)**:
   - `XDrawOffset` for animations
   - Shield passthrough & absorption

docs/Fixed-or-Improved-Logics.md

@@ -300,6 +300,7 @@ This page describes all ingame logics that are fixed or improved in Phobos witho
 - Fixed the bug in AI scripts 56 and 57 that forced the launch of superweapons with index numbers 3 and 4.
 - Buildings with `NeedsEngineer=true` are now considered to have threat value of 0 under ownership of `MultiplayPassive=true` houses regardless of their `ThreatPosed` value.
 - Vehicles overlapping `Wall=true` OverlayTypes no longer display sell cursor and cannot be sold.
+- Fixed a desync due to an inconsistent shroud state caused by `GapGenerator` and `SpySat` interaction.
 
 ## Fixes / interactions with other extensions
 

docs/Whats-New.md

@@ -651,6 +651,7 @@ Fixes / interactions with other extensions:
 
 Vanilla fixes:
 - Vehicles overlapping `Wall=true` OverlayTypes no longer display sell cursor and cannot be sold (by CnCRAZER & Starkku)
+- Fixed a desync due to an inconsistent shroud state caused by `GapGenerator` and `SpySat` interaction (by Starkku)
 
 Phobos fixes:
 - Fixed vehicles disguised as trees incorrectly displaying veterancy insignia when they shouldn't (by Starkku)

src/Misc/Hooks.BugFixes.cpp

@@ -3077,3 +3077,92 @@ DEFINE_HOOK(0x6EA870, TeamClass_LiberateMember_Start, 0x6)
 	pMember->RecruitableB = true;
 	return 0;
 }
+
+#pragma region ShroudFix
+
+// These map cells are what SpySat skips revealing in MP normally.
+static bool inline ShroudFix_IsCellInvalid(CellStruct* pMapCell)
+{
+	int x = pMapCell->X;
+	int y = pMapCell->Y;
+	auto const& rect = MapClass::Instance.MapRect;
+
+	if (x == 7 && y == rect.Width + 5)
+		return true;
+
+	if (x == 13 && y == rect.Width + 11)
+		return true;
+
+	if (x == rect.Height + 13 && y == rect.Width + rect.Height -15 )
+		return true;
+
+	return false;
+}
+
+DEFINE_HOOK(0x6FB5E5, TechnoClass_DeleteGap_CellCheck, 0x5)
+{
+	enum { SkipCell = 0x6FB6F3 };
+
+	GET(CellStruct*, pMapCell, EDX);
+
+	if (ShroudFix_IsCellInvalid(pMapCell))
+		return SkipCell;
+
+	return 0;
+}
+
+DEFINE_HOOK(0x6FB2FB, TechnoClass_CreateGap_CellCheck, 0x5)
+{
+	enum { SkipCell = 0x6FB416 };
+
+	GET(CellStruct*, pMapCell, EDX);
+
+	if (ShroudFix_IsCellInvalid(pMapCell))
+		return SkipCell;
+
+	return 0;
+}
+
+// Replace the entire cell iterator loop for perf reasons.
+DEFINE_HOOK(0x577AFF, MapClass_ResetShroud_CellCheck, 0x6)
+{
+	enum { SkipGameCode = 0x577B75 };
+
+	auto& map = MapClass::Instance;
+	map.CellIteratorReset();
+
+	for (auto pCell = map.CellIteratorNext(); pCell; pCell = map.CellIteratorNext())
+	{
+		if (ShroudFix_IsCellInvalid(&pCell->MapCoords))
+			continue;
+
+		pCell->Flags &= ~(CellFlags::CenterRevealed | CellFlags::EdgeRevealed);
+		pCell->AltFlags &= ~(AltCellFlags::Mapped | AltCellFlags::NoFog);
+		pCell->ShroudCounter = 1;
+		pCell->GapsCoveringThisCell = 0;
+	}
+
+	return SkipGameCode;
+}
+
+// Replace the entire cell iterator loop for perf reasons.
+DEFINE_HOOK(0x577BF1, MapClass_ResetShroudForTMission_CellCheck, 0x6)
+{
+	enum { SkipGameCode = 0x577C57 };
+
+	auto& map = MapClass::Instance;
+	map.CellIteratorReset();
+
+	for (auto pCell = map.CellIteratorNext(); pCell; pCell = map.CellIteratorNext())
+	{
+		if (ShroudFix_IsCellInvalid(&pCell->MapCoords))
+			continue;
+
+		pCell->Flags &= ~(CellFlags::CenterRevealed | CellFlags::EdgeRevealed);
+		pCell->AltFlags &= ~(AltCellFlags::Mapped | AltCellFlags::NoFog);
+	}
+
+	return SkipGameCode;
+}
+
+#pragma endregion

src/Phobos.cpp

@@ -271,6 +271,18 @@ void Phobos::ApplyOptimizations()
 
 	if (!SessionClass::IsMultiplayer())
 	{
+		// Disable TechnoClass_DeleteGap_CellCheck
+		Patch::Apply_RAW(0x6FB5E5, { 0xB9, 0xE8, 0xF7, 0x87, 0x00 });
+
+		// Disable TechnoClass_CreateGap_CellCheck
+		Patch::Apply_RAW(0x6FB2FB, { 0xB9, 0xE8, 0xF7, 0x87, 0x00 });
+
+		// Disable MapClass_ResetShroud_CellCheck
+		Patch::Apply_RAW(0x577AFF, { 0x8B, 0x86, 0xF4, 0x00, 0x00, 0x00 });
+
+		// Disable MapClass_ResetShroudForTMission_CellCheck
+		Patch::Apply_RAW(0x577BF1, { 0x8B, 0x86, 0xF4, 0x00, 0x00, 0x00 });
+
 		// Disable Random2Class_Random_SyncLog
 		Patch::Apply_RAW(0x65C7D0, { 0xC3, 0x90, 0x90, 0x90, 0x90 });