From 1d2f0014f165497a66f0eb73a9d923ed5d726bbc Mon Sep 17 00:00:00 2001
From: Silent <zdanio95@gmail.com>
Date: Tue, 27 Feb 2024 22:27:51 +0100
Subject: [PATCH] Fix the random chance of cars not turning lights on when it's
 foggy or rainy

On PC, they would always eventually turn the lights on due to a different
range of randomness.

Fixes #2
---
 SilentPatch/Common.cpp          | 19 +++++++++++++++++++
 SilentPatchSA/SilentPatchSA.cpp | 18 ++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/SilentPatch/Common.cpp b/SilentPatch/Common.cpp
index 205ef66..1fa0d61 100644
--- a/SilentPatch/Common.cpp
+++ b/SilentPatch/Common.cpp
@@ -235,6 +235,25 @@ namespace Common {
 				InjectHook( resetComps.get<void>( -14 ), ResetCompsForNoExtras, HookType::Call );
 				Nop( resetComps.get<void>( -9 ), 9 );
 			}
+
+
+			// Rescale light switching randomness in CAutomobile::PreRender/CBike::PreRender for PC the randomness range
+			// The original randomness was 50000 out of 65535, which is impossible to hit with PC's 32767 range
+			{
+				// GTA III expects 2 matches, VC expects 4 due to the addition of CBike::PreRender
+#if _GTA_III
+				constexpr uint32_t expected = 2;
+#else
+				constexpr uint32_t expected = 4;
+#endif
+				auto matches = pattern("D8 0D ? ? ? ? D8 1D ? ? ? ? DF E0 80 E4 05 80 FC 01").count(expected);
+
+				matches.for_each_result([](pattern_match match)
+				{
+					static const float LightStatusRandomnessThreshold = 1.0f / 25000.0f;
+					Patch<const void*>(match.get<void>(2), &LightStatusRandomnessThreshold);
+				});
+			}
 		}
 
 		void III_VC_SetDelayedPatchesFunc( void(*func)() )
diff --git a/SilentPatchSA/SilentPatchSA.cpp b/SilentPatchSA/SilentPatchSA.cpp
index 86d5f67..8844092 100644
--- a/SilentPatchSA/SilentPatchSA.cpp
+++ b/SilentPatchSA/SilentPatchSA.cpp
@@ -5198,6 +5198,14 @@ void Patch_SA_10(HINSTANCE hInstance)
 		InjectHook(0x6CD545, CheckIfInPlayerGroupAndOnAMission, HookType::Jump);
 	}
 
+
+	// Rescale light switching randomness in CVehicle::GetVehicleLightsStatus for PC the randomness range
+	// The original randomness was 50000 out of 65535, which is impossible to hit with PC's 32767 range
+	{
+		static const float LightStatusRandomnessThreshold = 1.0f / 25000.0f;
+		Patch<const void*>(0x6D5612 + 2, &LightStatusRandomnessThreshold);
+	}
+
 #if FULL_PRECISION_D3D
 	// Test - full precision D3D device
 	Patch<uint8_t>( 0x7F672B+1, *(uint8_t*)(0x7F672B+1) | D3DCREATE_FPU_PRESERVE );
@@ -6882,6 +6890,16 @@ void Patch_SA_NewBinaries_Common(HINSTANCE hInstance)
 		SkipTargetting = skipTargetting;
 		InjectHook(targettingCheck.get<void>(), CheckIfInPlayerGroupAndOnAMission_Steam, HookType::Jump);
 	}
+
+
+	// Rescale light switching randomness in CVehicle::GetVehicleLightsStatus for PC the randomness range
+	// The original randomness was 50000 out of 65535, which is impossible to hit with PC's 32767 range
+	{
+		auto getVehicleLightsStatus = get_pattern("DC 35 ? ? ? ? D9 05 ? ? ? ? D8 D9", 2);
+
+		static const double LightStatusRandomnessThreshold = 25000.0;
+		Patch<const void*>(getVehicleLightsStatus, &LightStatusRandomnessThreshold);
+	}
 }