From d216c5776b08f1892f2f251e352743788e01ff26 Mon Sep 17 00:00:00 2001
From: Uladzislau Nikalayevich <thenormalnij@gmail.com>
Date: Tue, 10 Dec 2024 00:22:55 +0300
Subject: [PATCH] Allow dynamic models to be created as buildings

---
 Client/game_sa/CBuildingsPoolSA.cpp           | 12 ++++++++-
 Client/game_sa/CModelInfoSA.h                 |  2 +-
 .../logic/CClientBuildingManager.cpp          | 27 +------------------
 Client/sdk/game/CModelInfo.h                  |  3 +++
 4 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/Client/game_sa/CBuildingsPoolSA.cpp b/Client/game_sa/CBuildingsPoolSA.cpp
index 50ae14bb3c..ef30e81283 100644
--- a/Client/game_sa/CBuildingsPoolSA.cpp
+++ b/Client/game_sa/CBuildingsPoolSA.cpp
@@ -53,6 +53,13 @@ CBuilding* CBuildingsPoolSA::AddBuilding(CClientBuilding* pClientBuilding, uint1
     if (!HasFreeBuildingSlot())
         return nullptr;
 
+    auto modelInfo = pGame->GetModelInfo(modelId);
+
+    // Change the properties group to force dynamic models to be created as buildings instead of dummies
+    auto prevGroup = modelInfo->GetObjectPropertiesGroup();
+    if (prevGroup != MODEL_PROPERTIES_GROUP_STATIC)
+        modelInfo->SetObjectPropertiesGroup(MODEL_PROPERTIES_GROUP_STATIC);
+
     // Load building
     SFileObjectInstance instance;
     instance.modelID = modelId;
@@ -70,9 +77,12 @@ CBuilding* CBuildingsPoolSA::AddBuilding(CClientBuilding* pClientBuilding, uint1
     pBuilding->m_pLod = nullptr;
     pBuilding->m_iplIndex = 0;
 
+    // Resore changes properties group
+    if (prevGroup != MODEL_PROPERTIES_GROUP_STATIC)
+        modelInfo->SetObjectPropertiesGroup(prevGroup);
+
     // Always stream model collosion
     // TODO We can setup collison bounding box and use GTA streamer for it
-    auto modelInfo = pGame->GetModelInfo(modelId);
     modelInfo->AddColRef();
 
     // Add building in world
diff --git a/Client/game_sa/CModelInfoSA.h b/Client/game_sa/CModelInfoSA.h
index b261bcc04a..889608404a 100644
--- a/Client/game_sa/CModelInfoSA.h
+++ b/Client/game_sa/CModelInfoSA.h
@@ -466,7 +466,7 @@ class CModelInfoSA : public CModelInfo
     // Vehicle towing functions
     bool IsTowableBy(CModelInfo* towingModel) override;
 
-    bool IsDynamic() { return m_pInterface ? m_pInterface->usDynamicIndex != 0xffff : false; };
+    bool IsDynamic() { return m_pInterface ? m_pInterface->usDynamicIndex != MODEL_PROPERTIES_GROUP_STATIC : false; };
 
 private:
     void CopyStreamingInfoFromModel(ushort usCopyFromModelID);
diff --git a/Client/mods/deathmatch/logic/CClientBuildingManager.cpp b/Client/mods/deathmatch/logic/CClientBuildingManager.cpp
index 243917b89f..a09df6a226 100644
--- a/Client/mods/deathmatch/logic/CClientBuildingManager.cpp
+++ b/Client/mods/deathmatch/logic/CClientBuildingManager.cpp
@@ -73,11 +73,6 @@ bool CClientBuildingManager::IsValidModel(uint16_t modelId)
     if (!pModelInfo->IsAllocatedInArchive())
         return false;
 
-    if (pModelInfo->IsDynamic())
-    {
-        return false;
-    }
-
     eModelInfoType eType = pModelInfo->GetModelType();
     return (eType == eModelInfoType::CLUMP || eType == eModelInfoType::ATOMIC || eType == eModelInfoType::WEAPON || eType == eModelInfoType::TIME);
 }
@@ -106,29 +101,9 @@ void CClientBuildingManager::RestoreDestroyed()
         {
             const CClientBuilding* highLodBuilding = building->GetHighLodBuilding();
             if (highLodBuilding && !highLodBuilding->IsValid())
-            {
                 hasInvalidLods = true;
-            }
             else
-            {
-                CModelInfo* modelInfo = building->GetModelInfo();
-                const uint16_t physicalGroup = modelInfo->GetObjectPropertiesGroup();
-
-                if (physicalGroup == -1)
-                {
-                    building->Create();
-                }
-                else
-                {
-                    // GTA creates dynamic models as dummies.
-                    // It's possible that the physical group was changes after
-                    // creating a new building. We can avoid crashes in this case.
-                    modelInfo->SetObjectPropertiesGroup(-1);
-                    building->Create();
-                    modelInfo->SetObjectPropertiesGroup(physicalGroup);
-                }
-                
-            }
+                building->Create();
         }
     }
 }
diff --git a/Client/sdk/game/CModelInfo.h b/Client/sdk/game/CModelInfo.h
index 08cb032e4c..3541750038 100644
--- a/Client/sdk/game/CModelInfo.h
+++ b/Client/sdk/game/CModelInfo.h
@@ -15,6 +15,8 @@
 #include "CAnimBlock.h"
 #include "Common.h"
 
+constexpr std::uint16_t MODEL_PROPERTIES_GROUP_STATIC = 0xFFFF;
+
 class CBaseModelInfoSAInterface;
 class CColModel;
 class CPedModelInfo;
@@ -131,6 +133,7 @@ struct SVehicleSupportedUpgrades
     bool m_bMisc;
     bool m_bInitialised;
 };
+
 class CModelInfo
 {
 public: