From 85c80ab0f2bb7ed7fcc20dba668bdcb1c3fb4786 Mon Sep 17 00:00:00 2001
From: Nuno <ulukyn@gmail.com>
Date: Fri, 26 Nov 2021 19:13:53 +0100
Subject: [PATCH] Smooth the z displacement of entities

---
 nel/include/nel/pacs/move_primitive.h   | 10 +++--
 nel/include/nel/pacs/u_move_primitive.h |  4 +-
 nel/src/pacs/move_container.cpp         |  3 +-
 ryzom/client/src/entity_cl.cpp          | 50 +++++++++++++++++++++++--
 ryzom/client/src/entity_cl.h            |  8 +++-
 5 files changed, 62 insertions(+), 13 deletions(-)

diff --git a/nel/include/nel/pacs/move_primitive.h b/nel/include/nel/pacs/move_primitive.h
index d77517a7d..928ed10fc 100644
--- a/nel/include/nel/pacs/move_primitive.h
+++ b/nel/include/nel/pacs/move_primitive.h
@@ -251,16 +251,17 @@ public:
 		_Height=height;
 	}
 
-	void setZOffset(float offset)
+	void setZFinalPosition(float pos)
 	{
-		_ZOffset = offset;
+		_ZFinalPosition = pos;
 	}
 
-	float getZOffset()
+	float getZFinalPosition()
 	{
-		return _ZOffset;
+		return _ZFinalPosition;
 	}
 
+
 	bool haveZOffset()
 	{
 		return _HaveZOffset;
@@ -489,6 +490,7 @@ private:
 	sint32				_IterationCount;
 
 	float 				_ZOffset;
+	float 				_ZFinalPosition;
 	bool				_HaveZOffset;
 
 };
diff --git a/nel/include/nel/pacs/u_move_primitive.h b/nel/include/nel/pacs/u_move_primitive.h
index e067c3e6b..cba266174 100644
--- a/nel/include/nel/pacs/u_move_primitive.h
+++ b/nel/include/nel/pacs/u_move_primitive.h
@@ -280,9 +280,9 @@ public:
 	  */
 	virtual float			getHeight () const =0;
 
-	virtual void setZOffset(float offset) =0;
+	virtual void setZFinalPosition(float pos) =0;
 
-	virtual float getZOffset() =0;
+	virtual float getZFinalPosition() =0;
 
 	virtual bool haveZOffset() =0;
 
diff --git a/nel/src/pacs/move_container.cpp b/nel/src/pacs/move_container.cpp
index 4d093ae6a..c313fefb9 100644
--- a/nel/src/pacs/move_container.cpp
+++ b/nel/src/pacs/move_container.cpp
@@ -1675,8 +1675,7 @@ void CMoveContainer::reaction (const CCollisionOTInfo& first)
 						dynInfo->getFirstPrimitive()->enableZOffset(true);
 						CVectorD first_pos = dynInfo->getFirstPrimitive()->getFinalPosition(dynInfo->getFirstWorldImage());
 						CVectorD second_pos = dynInfo->getSecondPrimitive()->getFinalPosition(dynInfo->getSecondWorldImage());
-						nlinfo("P = %f, C = %f, H = %f, D = %f", first_pos.z, second_pos.z, dynInfo->getSecondPrimitive()->getHeight(), second_pos.z-first_pos.z);
-						dynInfo->getFirstPrimitive()->setZOffset(second_pos.z+dynInfo->getSecondPrimitive()->getHeight()-10.0f);
+						dynInfo->getFirstPrimitive()->setZFinalPosition(second_pos.z+dynInfo->getSecondPrimitive()->getHeight()-10.0f);
 					}
 				}
 				if (dynInfo->isExit())
diff --git a/ryzom/client/src/entity_cl.cpp b/ryzom/client/src/entity_cl.cpp
index c523449a1..616363f0b 100644
--- a/ryzom/client/src/entity_cl.cpp
+++ b/ryzom/client/src/entity_cl.cpp
@@ -740,6 +740,8 @@ void CEntityCL::init()
 		_EntityName = "Name";
 	}
 	_NameId = 0;
+	_LastSnapToGroup = 0;
+	_CurrentZOffset = 0;
 
 	_PermanentStatutIcon.clear();
 
@@ -1481,6 +1483,17 @@ void CEntityCL::pacsMove(const CVectorD &vect)
 			_Primitive->enableZOffset(false);
 			_Primitive->move (deltaPos, dynamicWI);
 		}
+		else
+		{
+			// This code force the player to move even when not moving, it's used to trigger special collissions
+			if (isUser())
+			{
+				_HasMoved = true;
+				deltaPos.x = 0.0001;
+				_Primitive->move (deltaPos, dynamicWI);
+			}
+
+		}
 	}
 	else
 	{
@@ -1714,11 +1727,42 @@ void CEntityCL::snapToGround()
 		pos().z = vect.z;
 	}
 
-	if (_Primitive->haveZOffset()) {
-		//CVectorD prim_pos = _Primitive->getFinalPosition(dynamicWI);
-		pos().z = _Primitive->getZOffset();
+	if (_Primitive->haveZOffset())
+	{
+
+		if (_LastSnapToGroup > 0)
+		{
+			if (pos().z + _CurrentZOffset < _Primitive->getZFinalPosition())
+			{
+				_CurrentZOffset += (ryzomGetLocalTime() - _LastSnapToGroup)/100.0f;
+
+				if (pos().z + _CurrentZOffset > _Primitive->getZFinalPosition())
+					_CurrentZOffset = _Primitive->getZFinalPosition() - pos().z;
+			}
+
+			if (pos().z + _CurrentZOffset > _Primitive->getZFinalPosition())
+			{
+				_CurrentZOffset -= (ryzomGetLocalTime() - _LastSnapToGroup)/100.0f;
+
+				if (pos().z + _CurrentZOffset < _Primitive->getZFinalPosition())
+					_CurrentZOffset = _Primitive->getZFinalPosition() - pos().z;
+			}
+
+			pos().z += _CurrentZOffset;
+		}
 	}
+	else
+	{
+		if (_CurrentZOffset > 0)
+		{
+			_CurrentZOffset -= (ryzomGetLocalTime() - _LastSnapToGroup)/100.0f;
 
+			if (_CurrentZOffset < 0)
+				_CurrentZOffset = 0;
+			pos().z += _CurrentZOffset;
+		}
+	}
+	_LastSnapToGroup = ryzomGetLocalTime();
 
 	// Set the box position.
 	posBox(pos());
diff --git a/ryzom/client/src/entity_cl.h b/ryzom/client/src/entity_cl.h
index f2f99b347..092a85dd3 100644
--- a/ryzom/client/src/entity_cl.h
+++ b/ryzom/client/src/entity_cl.h
@@ -241,7 +241,7 @@ public:
 
 	/// Return the persistent NPC alias of entity (0 if N/A).
 	uint32 npcAlias() const {return _NPCAlias; }
-	/// Set the persistent NPC alias of the entity.	
+	/// Set the persistent NPC alias of the entity.
 	void npcAlias(uint32 alias) {_NPCAlias = alias; }
 
 	/// Method to call to initialize all members of the right class.
@@ -702,7 +702,7 @@ public:
 	// todo handle NPC entities
 	// Return true if this entity is a NPC (not a fauna)
 	bool isNPC () const { return Type == NPC; }
-	
+
 	// Return true if this entity can have missions icons (humanoid NPCs (including Karavan), Kami or Bot Object)
 	bool canHaveMissionIcon() const { return isNPC() || isKami() || isUnknownRace(); }
 
@@ -949,6 +949,10 @@ protected:
 	uint32							_NameId;
 	// Primitive used for the collision in PACS
 	NLPACS::UMovePrimitive			*_Primitive;
+
+	uint64 							_LastSnapToGroup;
+	float							_CurrentZOffset;
+
 	// 3D Logic info for light request.
 	CEntityLogicInfo3D				_LogicInfo3D;
 	// Box around the entity.