From 780df3d4c8c05a74b64af03b46794e6cbc65fa19 Mon Sep 17 00:00:00 2001
From: Mario <mario@smbclan.net>
Date: Sun, 23 Sep 2018 11:48:18 +1000
Subject: [PATCH] Fix unsticking so it uses the actual offset position rather
 than the entity's current position, also implement SV_CheckStuck for player
 unsticking to oldorigin

---
 qcsrc/common/physics/movetypes/movetypes.qc | 31 +++++++++++++++++----
 qcsrc/common/physics/movetypes/movetypes.qh |  8 +++++-
 qcsrc/common/physics/movetypes/walk.qc      |  2 +-
 3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/qcsrc/common/physics/movetypes/movetypes.qc b/qcsrc/common/physics/movetypes/movetypes.qc
index e518fe210..e31b4076b 100644
--- a/qcsrc/common/physics/movetypes/movetypes.qc
+++ b/qcsrc/common/physics/movetypes/movetypes.qc
@@ -406,11 +406,11 @@ entity _Movetype_TestEntityPosition_ent;
 bool _Movetype_TestEntityPosition(vector ofs)  // SV_TestEntityPosition
 {
     entity this = _Movetype_TestEntityPosition_ent;
-//	vector org = this.origin + ofs;
+	vector org = this.origin + ofs;
 
 	int cont = this.dphitcontentsmask;
 	this.dphitcontentsmask = DPCONTENTS_SOLID;
-	tracebox(this.origin, this.mins, this.maxs, this.origin, ((this.move_movetype == MOVETYPE_FLY_WORLDONLY) ? MOVE_WORLDONLY : MOVE_NOMONSTERS), this);
+	tracebox(org, this.mins, this.maxs, org, ((this.move_movetype == MOVETYPE_FLY_WORLDONLY) ? MOVE_WORLDONLY : MOVE_NOMONSTERS), this);
 	this.dphitcontentsmask = cont;
 
 	if(trace_startsolid)
@@ -421,11 +421,11 @@ bool _Movetype_TestEntityPosition(vector ofs)  // SV_TestEntityPosition
 	return false;
 }
 
-bool _Movetype_UnstickEntity(entity this)  // SV_UnstickEntity
+int _Movetype_UnstickEntity(entity this)  // SV_UnstickEntity
 {
     _Movetype_TestEntityPosition_ent = this;
 	if (!_Movetype_TestEntityPosition(' 0  0  0')) {
-	    return true;
+	    return UNSTICK_FINE;
 	}
 	#define X(v) if (_Movetype_TestEntityPosition(v))
 	X('-1  0  0') X(' 1  0  0')
@@ -444,13 +444,32 @@ bool _Movetype_UnstickEntity(entity this)  // SV_UnstickEntity
         {
             LOG_DEBUGF("Can't unstick an entity (edict: %d, classname: %s, origin: %s)",
                 etof(this), this.classname, vtos(this.origin));
-            return false;
+            return UNSTICK_STUCK;
         }
 	}
 	LOG_DEBUGF("Sucessfully unstuck an entity (edict: %d, classname: %s, origin: %s)",
 		etof(this), this.classname, vtos(this.origin));
 	_Movetype_LinkEdict(this, true);
-	return true;
+	return UNSTICK_FIXED;
+}
+
+void _Movetype_CheckStuck(entity this)  // SV_CheckStuck
+{
+	int unstick = _Movetype_UnstickEntity(this); // sets test position entity
+	switch(unstick)
+	{
+		case UNSTICK_FINE:
+			this.oldorigin = this.origin;
+			break;
+		case UNSTICK_FIXED:
+			break; // already sorted
+		case UNSTICK_STUCK:
+			vector offset = this.oldorigin - this.origin;
+			if(!_Movetype_TestEntityPosition(offset))
+				_Movetype_LinkEdict(this, false);
+			// couldn't unstick, should we warn about this?
+			break;
+	}
 }
 
 vector _Movetype_ClipVelocity(vector vel, vector norm, float f)  // SV_ClipVelocity
diff --git a/qcsrc/common/physics/movetypes/movetypes.qh b/qcsrc/common/physics/movetypes/movetypes.qh
index 36cbd9f46..62b7964d9 100644
--- a/qcsrc/common/physics/movetypes/movetypes.qh
+++ b/qcsrc/common/physics/movetypes/movetypes.qh
@@ -80,10 +80,16 @@ void set_movetype(entity this, int mt);
 .float move_suspendedinair;
 .float move_didgravity;
 
+// unsticking
+const int UNSTICK_FINE = 0;
+const int UNSTICK_FIXED = 1;
+const int UNSTICK_STUCK = 2;
+
 void _Movetype_WallFriction(entity this, vector stepnormal);
 int _Movetype_FlyMove(entity this, float dt, bool applygravity, vector stepnormal, float stepheight);
 void _Movetype_CheckVelocity(entity this);
 void _Movetype_CheckWaterTransition(entity ent);
+void _Movetype_CheckStuck(entity this);
 float _Movetype_CheckWater(entity ent);
 void _Movetype_LinkEdict_TouchAreaGrid(entity this);
 void _Movetype_LinkEdict(entity this, float touch_triggers);
@@ -98,7 +104,7 @@ void Movetype_Physics_NoMatchServer(entity this);
 void _Movetype_LinkEdict(entity this, float touch_triggers);
 void _Movetype_LinkEdict_TouchAreaGrid(entity this);
 
-float _Movetype_UnstickEntity(entity this);
+int _Movetype_UnstickEntity(entity this);
 
 const int MAX_CLIP_PLANES = 5;
 
diff --git a/qcsrc/common/physics/movetypes/walk.qc b/qcsrc/common/physics/movetypes/walk.qc
index d22b6d32a..c0f2fac96 100644
--- a/qcsrc/common/physics/movetypes/walk.qc
+++ b/qcsrc/common/physics/movetypes/walk.qc
@@ -8,7 +8,7 @@ void _Movetype_Physics_Walk(entity this, float dt)  // SV_WalkMove
 		return;
 
 	if (GAMEPLAYFIX_UNSTICKPLAYERS(this))
-		_Movetype_UnstickEntity(this);
+		_Movetype_CheckStuck(this);
 
 	bool applygravity = (!_Movetype_CheckWater(this) && this.move_movetype == MOVETYPE_WALK && !(this.flags & FL_WATERJUMP));
 
-- 
2.39.2