From 369177aa8015d75f4cb18c65f435efc1f2a9e05a Mon Sep 17 00:00:00 2001
From: Perttu Ahola <celeron55@gmail.com>
Date: Sun, 16 Oct 2011 18:45:17 +0300
Subject: [PATCH] Better player damage prevention when falling on unloaded
 blocks, not involving getting stuck in there.

---
 src/environment.cpp |  9 ++-------
 src/player.cpp      | 29 ++++++++++-------------------
 src/player.h        |  1 -
 3 files changed, 12 insertions(+), 27 deletions(-)

diff --git a/src/environment.cpp b/src/environment.cpp
index d7bbadd..1d68412 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -1671,11 +1671,6 @@ void ClientEnvironment::step(float dtime)
 	*/
 	bool is_climbing = lplayer->is_climbing;
 	
-	/*
-		Check if the player is frozen (don't apply physics)
-	*/
-	bool is_frozen = lplayer->is_frozen;
-
 	f32 player_speed = 0.001; // just some small value
 	player_speed = lplayer->getSpeed().getLength();
 	
@@ -1733,7 +1728,7 @@ void ClientEnvironment::step(float dtime)
 			v3f lplayerpos = lplayer->getPosition();
 			
 			// Apply physics
-			if(free_move == false && is_climbing == false && is_frozen == false)
+			if(free_move == false && is_climbing == false)
 			{
 				// Gravity
 				v3f speed = lplayer->getSpeed();
@@ -1767,7 +1762,7 @@ void ClientEnvironment::step(float dtime)
 	while(dtime_downcount > 0.001);
 		
 	//std::cout<<"Looped "<<loopcount<<" times."<<std::endl;
-
+	
 	for(core::list<CollisionInfo>::Iterator
 			i = player_collisions.begin();
 			i != player_collisions.end(); i++)
diff --git a/src/player.cpp b/src/player.cpp
index 6a77425..7329118 100644
--- a/src/player.cpp
+++ b/src/player.cpp
@@ -33,7 +33,6 @@ Player::Player():
 	in_water_stable(false),
 	is_climbing(false),
 	swimming_up(false),
-	is_frozen(false),
 	inventory_backup(NULL),
 	craftresult_is_preview(true),
 	hp(20),
@@ -335,19 +334,8 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 	/*
 		Calculate new position
 	*/
-	if(is_frozen) {
-		// Still move very slowly so as not to feel all completely stuck
-		position += m_speed * dtime * 0.001;
-	}
-	else {
-		position += m_speed * dtime;
-	}
+	position += m_speed * dtime;
 	
-	/*
-		If the player enters an unloaded chunk this is set to true.
-	*/
-	is_frozen = false;
-
 	// Skip collision detection if a special movement mode is used
 	bool free_move = g_settings->getBool("free_move");
 	if(free_move)
@@ -505,6 +493,8 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 			<<pos_i.X<<","<<pos_i.Y<<","<<pos_i.Z
 			<<"):"<<std::endl;*/
 	
+	bool standing_on_unloaded = false;
+	
 	/*
 		Go through every node around the player
 	*/
@@ -512,6 +502,7 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 	for(s16 z = oldpos_i.Z - 1; z <= oldpos_i.Z + 1; z++)
 	for(s16 x = oldpos_i.X - 1; x <= oldpos_i.X + 1; x++)
 	{
+		bool is_unloaded = false;
 		try{
 			// Player collides into walkable nodes
 			if(content_walkable(map.getNode(v3s16(x,y,z)).getContent()) == false)
@@ -519,11 +510,9 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 		}
 		catch(InvalidPositionException &e)
 		{
-			if(!is_frozen) {
-				// freeze when entering unloaded areas
-				is_frozen = true;
-			}
-			continue;
+			is_unloaded = true;
+			// Doing nothing here will block the player from
+			// walking over map borders
 		}
 
 		core::aabbox3d<f32> nodebox = getNodeBox(v3s16(x,y,z), BS);
@@ -546,6 +535,8 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 				&& nodebox.MinEdge.Z+d < playerbox.MaxEdge.Z
 		){
 			touching_ground = true;
+			if(is_unloaded)
+				standing_on_unloaded = true;
 		}
 		
 		// If player doesn't intersect with node, ignore node.
@@ -727,7 +718,7 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 	if(collision_info)
 	{
 		// Report fall collision
-		if(old_speed.Y < m_speed.Y - 0.1)
+		if(old_speed.Y < m_speed.Y - 0.1 && !standing_on_unloaded)
 		{
 			CollisionInfo info;
 			info.t = COLLISION_FALL;
diff --git a/src/player.h b/src/player.h
index ce10019..a352c1b 100644
--- a/src/player.h
+++ b/src/player.h
@@ -150,7 +150,6 @@ public:
 	bool in_water_stable;
 	bool is_climbing;
 	bool swimming_up;
-	bool is_frozen;
 	
 	u8 light;