From df3c925b3ccae3bdba125e6dc3ecc740739baeab Mon Sep 17 00:00:00 2001
From: MirceaKitsune <sonichedgehog_hyperblast00@yahoo.com>
Date: Fri, 8 Feb 2013 22:54:01 +0200
Subject: [PATCH] Improved Player Physics

---
 minetest.conf.example   |  15 ++++
 src/client.cpp          |  20 +++++
 src/clientserver.h      |  17 ++++
 src/defaultsettings.cpp |  14 +++
 src/environment.cpp     |  41 ++++++---
 src/localplayer.cpp     | 186 ++++++++++++++++++++++------------------
 src/player.cpp          |  58 +++++++++++--
 src/player.h            |  25 ++++--
 src/server.cpp          |  29 +++++++
 src/server.h            |   1 +
 10 files changed, 296 insertions(+), 110 deletions(-)

diff --git a/minetest.conf.example b/minetest.conf.example
index 49fc95ba2..295725876 100644
--- a/minetest.conf.example
+++ b/minetest.conf.example
@@ -245,6 +245,21 @@
 # Files that are not present would be fetched the usual way
 #remote_media =
 
+# Physics stuff
+#movement_acceleration_default = 2
+#movement_acceleration_air = 0.5
+#movement_acceleration_fast = 4
+#movement_speed_walk = 4
+#movement_speed_crouch = 1.35
+#movement_speed_fast = 20
+#movement_speed_climb = 2
+#movement_speed_jump = 6.5
+#movement_speed_descend = 6
+#movement_liquid_fluidity = 1
+#movement_liquid_fluidity_smooth = 0.5
+#movement_liquid_sink = 10
+#movement_gravity = 9.81
+
 # Mapgen stuff
 #mg_name = v6
 #water_level = 1
diff --git a/src/client.cpp b/src/client.cpp
index 9969ef538..415f07311 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -1514,6 +1514,26 @@ void Client::ProcessData(u8 *data, u32 datasize, u16 sender_peer_id)
 			}
 		}
 	}
+	else if(command == TOCLIENT_MOVEMENT)
+	{
+		std::string datastring((char*)&data[2], datasize-2);
+		std::istringstream is(datastring, std::ios_base::binary);
+		Player *player = m_env.getLocalPlayer();
+		assert(player != NULL);
+
+		player->movement_acceleration_default = readF1000(is) * BS;
+		player->movement_acceleration_air = readF1000(is) * BS;
+		player->movement_acceleration_fast = readF1000(is) * BS;
+		player->movement_speed_walk = readF1000(is) * BS;
+		player->movement_speed_crouch = readF1000(is) * BS;
+		player->movement_speed_fast = readF1000(is) * BS;
+		player->movement_speed_climb = readF1000(is) * BS;
+		player->movement_speed_jump = readF1000(is) * BS;
+		player->movement_liquid_fluidity = readF1000(is) * BS;
+		player->movement_liquid_fluidity_smooth = readF1000(is) * BS;
+		player->movement_liquid_sink = readF1000(is) * BS;
+		player->movement_gravity = readF1000(is) * BS;
+	}
 	else if(command == TOCLIENT_HP)
 	{
 		std::string datastring((char*)&data[2], datasize-2);
diff --git a/src/clientserver.h b/src/clientserver.h
index 52b9dc7b0..7fb3e83d2 100644
--- a/src/clientserver.h
+++ b/src/clientserver.h
@@ -364,6 +364,23 @@ enum ToClientCommand
 		u16 len
 		u8[len] formname
 	*/
+
+	TOCLIENT_MOVEMENT = 0x45,
+	/*
+		u16 command
+		f1000 movement_acceleration_default
+		f1000 movement_acceleration_air
+		f1000 movement_acceleration_fast
+		f1000 movement_speed_walk
+		f1000 movement_speed_crouch
+		f1000 movement_speed_fast
+		f1000 movement_speed_climb
+		f1000 movement_speed_jump
+		f1000 movement_liquid_fluidity
+		f1000 movement_liquid_fluidity_smooth
+		f1000 movement_liquid_sink
+		f1000 movement_gravity
+	*/
 };
 
 enum ToServerCommand
diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp
index a164d0693..1c673f76c 100644
--- a/src/defaultsettings.cpp
+++ b/src/defaultsettings.cpp
@@ -172,6 +172,20 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("congestion_control_max_rate", "400");
 	settings->setDefault("congestion_control_min_rate", "10");
 	settings->setDefault("remote_media", "");
+
+	// physics stuff
+	settings->setDefault("movement_acceleration_default", "2");
+	settings->setDefault("movement_acceleration_air", "0.5");
+	settings->setDefault("movement_acceleration_fast", "8");
+	settings->setDefault("movement_speed_walk", "4");
+	settings->setDefault("movement_speed_crouch", "1.35");
+	settings->setDefault("movement_speed_fast", "20");
+	settings->setDefault("movement_speed_climb", "2");
+	settings->setDefault("movement_speed_jump", "6.5");
+	settings->setDefault("movement_liquid_fluidity", "1");
+	settings->setDefault("movement_liquid_fluidity_smooth", "0.5");
+	settings->setDefault("movement_liquid_sink", "10");
+	settings->setDefault("movement_gravity", "9.81");
 	
 	//mapgen related things
 	settings->setDefault("mg_name", "v6");
diff --git a/src/environment.cpp b/src/environment.cpp
index 51255b918..ebf5e9a63 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -2065,20 +2065,37 @@ void ClientEnvironment::step(float dtime)
 			{
 				// Gravity
 				v3f speed = lplayer->getSpeed();
-				if(lplayer->swimming_up == false)
-					speed.Y -= 9.81 * BS * dtime_part * 2;
+				if(lplayer->in_liquid == false)
+					speed.Y -= lplayer->movement_gravity * dtime_part * 2;
 
-				// Water resistance
-				if(lplayer->in_water_stable || lplayer->in_water)
-				{
-					f32 max_down = 2.0*BS;
-					if(speed.Y < -max_down) speed.Y = -max_down;
+				// Liquid floating / sinking
+				if(lplayer->in_liquid && !lplayer->swimming_vertical)
+					speed.Y -= lplayer->movement_liquid_sink * dtime_part * 2;
 
-					f32 max = 2.5*BS;
-					if(speed.getLength() > max)
-					{
-						speed = speed / speed.getLength() * max;
-					}
+				// Liquid resistance
+				if(lplayer->in_liquid_stable || lplayer->in_liquid)
+				{
+					// How much the node's viscosity blocks movement, ranges between 0 and 1
+					// Should match the scale at which viscosity increase affects other liquid attributes
+					const f32 viscosity_factor = 0.3;
+
+					v3f d_wanted = -speed / lplayer->movement_liquid_fluidity;
+					f32 dl = d_wanted.getLength();
+					if(dl > lplayer->movement_liquid_fluidity_smooth)
+						dl = lplayer->movement_liquid_fluidity_smooth;
+					dl *= (lplayer->liquid_viscosity * viscosity_factor) + (1 - viscosity_factor);
+					
+					v3f d = d_wanted.normalize() * dl;
+					speed += d;
+					
+#if 0 // old code
+					if(speed.X > lplayer->movement_liquid_fluidity + lplayer->movement_liquid_fluidity_smooth)	speed.X -= lplayer->movement_liquid_fluidity_smooth;
+					if(speed.X < -lplayer->movement_liquid_fluidity - lplayer->movement_liquid_fluidity_smooth)	speed.X += lplayer->movement_liquid_fluidity_smooth;
+					if(speed.Y > lplayer->movement_liquid_fluidity + lplayer->movement_liquid_fluidity_smooth)	speed.Y -= lplayer->movement_liquid_fluidity_smooth;
+					if(speed.Y < -lplayer->movement_liquid_fluidity - lplayer->movement_liquid_fluidity_smooth)	speed.Y += lplayer->movement_liquid_fluidity_smooth;
+					if(speed.Z > lplayer->movement_liquid_fluidity + lplayer->movement_liquid_fluidity_smooth)	speed.Z -= lplayer->movement_liquid_fluidity_smooth;
+					if(speed.Z < -lplayer->movement_liquid_fluidity - lplayer->movement_liquid_fluidity_smooth)	speed.Z += lplayer->movement_liquid_fluidity_smooth;
+#endif
 				}
 
 				lplayer->setSpeed(speed);
diff --git a/src/localplayer.cpp b/src/localplayer.cpp
index 2d0d77140..8b6d7e2f6 100644
--- a/src/localplayer.cpp
+++ b/src/localplayer.cpp
@@ -90,37 +90,39 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 	*/
 	
 	/*
-		Check if player is in water (the oscillating value)
+		Check if player is in liquid (the oscillating value)
 	*/
 	try{
-		// If in water, the threshold of coming out is at higher y
-		if(in_water)
+		// If in liquid, the threshold of coming out is at higher y
+		if(in_liquid)
 		{
 			v3s16 pp = floatToInt(position + v3f(0,BS*0.1,0), BS);
-			in_water = nodemgr->get(map.getNode(pp).getContent()).isLiquid();
+			in_liquid = nodemgr->get(map.getNode(pp).getContent()).isLiquid();
+			liquid_viscosity = nodemgr->get(map.getNode(pp).getContent()).liquid_viscosity;
 		}
-		// If not in water, the threshold of going in is at lower y
+		// If not in liquid, the threshold of going in is at lower y
 		else
 		{
 			v3s16 pp = floatToInt(position + v3f(0,BS*0.5,0), BS);
-			in_water = nodemgr->get(map.getNode(pp).getContent()).isLiquid();
+			in_liquid = nodemgr->get(map.getNode(pp).getContent()).isLiquid();
+			liquid_viscosity = nodemgr->get(map.getNode(pp).getContent()).liquid_viscosity;
 		}
 	}
 	catch(InvalidPositionException &e)
 	{
-		in_water = false;
+		in_liquid = false;
 	}
 
 	/*
-		Check if player is in water (the stable value)
+		Check if player is in liquid (the stable value)
 	*/
 	try{
 		v3s16 pp = floatToInt(position + v3f(0,0,0), BS);
-		in_water_stable = nodemgr->get(map.getNode(pp).getContent()).isLiquid();
+		in_liquid_stable = nodemgr->get(map.getNode(pp).getContent()).isLiquid();
 	}
 	catch(InvalidPositionException &e)
 	{
-		in_water_stable = false;
+		in_liquid_stable = false;
 	}
 
 	/*
@@ -159,7 +161,7 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 		If sneaking, keep in range from the last walked node and don't
 		fall off from it
 	*/
-	if(control.sneak && m_sneak_node_exists && !(fly_allowed && g_settings->getBool("free_move")))
+	if(control.sneak && m_sneak_node_exists && !(fly_allowed && g_settings->getBool("free_move")) && !in_liquid)
 	{
 		f32 maxd = 0.5*BS + sneak_max;
 		v3f lwn_f = intToFloat(m_sneak_node, BS);
@@ -315,7 +317,7 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 	}
 
 	if(bouncy_jump && control.jump){
-		m_speed.Y += 6.5*BS;
+		m_speed.Y += movement_speed_jump*BS;
 		touching_ground = false;
 		MtEvent *e = new SimpleTriggerEvent("PlayerJump");
 		m_gamedef->event()->put(e);
@@ -348,7 +350,7 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 	*/
 	const ContentFeatures &f = nodemgr->get(map.getNodeNoEx(getStandingNodePos()));
 	// Determine if jumping is possible
-	m_can_jump = touching_ground;
+	m_can_jump = touching_ground && !in_liquid;
 	if(itemgroup_get(f.groups, "disable_jump"))
 		m_can_jump = false;
 }
@@ -361,12 +363,8 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d)
 void LocalPlayer::applyControl(float dtime)
 {
 	// Clear stuff
-	swimming_up = false;
+	swimming_vertical = false;
 
-	// Random constants
-	f32 walk_acceleration = 4.0 * BS;
-	f32 walkspeed_max = 4.0 * BS;
-	
 	setPitch(control.pitch);
 	setYaw(control.yaw);
 
@@ -380,22 +378,17 @@ void LocalPlayer::applyControl(float dtime)
 	v3f move_direction = v3f(0,0,1);
 	move_direction.rotateXZBy(getYaw());
 	
-	v3f speed = v3f(0,0,0);
+	v3f speedH = v3f(0,0,0); // Horizontal (X, Z)
+	v3f speedV = v3f(0,0,0); // Vertical (Y)
 	
 	bool fly_allowed = m_gamedef->checkLocalPrivilege("fly");
 	bool fast_allowed = m_gamedef->checkLocalPrivilege("fast");
 
 	bool free_move = fly_allowed && g_settings->getBool("free_move");
 	bool fast_move = fast_allowed && g_settings->getBool("fast_move");
+	bool fast_or_aux1_descends = (fast_move && control.aux1) || (fast_move && g_settings->getBool("aux1_descends"));
 	bool continuous_forward = g_settings->getBool("continuous_forward");
 
-	if(free_move || is_climbing)
-	{
-		v3f speed = getSpeed();
-		speed.Y = 0;
-		setSpeed(speed);
-	}
-
 	// Whether superspeed mode is used or not
 	bool superspeed = false;
 	
@@ -415,18 +408,21 @@ void LocalPlayer::applyControl(float dtime)
 			if(free_move)
 			{
 				// In free movement mode, aux1 descends
-				v3f speed = getSpeed();
 				if(fast_move)
-					speed.Y = -20*BS;
+					speedV.Y = -movement_speed_fast;
 				else
-					speed.Y = -walkspeed_max;
-				setSpeed(speed);
+					speedV.Y = -movement_speed_walk;
+			}
+			else if(in_liquid || in_liquid_stable)
+			{
+				// Always use fast when aux1_descends & fast_move are enabled in liquid, since the aux1 button would mean both turbo and "swim down" causing a conflict
+				speedV.Y = -movement_speed_fast;
+				swimming_vertical = true;
 			}
 			else if(is_climbing)
 			{
-					v3f speed = getSpeed();
-				speed.Y = -3*BS;
-				setSpeed(speed);
+				// Always use fast when aux1_descends & fast_move are enabled when climbing, since the aux1 button would mean both turbo and "descend" causing a conflict
+				speedV.Y = -movement_speed_fast;
 			}
 			else
 			{
@@ -456,66 +452,69 @@ void LocalPlayer::applyControl(float dtime)
 			if(free_move)
 			{
 				// In free movement mode, sneak descends
-				v3f speed = getSpeed();
-				if(fast_move && (control.aux1 ||
-						g_settings->getBool("always_fly_fast")))
-					speed.Y = -20*BS;
+				if(fast_move && (control.aux1 || g_settings->getBool("always_fly_fast")))
+					speedV.Y = -movement_speed_fast;
 				else
-					speed.Y = -walkspeed_max;
-					setSpeed(speed);
+					speedV.Y = -movement_speed_walk;
+			}
+			else if(in_liquid || in_liquid_stable)
+			{
+				if(fast_or_aux1_descends)
+					// Always use fast when aux1_descends & fast_move are enabled in liquid, since the aux1 button would mean both turbo and "swim down" causing a conflict
+					speedV.Y = -movement_speed_fast;
+				else
+					speedV.Y = -movement_speed_walk;
+				swimming_vertical = true;
 			}
 			else if(is_climbing)
 			{
-				v3f speed = getSpeed();
-				speed.Y = -3*BS;
-				setSpeed(speed);
+				if(fast_or_aux1_descends)
+					// Always use fast when aux1_descends & fast_move are enabled when climbing, since the aux1 button would mean both turbo and "descend" causing a conflict
+					speedV.Y = -movement_speed_fast;
+				else
+					speedV.Y = -movement_speed_climb;
 			}
 		}
 	}
 
 	if(continuous_forward)
-		speed += move_direction;
+		speedH += move_direction;
 
 	if(control.up)
 	{
 		if(continuous_forward)
 			superspeed = true;
 		else
-			speed += move_direction;
+			speedH += move_direction;
 	}
 	if(control.down)
 	{
-		speed -= move_direction;
+		speedH -= move_direction;
 	}
 	if(control.left)
 	{
-		speed += move_direction.crossProduct(v3f(0,1,0));
+		speedH += move_direction.crossProduct(v3f(0,1,0));
 	}
 	if(control.right)
 	{
-		speed += move_direction.crossProduct(v3f(0,-1,0));
+		speedH += move_direction.crossProduct(v3f(0,-1,0));
 	}
 	if(control.jump)
 	{
 		if(free_move)
-		{
-			v3f speed = getSpeed();
-			
-			if(g_settings->getBool("aux1_descends") ||
-					g_settings->getBool("always_fly_fast"))
+		{			
+			if(g_settings->getBool("aux1_descends") || g_settings->getBool("always_fly_fast"))
 			{
 				if(fast_move)
-					speed.Y = 20*BS;
+					speedV.Y = movement_speed_fast;
 				else
-					speed.Y = walkspeed_max;
+					speedV.Y = movement_speed_walk;
 			} else {
 				if(fast_move && control.aux1)
-					speed.Y = 20*BS;
+					speedV.Y = movement_speed_fast;
 				else
-					speed.Y = walkspeed_max;
+					speedV.Y = movement_speed_walk;
 			}
-			
-			setSpeed(speed);
 		}
 		else if(m_can_jump)
 		{
@@ -524,49 +523,66 @@ void LocalPlayer::applyControl(float dtime)
 				raising the height at which the jump speed is kept
 				at its starting value
 			*/
-			v3f speed = getSpeed();
-			if(speed.Y >= -0.5*BS)
+			v3f speedJ = getSpeed();
+			if(speedJ.Y >= -0.5 * BS)
 			{
-				speed.Y = 6.5*BS;
-				setSpeed(speed);
+				speedJ.Y = movement_speed_jump;
+				setSpeed(speedJ);
 				
 				MtEvent *e = new SimpleTriggerEvent("PlayerJump");
 				m_gamedef->event()->put(e);
 			}
 		}
-		// Use the oscillating value for getting out of water
-		// (so that the player doesn't fly on the surface)
-		else if(in_water)
+		else if(in_liquid)
 		{
-			v3f speed = getSpeed();
-			speed.Y = 1.5*BS;
-			setSpeed(speed);
-			swimming_up = true;
+			if(fast_or_aux1_descends)
+				// Always use fast when aux1_descends & fast_move are enabled in liquid, since the aux1 button would mean both turbo and "swim down" causing a conflict
+				speedV.Y = movement_speed_fast;
+			else
+				speedV.Y = movement_speed_walk;
+			swimming_vertical = true;
 		}
 		else if(is_climbing)
 		{
-	                v3f speed = getSpeed();
-			speed.Y = 3*BS;
-			setSpeed(speed);
+			if(fast_or_aux1_descends)
+				// Always use fast when aux1_descends & fast_move are enabled when climbing, since the aux1 button would mean both turbo and "descend" causing a conflict
+				speedV.Y = movement_speed_fast;
+			else
+				speedV.Y = movement_speed_climb;
 		}
 	}
 
 	// The speed of the player (Y is ignored)
-	if(superspeed)
-		speed = speed.normalize() * walkspeed_max * 5.0;
-	else if(control.sneak && !free_move)
-		speed = speed.normalize() * walkspeed_max / 3.0;
+	if(superspeed || (is_climbing && fast_or_aux1_descends) || ((in_liquid || in_liquid_stable) && fast_or_aux1_descends))
+		speedH = speedH.normalize() * movement_speed_fast;
+	else if(control.sneak && !free_move && !in_liquid && !in_liquid_stable)
+		speedH = speedH.normalize() * movement_speed_crouch;
 	else
-		speed = speed.normalize() * walkspeed_max;
-	
-	f32 inc = walk_acceleration * BS * dtime;
-	
-	// Faster acceleration if fast and free movement
-	if(free_move && fast_move && superspeed)
-		inc = walk_acceleration * BS * dtime * 10;
-	
+		speedH = speedH.normalize() * movement_speed_walk;
+
+	// Acceleration increase
+	f32 incH = 0; // Horizontal (X, Z)
+	f32 incV = 0; // Vertical (Y)
+	if((!touching_ground && !free_move && !is_climbing && !in_liquid) || (!free_move && m_can_jump && control.jump))
+	{
+		// Jumping and falling
+		if(superspeed || (fast_move && control.aux1))
+			incH = movement_acceleration_fast * BS * dtime;
+		else
+			incH = movement_acceleration_air * BS * dtime;
+		incV = 0; // No vertical acceleration in air
+	}
+	else if(superspeed || (fast_move && control.aux1))
+		incH = incV = movement_acceleration_fast * BS * dtime;
+	else if ((in_liquid || in_liquid_stable) && fast_or_aux1_descends)
+		// Always use fast when aux1_descends & fast_move are enabled in liquid, since the aux1 button would mean both turbo and "swim down" causing a conflict
+		incH = incV = movement_acceleration_fast * BS * dtime;
+	else
+		incH = incV = movement_acceleration_default * BS * dtime;
+
 	// Accelerate to target speed with maximum increment
-	accelerate(speed, inc);
+	accelerateHorizontal(speedH, incH);
+	accelerateVertical(speedV, incV);
 }
 
 v3s16 LocalPlayer::getStandingNodePos()
diff --git a/src/player.cpp b/src/player.cpp
index 36f12c77b..0c34c4cdf 100644
--- a/src/player.cpp
+++ b/src/player.cpp
@@ -27,10 +27,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 Player::Player(IGameDef *gamedef):
 	touching_ground(false),
-	in_water(false),
-	in_water_stable(false),
+	in_liquid(false),
+	in_liquid_stable(false),
+	liquid_viscosity(0),
 	is_climbing(false),
-	swimming_up(false),
+	swimming_vertical(false),
 	camera_barely_in_ceiling(false),
 	inventory(gamedef->idef()),
 	hp(PLAYER_MAX_HP),
@@ -56,19 +57,35 @@ Player::Player(IGameDef *gamedef):
 		"list[current_player;main;0,3.5;8,4;]"
 		"list[current_player;craft;3,0;3,3;]"
 		"list[current_player;craftpreview;7,1;1,1;]";
+
+	// Initialize movement settings at default values, so movement can work if the server fails to send them
+	movement_acceleration_default = 2 * BS;
+	movement_acceleration_air = 0.5 * BS;
+	movement_acceleration_fast = 8 * BS;
+	movement_speed_walk = 4 * BS;
+	movement_speed_crouch = 1.35 * BS;
+	movement_speed_fast = 20 * BS;
+	movement_speed_climb = 2 * BS;
+	movement_speed_jump = 6.5 * BS;
+	movement_liquid_fluidity = 1 * BS;
+	movement_liquid_fluidity_smooth = 0.5 * BS;
+	movement_liquid_sink = 10 * BS;
+	movement_gravity = 9.81 * BS;
 }
 
 Player::~Player()
 {
 }
 
-// Y direction is ignored
-void Player::accelerate(v3f target_speed, f32 max_increase)
+// Horizontal acceleration (X and Z), Y direction is ignored
+void Player::accelerateHorizontal(v3f target_speed, f32 max_increase)
 {
+	if(max_increase == 0)
+		return;
+
 	v3f d_wanted = target_speed - m_speed;
 	d_wanted.Y = 0;
-	f32 dl_wanted = d_wanted.getLength();
-	f32 dl = dl_wanted;
+	f32 dl = d_wanted.getLength();
 	if(dl > max_increase)
 		dl = max_increase;
 	
@@ -76,7 +93,6 @@ void Player::accelerate(v3f target_speed, f32 max_increase)
 
 	m_speed.X += d.X;
 	m_speed.Z += d.Z;
-	//m_speed += d;
 
 #if 0 // old code
 	if(m_speed.X < target_speed.X - max_increase)
@@ -99,6 +115,32 @@ void Player::accelerate(v3f target_speed, f32 max_increase)
 #endif
 }
 
+// Vertical acceleration (Y), X and Z directions are ignored
+void Player::accelerateVertical(v3f target_speed, f32 max_increase)
+{
+	if(max_increase == 0)
+		return;
+
+	f32 d_wanted = target_speed.Y - m_speed.Y;
+	if(d_wanted > max_increase)
+		d_wanted = max_increase;
+	else if(d_wanted < -max_increase)
+		d_wanted = -max_increase;
+
+	m_speed.Y += d_wanted;
+
+#if 0 // old code
+	if(m_speed.Y < target_speed.Y - max_increase)
+		m_speed.Y += max_increase;
+	else if(m_speed.Y > target_speed.Y + max_increase)
+		m_speed.Y -= max_increase;
+	else if(m_speed.Y < target_speed.Y)
+		m_speed.Y = target_speed.Y;
+	else if(m_speed.Y > target_speed.Y)
+		m_speed.Y = target_speed.Y;
+#endif
+}
+
 v3s16 Player::getLightPosition() const
 {
 	return floatToInt(m_position + v3f(0,BS+BS/2,0), BS);
diff --git a/src/player.h b/src/player.h
index 67b02c344..770afdb37 100644
--- a/src/player.h
+++ b/src/player.h
@@ -108,8 +108,8 @@ class Player
 		m_speed = speed;
 	}
 	
-	// Y direction is ignored
-	void accelerate(v3f target_speed, f32 max_increase);
+	void accelerateHorizontal(v3f target_speed, f32 max_increase);
+	void accelerateVertical(v3f target_speed, f32 max_increase);
 
 	v3f getPosition()
 	{
@@ -196,17 +196,32 @@ class Player
 
 	bool touching_ground;
 	// This oscillates so that the player jumps a bit above the surface
-	bool in_water;
+	bool in_liquid;
 	// This is more stable and defines the maximum speed of the player
-	bool in_water_stable;
+	bool in_liquid_stable;
+	// Gets the viscosity of water to calculate friction
+	u8 liquid_viscosity;
 	bool is_climbing;
-	bool swimming_up;
+	bool swimming_vertical;
 	bool camera_barely_in_ceiling;
 	
 	u8 light;
 
 	Inventory inventory;
 
+	f32 movement_acceleration_default;
+	f32 movement_acceleration_air;
+	f32 movement_acceleration_fast;
+	f32 movement_speed_walk;
+	f32 movement_speed_crouch;
+	f32 movement_speed_fast;
+	f32 movement_speed_climb;
+	f32 movement_speed_jump;
+	f32 movement_liquid_fluidity;
+	f32 movement_liquid_fluidity_smooth;
+	f32 movement_liquid_sink;
+	f32 movement_gravity;
+
 	u16 hp;
 
 	float hurt_tilt_timer;
diff --git a/src/server.cpp b/src/server.cpp
index a8640ad10..572ef4d82 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -2344,6 +2344,9 @@ void Server::ProcessData(u8 *data, u32 datasize, u16 peer_id)
 		infostream<<"Server: Sending content to "
 				<<getPlayerName(peer_id)<<std::endl;
 
+		// Send player movement settings
+		SendMovement(m_con, peer_id);
+
 		// Send item definitions
 		SendItemDef(m_con, peer_id, m_itemdef);
 
@@ -3534,6 +3537,32 @@ void Server::deletingPeer(con::Peer *peer, bool timeout)
 	Static send methods
 */
 
+void Server::SendMovement(con::Connection &con, u16 peer_id)
+{
+	DSTACK(__FUNCTION_NAME);
+	std::ostringstream os(std::ios_base::binary);
+
+	writeU16(os, TOCLIENT_MOVEMENT);
+	writeF1000(os, g_settings->getFloat("movement_acceleration_default"));
+	writeF1000(os, g_settings->getFloat("movement_acceleration_air"));
+	writeF1000(os, g_settings->getFloat("movement_acceleration_fast"));
+	writeF1000(os, g_settings->getFloat("movement_speed_walk"));
+	writeF1000(os, g_settings->getFloat("movement_speed_crouch"));
+	writeF1000(os, g_settings->getFloat("movement_speed_fast"));
+	writeF1000(os, g_settings->getFloat("movement_speed_climb"));
+	writeF1000(os, g_settings->getFloat("movement_speed_jump"));
+	writeF1000(os, g_settings->getFloat("movement_liquid_fluidity"));
+	writeF1000(os, g_settings->getFloat("movement_liquid_fluidity_smooth"));
+	writeF1000(os, g_settings->getFloat("movement_liquid_sink"));
+	writeF1000(os, g_settings->getFloat("movement_gravity"));
+
+	// Make data buffer
+	std::string s = os.str();
+	SharedBuffer<u8> data((u8*)s.c_str(), s.size());
+	// Send as reliable
+	con.Send(peer_id, 0, data, true);
+}
+
 void Server::SendHP(con::Connection &con, u16 peer_id, u8 hp)
 {
 	DSTACK(__FUNCTION_NAME);
diff --git a/src/server.h b/src/server.h
index 86d5513d8..29d47337d 100644
--- a/src/server.h
+++ b/src/server.h
@@ -602,6 +602,7 @@ class Server : public con::PeerHandler, public MapEventReceiver,
 		Static send methods
 	*/
 
+	static void SendMovement(con::Connection &con, u16 peer_id);
 	static void SendHP(con::Connection &con, u16 peer_id, u8 hp);
 	static void SendAccessDenied(con::Connection &con, u16 peer_id,
 			const std::wstring &reason);
-- 
GitLab