Allow modifying movement speed, jump height and gravity per-player via the Lua API.

doc/lua_api.txt

@@ -1348,6 +1348,10 @@ Player-only: (no-op for other objects)
     {jump=bool,right=bool,left=bool,LMB=bool,RMB=bool,sneak=bool,aux1=bool,down=bool,up=bool}
 - get_player_control_bits(): returns integer with bit packed player pressed keys
     bit nr/meaning: 0/up ,1/down ,2/left ,3/right ,4/jump ,5/aux1 ,6/sneak ,7/LMB ,8/RMB
+- set_physics_override(speed, jump, gravity)
+    modifies per-player walking speed, jump height, and gravity.
+    Values default to 1 and act as offsets to the physics settings 
+    in minetest.conf. nil will keep the current setting.
     
 InvRef: Reference to an inventory
 methods:

src/clientserver.h

@@ -88,9 +88,11 @@ SharedBuffer<u8> makePacket_TOCLIENT_TIME_OF_DAY(u16 time, float time_speed);
 	PROTOCOL_VERSION 18:
 		damageGroups added to ToolCapabilities
 		sound_place added to ItemDefinition
+	PROTOCOL_VERSION 19:
+		GENERIC_CMD_SET_PHYSICS_OVERRIDE
 */
 
-#define LATEST_PROTOCOL_VERSION 18
+#define LATEST_PROTOCOL_VERSION 19
 
 // Server's supported network protocol range
 #define SERVER_PROTOCOL_VERSION_MIN 13

src/content_cao.cpp

@@ -1679,6 +1679,19 @@ public:
 
 			updateTexturePos();
 		}
+		else if(cmd == GENERIC_CMD_SET_PHYSICS_OVERRIDE)
+		{
+			float override_speed = readF1000(is);
+			float override_jump = readF1000(is);
+			float override_gravity = readF1000(is);
+			if(m_is_local_player)
+			{
+				LocalPlayer *player = m_env->getLocalPlayer();
+				player->physics_override_speed = override_speed;
+				player->physics_override_jump = override_jump;
+				player->physics_override_gravity = override_gravity;
+			}
+		}
 		else if(cmd == GENERIC_CMD_SET_ANIMATION)
 		{
 			m_animation_range = readV2F1000(is);

src/content_sao.cpp

@@ -935,7 +935,11 @@ PlayerSAO::PlayerSAO(ServerEnvironment *env_, Player *player_, u16 peer_id_,
 	m_moved(false),
 	m_inventory_not_sent(false),
 	m_hp_not_sent(false),
-	m_wielded_item_not_sent(false)
+	m_wielded_item_not_sent(false),
+	m_physics_override_speed(1),
+	m_physics_override_jump(1),
+	m_physics_override_gravity(1),
+	m_physics_override_sent(false)
 {
 	assert(m_player);
 	assert(m_peer_id != 0);
@@ -1019,7 +1023,7 @@ std::string PlayerSAO::getClientInitializationData(u16 protocol_version)
 		writeF1000(os, m_player->getYaw());
 		writeS16(os, getHP());
 
-		writeU8(os, 4 + m_bone_position.size()); // number of messages stuffed in here
+		writeU8(os, 5 + m_bone_position.size()); // number of messages stuffed in here
 		os<<serializeLongString(getPropertyPacket()); // message 1
 		os<<serializeLongString(gob_cmd_update_armor_groups(m_armor_groups)); // 2
 		os<<serializeLongString(gob_cmd_update_animation(m_animation_range, m_animation_speed, m_animation_blend)); // 3
@@ -1027,6 +1031,7 @@ std::string PlayerSAO::getClientInitializationData(u16 protocol_version)
 			os<<serializeLongString(gob_cmd_update_bone_position((*ii).first, (*ii).second.X, (*ii).second.Y)); // m_bone_position.size
 		}
 		os<<serializeLongString(gob_cmd_update_attachment(m_attachment_parent_id, m_attachment_bone, m_attachment_position, m_attachment_rotation)); // 4
+		os<<serializeLongString(gob_cmd_update_physics_override(m_physics_override_speed, m_physics_override_jump, m_physics_override_gravity)); // 5
 	}
 	else
 	{
@@ -1196,6 +1201,14 @@ void PlayerSAO::step(float dtime, bool send_recommended)
 		m_messages_out.push_back(aom);
 	}
 
+	if(m_physics_override_sent == false){
+		m_physics_override_sent = true;
+		std::string str = gob_cmd_update_physics_override(m_physics_override_speed, m_physics_override_jump, m_physics_override_gravity);
+		// create message and add to list
+		ActiveObjectMessage aom(getId(), true, str);
+		m_messages_out.push_back(aom);
+	}
+
 	if(m_animation_sent == false){
 		m_animation_sent = true;
 		std::string str = gob_cmd_update_animation(m_animation_range, m_animation_speed, m_animation_blend);

src/content_sao.h

@@ -257,8 +257,6 @@ private:
 	ItemGroupList m_armor_groups;
 	bool m_armor_groups_sent;
 
-
-
 	bool m_properties_sent;
 	struct ObjectProperties m_prop;
 	// Cached privileges for enforcement
@@ -285,6 +283,11 @@ public:
 	bool m_inventory_not_sent;
 	bool m_hp_not_sent;
 	bool m_wielded_item_not_sent;
+
+	float m_physics_override_speed;
+	float m_physics_override_jump;
+	float m_physics_override_gravity;
+	bool m_physics_override_sent;
 };
 
 #endif

src/environment.cpp

@@ -2057,7 +2057,7 @@ void ClientEnvironment::step(float dtime)
 				// Gravity
 				v3f speed = lplayer->getSpeed();
 				if(lplayer->in_liquid == false)
-					speed.Y -= lplayer->movement_gravity * dtime_part * 2;
+					speed.Y -= lplayer->movement_gravity * lplayer->physics_override_gravity * dtime_part * 2;
 
 				// Liquid floating / sinking
 				if(lplayer->in_liquid && !lplayer->swimming_vertical)

src/genericobject.cpp

@@ -117,6 +117,18 @@ std::string gob_cmd_update_armor_groups(const ItemGroupList &armor_groups)
 	return os.str();
 }
 
+std::string gob_cmd_update_physics_override(float physics_override_speed, float physics_override_jump, float physics_override_gravity)
+{
+	std::ostringstream os(std::ios::binary);
+	// command 
+	writeU8(os, GENERIC_CMD_SET_PHYSICS_OVERRIDE);
+	// parameters
+	writeF1000(os, physics_override_speed);
+	writeF1000(os, physics_override_jump);
+	writeF1000(os, physics_override_gravity);
+	return os.str();
+}
+
 std::string gob_cmd_update_animation(v2f frames, float frame_speed, float frame_blend)
 {
 	std::ostringstream os(std::ios::binary);

src/genericobject.h

@@ -33,6 +33,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define GENERIC_CMD_SET_ANIMATION 6
 #define GENERIC_CMD_SET_BONE_POSITION 7
 #define GENERIC_CMD_SET_ATTACHMENT 8
+#define GENERIC_CMD_SET_PHYSICS_OVERRIDE 9
 
 #include "object_properties.h"
 std::string gob_cmd_set_properties(const ObjectProperties &prop);
@@ -62,6 +63,8 @@ std::string gob_cmd_punched(s16 damage, s16 result_hp);
 #include "itemgroup.h"
 std::string gob_cmd_update_armor_groups(const ItemGroupList &armor_groups);
 
+std::string gob_cmd_update_physics_override(float physics_override_speed, float physics_override_jump, float physics_override_gravity);
+
 std::string gob_cmd_update_animation(v2f frames, float frame_speed, float frame_blend);
 
 std::string gob_cmd_update_bone_position(std::string bone, v3f position, v3f rotation);

src/localplayer.cpp

@@ -529,7 +529,7 @@ void LocalPlayer::applyControl(float dtime)
 			v3f speedJ = getSpeed();
 			if(speedJ.Y >= -0.5 * BS)
 			{
-				speedJ.Y = movement_speed_jump;
+				speedJ.Y = movement_speed_jump * physics_override_jump;
 				setSpeed(speedJ);
 				
 				MtEvent *e = new SimpleTriggerEvent("PlayerJump");
@@ -584,8 +584,8 @@ void LocalPlayer::applyControl(float dtime)
 		incH = incV = movement_acceleration_default * BS * dtime;
 
 	// Accelerate to target speed with maximum increment
-	accelerateHorizontal(speedH, incH);
-	accelerateVertical(speedV, incV);
+	accelerateHorizontal(speedH * physics_override_speed, incH * physics_override_speed);
+	accelerateVertical(speedV * physics_override_speed, incV * physics_override_speed);
 }
 
 v3s16 LocalPlayer::getStandingNodePos()

src/player.cpp

@@ -71,6 +71,11 @@ Player::Player(IGameDef *gamedef):
 	movement_liquid_fluidity_smooth = 0.5 * BS;
 	movement_liquid_sink = 10 * BS;
 	movement_gravity = 9.81 * BS;
+
+	// Movement overrides are multipliers and must be 1 by default
+	physics_override_speed = 1;
+	physics_override_jump = 1;
+	physics_override_gravity = 1;
 }
 
 Player::~Player()

src/player.h

@@ -222,6 +222,10 @@ public:
 	f32 movement_liquid_sink;
 	f32 movement_gravity;
 
+	float physics_override_speed;
+	float physics_override_jump;
+	float physics_override_gravity;
+
 	u16 hp;
 
 	float hurt_tilt_timer;

src/scriptapi_object.cpp

@@ -297,6 +297,28 @@ int ObjectRef::l_set_armor_groups(lua_State *L)
 	return 0;
 }
 
+// set_physics_override(self, physics_override_speed, physics_override_jump, physics_override_gravity)
+int ObjectRef::l_set_physics_override(lua_State *L)
+{
+	ObjectRef *ref = checkobject(L, 1);
+	PlayerSAO *co = (PlayerSAO *) getobject(ref);
+	if(co == NULL) return 0;
+	// Do it
+	if(!lua_isnil(L, 2)){
+		co->m_physics_override_speed = lua_tonumber(L, 2);
+		co->m_physics_override_sent = false;
+	}
+	if(!lua_isnil(L, 3)){
+		co->m_physics_override_jump = lua_tonumber(L, 3);
+		co->m_physics_override_sent = false;
+	}
+	if(!lua_isnil(L, 4)){
+		co->m_physics_override_gravity = lua_tonumber(L, 4);
+		co->m_physics_override_sent = false;
+	}
+	return 0;
+}
+
 // set_animation(self, frame_range, frame_speed, frame_blend)
 int ObjectRef::l_set_animation(lua_State *L)
 {
@@ -756,6 +778,7 @@ const luaL_reg ObjectRef::methods[] = {
 	luamethod(ObjectRef, get_wielded_item),
 	luamethod(ObjectRef, set_wielded_item),
 	luamethod(ObjectRef, set_armor_groups),
+	luamethod(ObjectRef, set_physics_override),
 	luamethod(ObjectRef, set_animation),
 	luamethod(ObjectRef, set_bone_position),
 	luamethod(ObjectRef, set_attach),

src/scriptapi_object.h

@@ -103,6 +103,9 @@ private:
 	// set_armor_groups(self, groups)
 	static int l_set_armor_groups(lua_State *L);
 
+	// set_physics_override(self, physics_override_speed, physics_override_jump, physics_override_gravity)
+	static int l_set_physics_override(lua_State *L);
+
 	// set_animation(self, frame_range, frame_speed, frame_blend)
 	static int l_set_animation(lua_State *L);
 

src/serverobject.h

@@ -152,6 +152,8 @@ public:
 
 	virtual void setArmorGroups(const ItemGroupList &armor_groups)
 	{}
+	virtual void setPhysicsOverride(float physics_override_speed, float physics_override_jump, float physics_override_gravity)
+	{}
 	virtual void setAnimation(v2f frames, float frame_speed, float frame_blend)
 	{}
 	virtual void setBonePosition(std::string bone, v3f position, v3f rotation)