Move serveractiveobject & unitsao

Move serverobject.{cpp,h} to server/serveractiveobject.{cpp,h}
Move UnitSAO class to dedicated files

18 files changed, 442 insertions, 399 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4b1d6d647..faa117d41 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -421,7 +421,6 @@ set(common_SRCS
 	server.cpp
 	serverenvironment.cpp
 	serverlist.cpp
-	serverobject.cpp
 	settings.cpp
 	staticobject.cpp
 	terminal_chat_console.cpp
diff --git a/src/collision.cpp b/src/collision.cpp
index 0d37ea436..d9fbd3202 100644
--- a/src/collision.cpp
+++ b/src/collision.cpp
@@ -28,7 +28,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "client/localplayer.h"
 #endif
 #include "serverenvironment.h"
-#include "serverobject.h"
+#include "server/serveractiveobject.h"
 #include "util/timetaker.h"
 #include "profiler.h"
 
diff --git a/src/content_sao.cpp b/src/content_sao.cpp
index be7674f52..0d387b53a 100644
--- a/src/content_sao.cpp
+++ b/src/content_sao.cpp
@@ -107,302 +107,6 @@ private:
 TestSAO proto_TestSAO(NULL, v3f(0,0,0));
 
 /*
-	UnitSAO
- */
-
-UnitSAO::UnitSAO(ServerEnvironment *env, v3f pos):
-	ServerActiveObject(env, pos)
-{
-	// Initialize something to armor groups
-	m_armor_groups["fleshy"] = 100;
-}
-
-ServerActiveObject *UnitSAO::getParent() const
-{
-	if (!m_attachment_parent_id)
-		return nullptr;
-	// Check if the parent still exists
-	ServerActiveObject *obj = m_env->getActiveObject(m_attachment_parent_id);
-
-	return obj;
-}
-
-void UnitSAO::setArmorGroups(const ItemGroupList &armor_groups)
-{
-	m_armor_groups = armor_groups;
-	m_armor_groups_sent = false;
-}
-
-const ItemGroupList &UnitSAO::getArmorGroups() const
-{
-	return m_armor_groups;
-}
-
-void UnitSAO::setAnimation(v2f frame_range, float frame_speed, float frame_blend, bool frame_loop)
-{
-	// store these so they can be updated to clients
-	m_animation_range = frame_range;
-	m_animation_speed = frame_speed;
-	m_animation_blend = frame_blend;
-	m_animation_loop = frame_loop;
-	m_animation_sent = false;
-}
-
-void UnitSAO::getAnimation(v2f *frame_range, float *frame_speed, float *frame_blend, bool *frame_loop)
-{
-	*frame_range = m_animation_range;
-	*frame_speed = m_animation_speed;
-	*frame_blend = m_animation_blend;
-	*frame_loop = m_animation_loop;
-}
-
-void UnitSAO::setAnimationSpeed(float frame_speed)
-{
-	m_animation_speed = frame_speed;
-	m_animation_speed_sent = false;
-}
-
-void UnitSAO::setBonePosition(const std::string &bone, v3f position, v3f rotation)
-{
-	// store these so they can be updated to clients
-	m_bone_position[bone] = core::vector2d<v3f>(position, rotation);
-	m_bone_position_sent = false;
-}
-
-void UnitSAO::getBonePosition(const std::string &bone, v3f *position, v3f *rotation)
-{
-	*position = m_bone_position[bone].X;
-	*rotation = m_bone_position[bone].Y;
-}
-
-void UnitSAO::setAttachment(int parent_id, const std::string &bone, v3f position, v3f rotation)
-{
-	// Attachments need to be handled on both the server and client.
-	// If we just attach on the server, we can only copy the position of the parent. Attachments
-	// are still sent to clients at an interval so players might see them lagging, plus we can't
-	// read and attach to skeletal bones.
-	// If we just attach on the client, the server still sees the child at its original location.
-	// This breaks some things so we also give the server the most accurate representation
-	// even if players only see the client changes.
-
-	int old_parent = m_attachment_parent_id;
-	m_attachment_parent_id = parent_id;
-	m_attachment_bone = bone;
-	m_attachment_position = position;
-	m_attachment_rotation = rotation;
-	m_attachment_sent = false;
-
-	if (parent_id != old_parent) {
-		onDetach(old_parent);
-		onAttach(parent_id);
-	}
-}
-
-void UnitSAO::getAttachment(int *parent_id, std::string *bone, v3f *position,
-	v3f *rotation) const
-{
-	*parent_id = m_attachment_parent_id;
-	*bone = m_attachment_bone;
-	*position = m_attachment_position;
-	*rotation = m_attachment_rotation;
-}
-
-void UnitSAO::clearChildAttachments()
-{
-	for (int child_id : m_attachment_child_ids) {
-		// Child can be NULL if it was deleted earlier
-		if (ServerActiveObject *child = m_env->getActiveObject(child_id))
-			child->setAttachment(0, "", v3f(0, 0, 0), v3f(0, 0, 0));
-	}
-	m_attachment_child_ids.clear();
-}
-
-void UnitSAO::clearParentAttachment()
-{
-	ServerActiveObject *parent = nullptr;
-	if (m_attachment_parent_id) {
-		parent = m_env->getActiveObject(m_attachment_parent_id);
-		setAttachment(0, "", m_attachment_position, m_attachment_rotation);
-	} else {
-		setAttachment(0, "", v3f(0, 0, 0), v3f(0, 0, 0));
-	}
-	// Do it
-	if (parent)
-		parent->removeAttachmentChild(m_id);
-}
-
-void UnitSAO::addAttachmentChild(int child_id)
-{
-	m_attachment_child_ids.insert(child_id);
-}
-
-void UnitSAO::removeAttachmentChild(int child_id)
-{
-	m_attachment_child_ids.erase(child_id);
-}
-
-const std::unordered_set<int> &UnitSAO::getAttachmentChildIds() const
-{
-	return m_attachment_child_ids;
-}
-
-void UnitSAO::onAttach(int parent_id)
-{
-	if (!parent_id)
-		return;
-
-	ServerActiveObject *parent = m_env->getActiveObject(parent_id);
-
-	if (!parent || parent->isGone())
-		return; // Do not try to notify soon gone parent
-
-	if (parent->getType() == ACTIVEOBJECT_TYPE_LUAENTITY) {
-		// Call parent's on_attach field
-		m_env->getScriptIface()->luaentity_on_attach_child(parent_id, this);
-	}
-}
-
-void UnitSAO::onDetach(int parent_id)
-{
-	if (!parent_id)
-		return;
-
-	ServerActiveObject *parent = m_env->getActiveObject(parent_id);
-	if (getType() == ACTIVEOBJECT_TYPE_LUAENTITY)
-		m_env->getScriptIface()->luaentity_on_detach(m_id, parent);
-
-	if (!parent || parent->isGone())
-		return; // Do not try to notify soon gone parent
-
-	if (parent->getType() == ACTIVEOBJECT_TYPE_LUAENTITY)
-		m_env->getScriptIface()->luaentity_on_detach_child(parent_id, this);
-}
-
-ObjectProperties* UnitSAO::accessObjectProperties()
-{
-	return &m_prop;
-}
-
-void UnitSAO::notifyObjectPropertiesModified()
-{
-	m_properties_sent = false;
-}
-
-std::string UnitSAO::generateUpdateAttachmentCommand() const
-{
-	std::ostringstream os(std::ios::binary);
-	// command
-	writeU8(os, AO_CMD_ATTACH_TO);
-	// parameters
-	writeS16(os, m_attachment_parent_id);
-	os << serializeString(m_attachment_bone);
-	writeV3F32(os, m_attachment_position);
-	writeV3F32(os, m_attachment_rotation);
-	return os.str();
-}
-
-std::string UnitSAO::generateUpdateBonePositionCommand(const std::string &bone,
-	const v3f &position, const v3f &rotation)
-{
-	std::ostringstream os(std::ios::binary);
-	// command
-	writeU8(os, AO_CMD_SET_BONE_POSITION);
-	// parameters
-	os << serializeString(bone);
-	writeV3F32(os, position);
-	writeV3F32(os, rotation);
-	return os.str();
-}
-
-
-std::string UnitSAO::generateUpdateAnimationSpeedCommand() const
-{
-	std::ostringstream os(std::ios::binary);
-	// command
-	writeU8(os, AO_CMD_SET_ANIMATION_SPEED);
-	// parameters
-	writeF32(os, m_animation_speed);
-	return os.str();
-}
-
-std::string UnitSAO::generateUpdateAnimationCommand() const
-{
-	std::ostringstream os(std::ios::binary);
-	// command
-	writeU8(os, AO_CMD_SET_ANIMATION);
-	// parameters
-	writeV2F32(os, m_animation_range);
-	writeF32(os, m_animation_speed);
-	writeF32(os, m_animation_blend);
-	// these are sent inverted so we get true when the server sends nothing
-	writeU8(os, !m_animation_loop);
-	return os.str();
-}
-
-
-std::string UnitSAO::generateUpdateArmorGroupsCommand() const
-{
-	std::ostringstream os(std::ios::binary);
-	writeU8(os, AO_CMD_UPDATE_ARMOR_GROUPS);
-	writeU16(os, m_armor_groups.size());
-	for (const auto &armor_group : m_armor_groups) {
-		os<<serializeString(armor_group.first);
-		writeS16(os, armor_group.second);
-	}
-	return os.str();
-}
-
-
-std::string UnitSAO::generateUpdatePositionCommand(const v3f &position, const v3f &velocity,
-	const v3f &acceleration, const v3f &rotation, bool do_interpolate, bool is_movement_end,
-	f32 update_interval)
-{
-	std::ostringstream os(std::ios::binary);
-	// command
-	writeU8(os, AO_CMD_UPDATE_POSITION);
-	// pos
-	writeV3F32(os, position);
-	// velocity
-	writeV3F32(os, velocity);
-	// acceleration
-	writeV3F32(os, acceleration);
-	// rotation
-	writeV3F32(os, rotation);
-	// do_interpolate
-	writeU8(os, do_interpolate);
-	// is_end_position (for interpolation)
-	writeU8(os, is_movement_end);
-	// update_interval (for interpolation)
-	writeF32(os, update_interval);
-	return os.str();
-}
-
-
-std::string UnitSAO::generateSetPropertiesCommand(const ObjectProperties &prop) const
-{
-	std::ostringstream os(std::ios::binary);
-	writeU8(os, AO_CMD_SET_PROPERTIES);
-	prop.serialize(os);
-	return os.str();
-}
-
-std::string UnitSAO::generatePunchCommand(u16 result_hp) const
-{
-	std::ostringstream os(std::ios::binary);
-	// command
-	writeU8(os, AO_CMD_PUNCHED);
-	// result_hp
-	writeU16(os, result_hp);
-	return os.str();
-}
-
-void UnitSAO::sendPunchCommand()
-{
-	m_messages_out.emplace(getId(), true, generatePunchCommand(getHP()));
-}
-
-
-/*
 	LuaEntitySAO
 */
 
diff --git a/src/content_sao.h b/src/content_sao.h
index e0304299a..32ab922d6 100644
--- a/src/content_sao.h
+++ b/src/content_sao.h
@@ -21,100 +21,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "network/networkprotocol.h"
 #include "util/numeric.h"
-#include "serverobject.h"
+#include "server/unit_sao.h"
 #include "itemgroup.h"
-#include "object_properties.h"
 #include "constants.h"
 
-class UnitSAO: public ServerActiveObject
-{
-public:
-	UnitSAO(ServerEnvironment *env, v3f pos);
-	virtual ~UnitSAO() = default;
-
-	void setRotation(v3f rotation) { m_rotation = rotation; }
-	const v3f &getRotation() const { return m_rotation; }
-	v3f getRadRotation() { return m_rotation * core::DEGTORAD; }
-
-	// Deprecated
-	f32 getRadYawDep() const { return (m_rotation.Y + 90.) * core::DEGTORAD; }
-
-	u16 getHP() const { return m_hp; }
-	// Use a function, if isDead can be defined by other conditions
-	bool isDead() const { return m_hp == 0; }
-
-	inline bool isAttached() const
-	{ return getParent(); }
-
-	inline bool isImmortal() const
-	{ return itemgroup_get(getArmorGroups(), "immortal"); }
-
-	void setArmorGroups(const ItemGroupList &armor_groups);
-	const ItemGroupList &getArmorGroups() const;
-	void setAnimation(v2f frame_range, float frame_speed, float frame_blend, bool frame_loop);
-	void getAnimation(v2f *frame_range, float *frame_speed, float *frame_blend, bool *frame_loop);
-	void setAnimationSpeed(float frame_speed);
-	void setBonePosition(const std::string &bone, v3f position, v3f rotation);
-	void getBonePosition(const std::string &bone, v3f *position, v3f *rotation);
-	void setAttachment(int parent_id, const std::string &bone, v3f position, v3f rotation);
-	void getAttachment(int *parent_id, std::string *bone, v3f *position,
-			v3f *rotation) const;
-	void clearChildAttachments();
-	void clearParentAttachment();
-	void addAttachmentChild(int child_id);
-	void removeAttachmentChild(int child_id);
-	const std::unordered_set<int> &getAttachmentChildIds() const;
-	ServerActiveObject *getParent() const;
-	ObjectProperties* accessObjectProperties();
-	void notifyObjectPropertiesModified();
-
-	std::string generateUpdateAttachmentCommand() const;
-	std::string generateUpdateAnimationSpeedCommand() const;
-	std::string generateUpdateAnimationCommand() const;
-	std::string generateUpdateArmorGroupsCommand() const;
-	static std::string generateUpdatePositionCommand(const v3f &position, const v3f &velocity,
-			const v3f &acceleration, const v3f &rotation, bool do_interpolate,
-			bool is_movement_end, f32 update_interval);
-	std::string generateSetPropertiesCommand(const ObjectProperties &prop) const;
-	void sendPunchCommand();
-	static std::string generateUpdateBonePositionCommand(const std::string &bone,
-		const v3f &position, const v3f &rotation);
-
-protected:
-	u16 m_hp = 1;
-
-	v3f m_rotation;
-
-	bool m_properties_sent = true;
-	ObjectProperties m_prop;
-
-	ItemGroupList m_armor_groups;
-	bool m_armor_groups_sent = false;
-
-	v2f m_animation_range;
-	float m_animation_speed = 0.0f;
-	float m_animation_blend = 0.0f;
-	bool m_animation_loop = true;
-	bool m_animation_sent = false;
-	bool m_animation_speed_sent = false;
-
-	// Stores position and rotation for each bone name
-	std::unordered_map<std::string, core::vector2d<v3f>> m_bone_position;
-	bool m_bone_position_sent = false;
-
-	int m_attachment_parent_id = 0;
-	std::unordered_set<int> m_attachment_child_ids;
-	std::string m_attachment_bone = "";
-	v3f m_attachment_position;
-	v3f m_attachment_rotation;
-	bool m_attachment_sent = false;
-private:
-	void onAttach(int parent_id);
-	void onDetach(int parent_id);
-
-	std::string generatePunchCommand(u16 result_hp) const;
-};
-
 /*
 	LuaEntitySAO needs some internals exposed.
 */
diff --git a/src/emerge.cpp b/src/emerge.cpp
index 4835c3fad..fe885447c 100644
--- a/src/emerge.cpp
+++ b/src/emerge.cpp
@@ -42,7 +42,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "profiler.h"
 #include "scripting_server.h"
 #include "server.h"
-#include "serverobject.h"
 #include "settings.h"
 #include "voxel.h"
 
diff --git a/src/environment.cpp b/src/environment.cpp
index c997be3ff..6751f39e4 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -21,7 +21,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "environment.h"
 #include "collision.h"
 #include "raycast.h"
-#include "serverobject.h"
 #include "scripting_server.h"
 #include "server.h"
 #include "daynightratio.h"
diff --git a/src/inventorymanager.cpp b/src/inventorymanager.cpp
index 5a24f95a4..b6f464901 100644
--- a/src/inventorymanager.cpp
+++ b/src/inventorymanager.cpp
@@ -22,7 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "serverenvironment.h"
 #include "scripting_server.h"
-#include "serverobject.h"
+#include "server/serveractiveobject.h"
 #include "settings.h"
 #include "craftdef.h"
 #include "rollback_interface.h"
diff --git a/src/mapgen/mapgen_v6.cpp b/src/mapgen/mapgen_v6.cpp
index 8a863c044..f473f725d 100644
--- a/src/mapgen/mapgen_v6.cpp
+++ b/src/mapgen/mapgen_v6.cpp
@@ -27,7 +27,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapblock.h"
 #include "mapnode.h"
 #include "map.h"
-//#include "serverobject.h"
 #include "content_sao.h"
 #include "nodedef.h"
 #include "voxelalgorithms.h"
diff --git a/src/script/common/c_content.cpp b/src/script/common/c_content.cpp
index accbb1a87..60f12052f 100644
--- a/src/script/common/c_content.cpp
+++ b/src/script/common/c_content.cpp
@@ -29,7 +29,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "server.h"
 #include "log.h"
 #include "tool.h"
-#include "serverobject.h"
+#include "server/serveractiveobject.h"
 #include "porting.h"
 #include "mapgen/mg_schematic.h"
 #include "noise.h"
diff --git a/src/script/cpp_api/s_base.cpp b/src/script/cpp_api/s_base.cpp
index f234a15d4..16c20eeae 100644
--- a/src/script/cpp_api/s_base.cpp
+++ b/src/script/cpp_api/s_base.cpp
@@ -22,7 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "cpp_api/s_security.h"
 #include "lua_api/l_object.h"
 #include "common/c_converter.h"
-#include "serverobject.h"
+#include "server/serveractiveobject.h"
 #include "filesys.h"
 #include "content/mods.h"
 #include "porting.h"
diff --git a/src/script/lua_api/l_object.cpp b/src/script/lua_api/l_object.cpp
index 5cd978d73..1ea144a1c 100644
--- a/src/script/lua_api/l_object.cpp
+++ b/src/script/lua_api/l_object.cpp
@@ -27,7 +27,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "common/c_content.h"
 #include "log.h"
 #include "tool.h"
-#include "serverobject.h"
+#include "server/serveractiveobject.h"
 #include "content_sao.h"
 #include "remoteplayer.h"
 #include "server.h"
diff --git a/src/server.cpp b/src/server.cpp
index 062fe0798..529466f6b 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -34,7 +34,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "version.h"
 #include "filesys.h"
 #include "mapblock.h"
-#include "serverobject.h"
+#include "server/serveractiveobject.h"
 #include "settings.h"
 #include "profiler.h"
 #include "log.h"
diff --git a/src/server/CMakeLists.txt b/src/server/CMakeLists.txt
index e964c69ff..9fa5ed9fa 100644
--- a/src/server/CMakeLists.txt
+++ b/src/server/CMakeLists.txt
@@ -1,4 +1,6 @@
 set(server_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/activeobjectmgr.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/mods.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/serveractiveobject.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/unit_sao.cpp
 	PARENT_SCOPE)
diff --git a/src/server/activeobjectmgr.h b/src/server/activeobjectmgr.h
index a502ac6ed..5fea1bea6 100644
--- a/src/server/activeobjectmgr.h
+++ b/src/server/activeobjectmgr.h
@@ -22,7 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <functional>
 #include <vector>
 #include "../activeobjectmgr.h"
-#include "serverobject.h"
+#include "serveractiveobject.h"
 
 namespace server
 {
diff --git a/src/serverobject.cpp b/src/server/serveractiveobject.cpp
index 119a41b7b..3aa78c7d5 100644
--- a/src/serverobject.cpp
+++ b/src/server/serveractiveobject.cpp
@@ -17,7 +17,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
-#include "serverobject.h"
+#include "serveractiveobject.h"
 #include <fstream>
 #include "inventory.h"
 #include "constants.h" // BS
diff --git a/src/serverobject.h b/src/server/serveractiveobject.h
index 2e013a6b6..2e013a6b6 100644
--- a/src/serverobject.h
+++ b/src/server/serveractiveobject.h
diff --git a/src/server/unit_sao.cpp b/src/server/unit_sao.cpp
new file mode 100644
index 000000000..66be67522
--- /dev/null
+++ b/src/server/unit_sao.cpp
@@ -0,0 +1,318 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+Copyright (C) 2013-2020 Minetest core developers & community
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "unit_sao.h"
+#include "scripting_server.h"
+#include "serverenvironment.h"
+
+/*
+	UnitSAO
+ */
+
+UnitSAO::UnitSAO(ServerEnvironment *env, v3f pos):
+	ServerActiveObject(env, pos)
+{
+	// Initialize something to armor groups
+	m_armor_groups["fleshy"] = 100;
+}
+
+ServerActiveObject *UnitSAO::getParent() const
+{
+	if (!m_attachment_parent_id)
+		return nullptr;
+	// Check if the parent still exists
+	ServerActiveObject *obj = m_env->getActiveObject(m_attachment_parent_id);
+
+	return obj;
+}
+
+void UnitSAO::setArmorGroups(const ItemGroupList &armor_groups)
+{
+	m_armor_groups = armor_groups;
+	m_armor_groups_sent = false;
+}
+
+const ItemGroupList &UnitSAO::getArmorGroups() const
+{
+	return m_armor_groups;
+}
+
+void UnitSAO::setAnimation(v2f frame_range, float frame_speed, float frame_blend, bool frame_loop)
+{
+	// store these so they can be updated to clients
+	m_animation_range = frame_range;
+	m_animation_speed = frame_speed;
+	m_animation_blend = frame_blend;
+	m_animation_loop = frame_loop;
+	m_animation_sent = false;
+}
+
+void UnitSAO::getAnimation(v2f *frame_range, float *frame_speed, float *frame_blend, bool *frame_loop)
+{
+	*frame_range = m_animation_range;
+	*frame_speed = m_animation_speed;
+	*frame_blend = m_animation_blend;
+	*frame_loop = m_animation_loop;
+}
+
+void UnitSAO::setAnimationSpeed(float frame_speed)
+{
+	m_animation_speed = frame_speed;
+	m_animation_speed_sent = false;
+}
+
+void UnitSAO::setBonePosition(const std::string &bone, v3f position, v3f rotation)
+{
+	// store these so they can be updated to clients
+	m_bone_position[bone] = core::vector2d<v3f>(position, rotation);
+	m_bone_position_sent = false;
+}
+
+void UnitSAO::getBonePosition(const std::string &bone, v3f *position, v3f *rotation)
+{
+	*position = m_bone_position[bone].X;
+	*rotation = m_bone_position[bone].Y;
+}
+
+void UnitSAO::setAttachment(int parent_id, const std::string &bone, v3f position, v3f rotation)
+{
+	// Attachments need to be handled on both the server and client.
+	// If we just attach on the server, we can only copy the position of the parent. Attachments
+	// are still sent to clients at an interval so players might see them lagging, plus we can't
+	// read and attach to skeletal bones.
+	// If we just attach on the client, the server still sees the child at its original location.
+	// This breaks some things so we also give the server the most accurate representation
+	// even if players only see the client changes.
+
+	int old_parent = m_attachment_parent_id;
+	m_attachment_parent_id = parent_id;
+	m_attachment_bone = bone;
+	m_attachment_position = position;
+	m_attachment_rotation = rotation;
+	m_attachment_sent = false;
+
+	if (parent_id != old_parent) {
+		onDetach(old_parent);
+		onAttach(parent_id);
+	}
+}
+
+void UnitSAO::getAttachment(int *parent_id, std::string *bone, v3f *position,
+	v3f *rotation) const
+{
+	*parent_id = m_attachment_parent_id;
+	*bone = m_attachment_bone;
+	*position = m_attachment_position;
+	*rotation = m_attachment_rotation;
+}
+
+void UnitSAO::clearChildAttachments()
+{
+	for (int child_id : m_attachment_child_ids) {
+		// Child can be NULL if it was deleted earlier
+		if (ServerActiveObject *child = m_env->getActiveObject(child_id))
+			child->setAttachment(0, "", v3f(0, 0, 0), v3f(0, 0, 0));
+	}
+	m_attachment_child_ids.clear();
+}
+
+void UnitSAO::clearParentAttachment()
+{
+	ServerActiveObject *parent = nullptr;
+	if (m_attachment_parent_id) {
+		parent = m_env->getActiveObject(m_attachment_parent_id);
+		setAttachment(0, "", m_attachment_position, m_attachment_rotation);
+	} else {
+		setAttachment(0, "", v3f(0, 0, 0), v3f(0, 0, 0));
+	}
+	// Do it
+	if (parent)
+		parent->removeAttachmentChild(m_id);
+}
+
+void UnitSAO::addAttachmentChild(int child_id)
+{
+	m_attachment_child_ids.insert(child_id);
+}
+
+void UnitSAO::removeAttachmentChild(int child_id)
+{
+	m_attachment_child_ids.erase(child_id);
+}
+
+const std::unordered_set<int> &UnitSAO::getAttachmentChildIds() const
+{
+	return m_attachment_child_ids;
+}
+
+void UnitSAO::onAttach(int parent_id)
+{
+	if (!parent_id)
+		return;
+
+	ServerActiveObject *parent = m_env->getActiveObject(parent_id);
+
+	if (!parent || parent->isGone())
+		return; // Do not try to notify soon gone parent
+
+	if (parent->getType() == ACTIVEOBJECT_TYPE_LUAENTITY) {
+		// Call parent's on_attach field
+		m_env->getScriptIface()->luaentity_on_attach_child(parent_id, this);
+	}
+}
+
+void UnitSAO::onDetach(int parent_id)
+{
+	if (!parent_id)
+		return;
+
+	ServerActiveObject *parent = m_env->getActiveObject(parent_id);
+	if (getType() == ACTIVEOBJECT_TYPE_LUAENTITY)
+		m_env->getScriptIface()->luaentity_on_detach(m_id, parent);
+
+	if (!parent || parent->isGone())
+		return; // Do not try to notify soon gone parent
+
+	if (parent->getType() == ACTIVEOBJECT_TYPE_LUAENTITY)
+		m_env->getScriptIface()->luaentity_on_detach_child(parent_id, this);
+}
+
+ObjectProperties* UnitSAO::accessObjectProperties()
+{
+	return &m_prop;
+}
+
+void UnitSAO::notifyObjectPropertiesModified()
+{
+	m_properties_sent = false;
+}
+
+std::string UnitSAO::generateUpdateAttachmentCommand() const
+{
+	std::ostringstream os(std::ios::binary);
+	// command
+	writeU8(os, AO_CMD_ATTACH_TO);
+	// parameters
+	writeS16(os, m_attachment_parent_id);
+	os << serializeString(m_attachment_bone);
+	writeV3F32(os, m_attachment_position);
+	writeV3F32(os, m_attachment_rotation);
+	return os.str();
+}
+
+std::string UnitSAO::generateUpdateBonePositionCommand(const std::string &bone,
+	const v3f &position, const v3f &rotation)
+{
+	std::ostringstream os(std::ios::binary);
+	// command
+	writeU8(os, AO_CMD_SET_BONE_POSITION);
+	// parameters
+	os << serializeString(bone);
+	writeV3F32(os, position);
+	writeV3F32(os, rotation);
+	return os.str();
+}
+
+
+std::string UnitSAO::generateUpdateAnimationSpeedCommand() const
+{
+	std::ostringstream os(std::ios::binary);
+	// command
+	writeU8(os, AO_CMD_SET_ANIMATION_SPEED);
+	// parameters
+	writeF32(os, m_animation_speed);
+	return os.str();
+}
+
+std::string UnitSAO::generateUpdateAnimationCommand() const
+{
+	std::ostringstream os(std::ios::binary);
+	// command
+	writeU8(os, AO_CMD_SET_ANIMATION);
+	// parameters
+	writeV2F32(os, m_animation_range);
+	writeF32(os, m_animation_speed);
+	writeF32(os, m_animation_blend);
+	// these are sent inverted so we get true when the server sends nothing
+	writeU8(os, !m_animation_loop);
+	return os.str();
+}
+
+
+std::string UnitSAO::generateUpdateArmorGroupsCommand() const
+{
+	std::ostringstream os(std::ios::binary);
+	writeU8(os, AO_CMD_UPDATE_ARMOR_GROUPS);
+	writeU16(os, m_armor_groups.size());
+	for (const auto &armor_group : m_armor_groups) {
+		os<<serializeString(armor_group.first);
+		writeS16(os, armor_group.second);
+	}
+	return os.str();
+}
+
+
+std::string UnitSAO::generateUpdatePositionCommand(const v3f &position, const v3f &velocity,
+	const v3f &acceleration, const v3f &rotation, bool do_interpolate, bool is_movement_end,
+	f32 update_interval)
+{
+	std::ostringstream os(std::ios::binary);
+	// command
+	writeU8(os, AO_CMD_UPDATE_POSITION);
+	// pos
+	writeV3F32(os, position);
+	// velocity
+	writeV3F32(os, velocity);
+	// acceleration
+	writeV3F32(os, acceleration);
+	// rotation
+	writeV3F32(os, rotation);
+	// do_interpolate
+	writeU8(os, do_interpolate);
+	// is_end_position (for interpolation)
+	writeU8(os, is_movement_end);
+	// update_interval (for interpolation)
+	writeF32(os, update_interval);
+	return os.str();
+}
+
+
+std::string UnitSAO::generateSetPropertiesCommand(const ObjectProperties &prop) const
+{
+	std::ostringstream os(std::ios::binary);
+	writeU8(os, AO_CMD_SET_PROPERTIES);
+	prop.serialize(os);
+	return os.str();
+}
+
+std::string UnitSAO::generatePunchCommand(u16 result_hp) const
+{
+	std::ostringstream os(std::ios::binary);
+	// command
+	writeU8(os, AO_CMD_PUNCHED);
+	// result_hp
+	writeU16(os, result_hp);
+	return os.str();
+}
+
+void UnitSAO::sendPunchCommand()
+{
+	m_messages_out.emplace(getId(), true, generatePunchCommand(getHP()));
+}
diff --git a/src/server/unit_sao.h b/src/server/unit_sao.h
new file mode 100644
index 000000000..d0e20fb77
--- /dev/null
+++ b/src/server/unit_sao.h
@@ -0,0 +1,113 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+Copyright (C) 2013-2020 Minetest core developers & community
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "object_properties.h"
+#include "serveractiveobject.h"
+
+class UnitSAO: public ServerActiveObject
+{
+public:
+	UnitSAO(ServerEnvironment *env, v3f pos);
+	virtual ~UnitSAO() = default;
+
+	void setRotation(v3f rotation) { m_rotation = rotation; }
+	const v3f &getRotation() const { return m_rotation; }
+	v3f getRadRotation() { return m_rotation * core::DEGTORAD; }
+
+	// Deprecated
+	f32 getRadYawDep() const { return (m_rotation.Y + 90.) * core::DEGTORAD; }
+
+	u16 getHP() const { return m_hp; }
+	// Use a function, if isDead can be defined by other conditions
+	bool isDead() const { return m_hp == 0; }
+
+	inline bool isAttached() const
+	{ return getParent(); }
+
+	inline bool isImmortal() const
+	{ return itemgroup_get(getArmorGroups(), "immortal"); }
+
+	void setArmorGroups(const ItemGroupList &armor_groups);
+	const ItemGroupList &getArmorGroups() const;
+	void setAnimation(v2f frame_range, float frame_speed, float frame_blend, bool frame_loop);
+	void getAnimation(v2f *frame_range, float *frame_speed, float *frame_blend, bool *frame_loop);
+	void setAnimationSpeed(float frame_speed);
+	void setBonePosition(const std::string &bone, v3f position, v3f rotation);
+	void getBonePosition(const std::string &bone, v3f *position, v3f *rotation);
+	void setAttachment(int parent_id, const std::string &bone, v3f position, v3f rotation);
+	void getAttachment(int *parent_id, std::string *bone, v3f *position,
+			v3f *rotation) const;
+	void clearChildAttachments();
+	void clearParentAttachment();
+	void addAttachmentChild(int child_id);
+	void removeAttachmentChild(int child_id);
+	const std::unordered_set<int> &getAttachmentChildIds() const;
+	ServerActiveObject *getParent() const;
+	ObjectProperties* accessObjectProperties();
+	void notifyObjectPropertiesModified();
+
+	std::string generateUpdateAttachmentCommand() const;
+	std::string generateUpdateAnimationSpeedCommand() const;
+	std::string generateUpdateAnimationCommand() const;
+	std::string generateUpdateArmorGroupsCommand() const;
+	static std::string generateUpdatePositionCommand(const v3f &position, const v3f &velocity,
+			const v3f &acceleration, const v3f &rotation, bool do_interpolate,
+			bool is_movement_end, f32 update_interval);
+	std::string generateSetPropertiesCommand(const ObjectProperties &prop) const;
+	void sendPunchCommand();
+	static std::string generateUpdateBonePositionCommand(const std::string &bone,
+		const v3f &position, const v3f &rotation);
+
+protected:
+	u16 m_hp = 1;
+
+	v3f m_rotation;
+
+	bool m_properties_sent = true;
+	ObjectProperties m_prop;
+
+	ItemGroupList m_armor_groups;
+	bool m_armor_groups_sent = false;
+
+	v2f m_animation_range;
+	float m_animation_speed = 0.0f;
+	float m_animation_blend = 0.0f;
+	bool m_animation_loop = true;
+	bool m_animation_sent = false;
+	bool m_animation_speed_sent = false;
+
+	// Stores position and rotation for each bone name
+	std::unordered_map<std::string, core::vector2d<v3f>> m_bone_position;
+	bool m_bone_position_sent = false;
+
+	int m_attachment_parent_id = 0;
+	std::unordered_set<int> m_attachment_child_ids;
+	std::string m_attachment_bone = "";
+	v3f m_attachment_position;
+	v3f m_attachment_rotation;
+	bool m_attachment_sent = false;
+private:
+	void onAttach(int parent_id);
+	void onDetach(int parent_id);
+
+	std::string generatePunchCommand(u16 result_hp) const;
+};