From fc571ad46df8f3dcc04745bc55d9ca6e1e82ed87 Mon Sep 17 00:00:00 2001
From: sapier <Sapier at GMX dot net>
Date: Wed, 31 Jul 2013 17:29:25 +0200
Subject: [PATCH] Add support for entities to automatic face movement direction

---
 doc/lua_api.txt                 | 1 +
 src/clientserver.h              | 1 +
 src/content_cao.cpp             | 5 +++++
 src/content_sao.cpp             | 5 +++++
 src/object_properties.cpp       | 5 ++++-
 src/object_properties.h         | 1 +
 src/script/common/c_content.cpp | 1 +
 7 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 3dfb67157..5244ff221 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1863,6 +1863,7 @@ Object Properties
     makes_footstep_sound = false,
     automatic_rotate = false,
     stepheight = 0,
+    automatic_face_movement_dir = false,
 }
 
 Entity definition (register_entity)
diff --git a/src/clientserver.h b/src/clientserver.h
index 264da5179..ebfe7f3c7 100644
--- a/src/clientserver.h
+++ b/src/clientserver.h
@@ -102,6 +102,7 @@ SharedBuffer<u8> makePacket_TOCLIENT_TIME_OF_DAY(u16 time, float time_speed);
 		drowning, leveled and liquid_range added to ContentFeatures
 		stepheight and collideWithObjects added to object properties
 		version, heat and humidity transfer in MapBock
+		added new property to entities automatic_face_movement_dir
 */
 
 #define LATEST_PROTOCOL_VERSION 21
diff --git a/src/content_cao.cpp b/src/content_cao.cpp
index bbee0bc83..20f5fd3db 100644
--- a/src/content_cao.cpp
+++ b/src/content_cao.cpp
@@ -1210,6 +1210,11 @@ public:
 			m_yaw += dtime * m_prop.automatic_rotate * 180 / M_PI;
 			updateNodePos();
 		}
+
+		if (getParent() == NULL && m_prop.automatic_face_movement_dir){
+			m_yaw = atan2(m_velocity.Z,m_velocity.X) * 180 / M_PI;
+			updateNodePos();
+		}
 	}
 
 	void updateTexturePos()
diff --git a/src/content_sao.cpp b/src/content_sao.cpp
index ed660cf10..f3ccd6db0 100644
--- a/src/content_sao.cpp
+++ b/src/content_sao.cpp
@@ -30,6 +30,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "cpp_api/scriptapi.h"
 #include "genericobject.h"
 #include "util/serialize.h"
+#include "util/mathconstants.h"
 
 std::map<u16, ServerActiveObject::Factory> ServerActiveObject::m_types;
 
@@ -522,6 +523,10 @@ void LuaEntitySAO::step(float dtime, bool send_recommended)
 					* dtime * m_acceleration;
 			m_velocity += dtime * m_acceleration;
 		}
+
+		if(m_prop.automatic_face_movement_dir){
+			m_yaw = atan2(m_velocity.Z,m_velocity.X) * 180 / M_PI;
+		}
 	}
 
 	if(m_registered){
diff --git a/src/object_properties.cpp b/src/object_properties.cpp
index 1602f03f2..7fad25cce 100644
--- a/src/object_properties.cpp
+++ b/src/object_properties.cpp
@@ -40,7 +40,8 @@ ObjectProperties::ObjectProperties():
 	is_visible(true),
 	makes_footstep_sound(false),
 	automatic_rotate(0),
-	stepheight(0)
+	stepheight(0),
+	automatic_face_movement_dir(false)
 {
 	textures.push_back("unknown_object.png");
 	colors.push_back(video::SColor(255,255,255,255));
@@ -102,6 +103,7 @@ void ObjectProperties::serialize(std::ostream &os) const
 	}
 	writeU8(os, collideWithObjects);
 	writeF1000(os,stepheight);
+	writeU8(os, automatic_face_movement_dir);
 	// Add stuff only at the bottom.
 	// Never remove anything, because we don't want new versions of this
 }
@@ -136,6 +138,7 @@ void ObjectProperties::deSerialize(std::istream &is)
 			}
 			collideWithObjects = readU8(is);
 			stepheight = readF1000(is);
+			automatic_face_movement_dir = readU8(is);
 		}catch(SerializationError &e){}
 	}
 	else
diff --git a/src/object_properties.h b/src/object_properties.h
index e8188cb60..edc9c39d6 100644
--- a/src/object_properties.h
+++ b/src/object_properties.h
@@ -45,6 +45,7 @@ struct ObjectProperties
 	bool makes_footstep_sound;
 	float automatic_rotate;
 	f32 stepheight;
+	bool automatic_face_movement_dir;
 
 
 	ObjectProperties();
diff --git a/src/script/common/c_content.cpp b/src/script/common/c_content.cpp
index ca7c7fde9..cb2b0e737 100644
--- a/src/script/common/c_content.cpp
+++ b/src/script/common/c_content.cpp
@@ -190,6 +190,7 @@ void read_object_properties(lua_State *L, int index,
 	getfloatfield(L, -1, "automatic_rotate", prop->automatic_rotate);
 	getfloatfield(L, -1, "stepheight", prop->stepheight);
 	prop->stepheight*=BS;
+	getboolfield(L, -1, "automatic_face_movement_dir", prop->automatic_face_movement_dir);
 }
 
 /******************************************************************************/