Add support for limiting rotation of automatic face movement dir entitys

src/content_cao.cpp

@@ -1260,8 +1260,18 @@ void GenericCAO::step(float dtime, ClientEnvironment *env)
 	if (getParent() == NULL && m_prop.automatic_face_movement_dir &&
 			(fabs(m_velocity.Z) > 0.001 || fabs(m_velocity.X) > 0.001))
 	{
-		m_yaw = atan2(m_velocity.Z,m_velocity.X) * 180 / M_PI
+		float optimal_yaw = atan2(m_velocity.Z,m_velocity.X) * 180 / M_PI
 				+ m_prop.automatic_face_movement_dir_offset;
+		float max_rotation_delta =
+				dtime * m_prop.automatic_face_movement_max_rotation_per_sec;
+
+		if ((m_prop.automatic_face_movement_max_rotation_per_sec > 0) &&
+			(fabs(m_yaw - optimal_yaw) > max_rotation_delta)) {
+
+			m_yaw = optimal_yaw < m_yaw ? m_yaw - max_rotation_delta : m_yaw + max_rotation_delta;
+		} else {
+			m_yaw = optimal_yaw;
+		}
 		updateNodePos();
 	}
 }

src/content_sao.cpp

@@ -283,8 +283,20 @@ void LuaEntitySAO::step(float dtime, bool send_recommended)
 		}
 
 		if((m_prop.automatic_face_movement_dir) &&
-				(fabs(m_velocity.Z) > 0.001 || fabs(m_velocity.X) > 0.001)){
-			m_yaw = atan2(m_velocity.Z,m_velocity.X) * 180 / M_PI + m_prop.automatic_face_movement_dir_offset;
+				(fabs(m_velocity.Z) > 0.001 || fabs(m_velocity.X) > 0.001))
+		{
+			float optimal_yaw = atan2(m_velocity.Z,m_velocity.X) * 180 / M_PI
+					+ m_prop.automatic_face_movement_dir_offset;
+			float max_rotation_delta =
+					dtime * m_prop.automatic_face_movement_max_rotation_per_sec;
+
+			if ((m_prop.automatic_face_movement_max_rotation_per_sec > 0) &&
+				(fabs(m_yaw - optimal_yaw) > max_rotation_delta)) {
+
+				m_yaw = optimal_yaw < m_yaw ? m_yaw - max_rotation_delta : m_yaw + max_rotation_delta;
+			} else {
+				m_yaw = optimal_yaw;
+			}
 		}
 	}
 

src/object_properties.cpp

@@ -45,7 +45,8 @@ ObjectProperties::ObjectProperties():
 	automatic_face_movement_dir_offset(0.0),
 	backface_culling(true),
 	nametag(""),
-	nametag_color(255, 255, 255, 255)
+	nametag_color(255, 255, 255, 255),
+	automatic_face_movement_max_rotation_per_sec(-1)
 {
 	textures.push_back("unknown_object.png");
 	colors.push_back(video::SColor(255,255,255,255));
@@ -116,6 +117,8 @@ void ObjectProperties::serialize(std::ostream &os) const
 	writeU8(os, backface_culling);
 	os << serializeString(nametag);
 	writeARGB8(os, nametag_color);
+	writeF1000(os, automatic_face_movement_max_rotation_per_sec);
+
 	// Add stuff only at the bottom.
 	// Never remove anything, because we don't want new versions of this
 }
@@ -155,6 +158,7 @@ void ObjectProperties::deSerialize(std::istream &is)
 			backface_culling = readU8(is);
 			nametag = deSerializeString(is);
 			nametag_color = readARGB8(is);
+			automatic_face_movement_max_rotation_per_sec = readF1000(is);
 		}catch(SerializationError &e){}
 	}
 	else

src/object_properties.h

@@ -50,7 +50,7 @@ struct ObjectProperties
 	bool backface_culling;
 	std::string nametag;
 	video::SColor nametag_color;
-
+	f32 automatic_face_movement_max_rotation_per_sec;
 
 	ObjectProperties();
 	std::string dump();

src/script/common/c_content.cpp

@@ -201,6 +201,7 @@ void read_object_properties(lua_State *L, int index,
 	}
 	lua_pop(L, 1);
 	getboolfield(L, -1, "backface_culling", prop->backface_culling);
+
 	getstringfield(L, -1, "nametag", prop->nametag);
 	lua_getfield(L, -1, "nametag_color");
 	if (!lua_isnil(L, -1)) {
@@ -208,6 +209,11 @@ void read_object_properties(lua_State *L, int index,
 		if (read_color(L, -1, &color))
 			prop->nametag_color = color;
 	}
+
+	lua_getfield(L, -1, "automatic_face_movement_max_rotation_per_sec");
+	if (lua_isnumber(L, -1)) {
+		prop->automatic_face_movement_max_rotation_per_sec = luaL_checknumber(L, -1);
+	}
 	lua_pop(L, 1);
 }