1 // mpmessages.hxx -- Message definitions for multiplayer communications
2 // within a multiplayer Flightgear
4 // Written by Duncan McCreanor, started February 2003.
5 // duncan.mccreanor@airservicesaustralia.com
7 // Copyright (C) 2003 Airservices Australia
9 // This program is free software; you can redistribute it and/or
10 // modify it under the terms of the GNU General Public License as
11 // published by the Free Software Foundation; either version 2 of the
12 // License, or (at your option) any later version.
14 // This program is distributed in the hope that it will be useful, but
15 // WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 // General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
27 #define MPMESSAGES_HID "$Id$"
29 /****************************************************************
32 * Description: Each message used for multiplayer communications
33 * consists of a header and optionally a block of data. The combined
34 * header and data is sent as one IP packet.
36 ******************************************************************/
41 #include <simgear/compiler.h>
42 #include <simgear/props/props.hxx>
43 #include <simgear/math/SGMath.hxx>
44 #include "tiny_xdr.hxx"
46 // magic value for messages
47 const uint32_t MSG_MAGIC = 0x46474653; // "FGFS"
49 const uint32_t PROTO_VER = 0x00010001; // 1.1
51 // Message identifiers
53 #define UNUSABLE_POS_DATA_ID 2
54 #define OLD_OLD_POS_DATA_ID 3
55 #define OLD_POS_DATA_ID 4
56 #define OLD_PROP_MSG_ID 5
57 #define RESET_DATA_ID 6
60 // XDR demands 4 byte alignment, but some compilers use8 byte alignment
61 // so it's safe to let the overall size of a network message be a
63 #define MAX_CALLSIGN_LEN 8
64 #define MAX_CHAT_MSG_LEN 256
65 #define MAX_MODEL_NAME_LEN 96
66 #define MAX_PROPERTY_LEN 52
68 // Header for use with all messages sent
70 xdr_data_t Magic; // Magic Value
71 xdr_data_t Version; // Protocoll version
72 xdr_data_t MsgId; // Message identifier
73 xdr_data_t MsgLen; // absolute length of message
74 xdr_data_t ReplyAddress; // (player's receiver address
75 xdr_data_t ReplyPort; // player's receiver port
76 char Callsign[MAX_CALLSIGN_LEN]; // Callsign used by the player
81 char Text[MAX_CHAT_MSG_LEN]; // Text of chat message
85 struct T_PositionMsg {
86 char Model[MAX_MODEL_NAME_LEN]; // Name of the aircraft model
88 // Time when this packet was generated
92 // position wrt the earth centered frame
93 xdr_data2_t position[3];
94 // orientation wrt the earth centered frame, stored in the angle axis
95 // representation where the angle is coded into the axis length
96 xdr_data_t orientation[3];
98 // linear velocity wrt the earth centered frame measured in
99 // the earth centered frame
100 xdr_data_t linearVel[3];
101 // angular velocity wrt the earth centered frame measured in
102 // the earth centered frame
103 xdr_data_t angularVel[3];
105 // linear acceleration wrt the earth centered frame measured in
106 // the earth centered frame
107 xdr_data_t linearAccel[3];
108 // angular acceleration wrt the earth centered frame measured in
109 // the earth centered frame
110 xdr_data_t angularAccel[3];
111 // Padding. The alignment is 8 bytes on x86_64 because there are
112 // 8-byte types in the message, so the size should be explicitly
113 // rounded out to a multiple of 8. Of course, it's a bad idea to
114 // put a C struct directly on the wire, but that's a fight for
119 struct FGPropertyData {
122 // While the type isn't transmitted, it is needed for the destructor
123 SGPropertyNode::Type type;
131 if ((type == SGPropertyNode::STRING) || (type == SGPropertyNode::UNSPECIFIED))
133 delete [] string_value;
141 struct FGExternalMotionData {
142 // simulation time when this packet was generated
144 // the artificial lag the client should stay behind the average
145 // simulation time to arrival time diference
146 // FIXME: should be some 'per model' instead of 'per packet' property
149 // position wrt the earth centered frame
151 // orientation wrt the earth centered frame
154 // linear velocity wrt the earth centered frame measured in
155 // the earth centered frame
157 // angular velocity wrt the earth centered frame measured in
158 // the earth centered frame
161 // linear acceleration wrt the earth centered frame measured in
162 // the earth centered frame
164 // angular acceleration wrt the earth centered frame measured in
165 // the earth centered frame
166 SGVec3f angularAccel;
168 // The set of properties recieved for this timeslot
169 std::vector<FGPropertyData*> properties;