+ qbyte colormap;
+ qbyte skin;
+ qbyte alpha;
+ qbyte scale;
+ qbyte glowsize;
+ qbyte glowcolor;
+ qbyte flags;
+}
+entity_state_t;
+
+/*
+DPPROTOCOL_VERSION3
+server updates entities according to some (unmentioned) scheme.
+
+a frame consists of all visible entities, some of which are up to date,
+often some are not up to date.
+
+these entities are stored in a range (firstentity/endentity) of structs in the
+entitydata[] buffer.
+
+to make a commit the server performs these steps:
+1. duplicate oldest frame in database (this is the baseline) as new frame, and
+ write frame numbers (oldest frame's number, new frame's number) and eye
+ location to network packet (eye location is obsolete and will be removed in
+ future revisions)
+2. write an entity change to packet and modify new frame accordingly
+ (this repeats until packet is sufficiently full or new frame is complete)
+3. write terminator (0xFFFF) to network packet
+ (FIXME: this terminator value conflicts with MAX_EDICTS 32768...)
+
+to read a commit the client performs these steps:
+1. reads frame numbers from packet and duplicates baseline frame as new frame,
+ also reads eye location but does nothing with it (obsolete).
+2. delete frames older than the baseline which was used
+3. read entity changes from packet until terminator (0xFFFF) is encountered,
+ each change is applied to entity frame.
+4. sends ack framenumber to server as part of input packet
+
+if server receives ack message in put packet it performs these steps:
+1. remove all older frames from database.
+*/
+
+typedef struct
+{
+ double time;
+ int framenum;
+ int firstentity; // index into entitydata, modulo MAX_ENTITY_DATABASE
+ int endentity; // index into entitydata, firstentity + numentities
+}
+entity_frameinfo_t;
+
+#define MAX_ENTITY_HISTORY 64
+#define MAX_ENTITY_DATABASE (MAX_EDICTS * 2)
+
+typedef struct
+{
+ // note: these can be far out of range, modulo with MAX_ENTITY_DATABASE to get a valid range (which may wrap)
+ // start and end of used area, when adding a new update to database, store at endpos, and increment endpos
+ // when removing updates from database, nudge down frames array to only contain useful frames
+ // this logic should explain better:
+ // if (numframes >= MAX_ENTITY_HISTORY || (frames[numframes - 1].endentity - frames[0].firstentity) + entitiestoadd > MAX_ENTITY_DATABASE)
+ // flushdatabase();
+ // note: if numframes == 0, insert at start (0 in entitydata)
+ // the only reason this system is used is to avoid copying memory when frames are removed
+ int numframes;
+ // server only: last acknowledged frame
+ int ackframe;
+ // the current state in the database
+ vec3_t eye;
+ // table of entities in the entityhistorydata
+ entity_frameinfo_t frames[MAX_ENTITY_HISTORY];
+ // entities
+ entity_state_t entitydata[MAX_ENTITY_DATABASE];
+}
+entity_database_t;
+
+// build entity data in this, to pass to entity read/write functions
+typedef struct
+{
+ double time;
+ int framenum;
+ int numentities;
+ vec3_t eye;
+ entity_state_t entitydata[MAX_ENTITY_DATABASE];
+}
+entity_frame_t;
+
+// LordHavoc: these are in approximately sorted order, according to cost and
+// likelyhood of being used for numerous objects in a frame
+
+// note that the bytes are not written/read in this order, this is only the
+// order of the bits to minimize overhead from extend bytes
+
+// enough to describe a nail, gib, shell casing, bullet hole, or rocket
+#define E_ORIGIN1 (1<<0)
+#define E_ORIGIN2 (1<<1)
+#define E_ORIGIN3 (1<<2)
+#define E_ANGLE1 (1<<3)
+#define E_ANGLE2 (1<<4)
+#define E_ANGLE3 (1<<5)
+#define E_MODEL1 (1<<6)
+#define E_EXTEND1 (1<<7)
+
+// enough to describe almost anything
+#define E_FRAME1 (1<<8)
+#define E_EFFECTS1 (1<<9)
+#define E_ALPHA (1<<10)
+#define E_SCALE (1<<11)
+#define E_COLORMAP (1<<12)
+#define E_SKIN (1<<13)
+#define E_FLAGS (1<<14)
+#define E_EXTEND2 (1<<15)
+
+// players, custom color glows, high model numbers
+#define E_FRAME2 (1<<16)
+#define E_MODEL2 (1<<17)
+#define E_EFFECTS2 (1<<18)
+#define E_GLOWSIZE (1<<19)
+#define E_GLOWCOLOR (1<<20)
+#define E_UNUSED1 (1<<21)
+#define E_UNUSED2 (1<<22)
+#define E_EXTEND3 (1<<23)
+
+#define E_SOUND1 (1<<24)
+#define E_SOUNDVOL (1<<25)
+#define E_SOUNDATTEN (1<<26)
+#define E_UNUSED4 (1<<27)
+#define E_UNUSED5 (1<<28)
+#define E_UNUSED6 (1<<29)
+#define E_UNUSED7 (1<<30)
+#define E_EXTEND4 (1<<31)