/*
Copyright (C) 1996-1997 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// protocol.h -- communications protocols

#ifndef PROTOCOL_H
#define PROTOCOL_H

// protocolversion_t is defined in common.h

protocolversion_t Protocol_EnumForName(const char *s);
const char *Protocol_NameForEnum(protocolversion_t p);
protocolversion_t Protocol_EnumForNumber(int n);
int Protocol_NumberForEnum(protocolversion_t p);
void Protocol_Names(char *buffer, size_t buffersize);

// model effects
#define	MF_ROCKET	1			// leave a trail
#define	MF_GRENADE	2			// leave a trail
#define	MF_GIB		4			// leave a trail
#define	MF_ROTATE	8			// rotate (bonus items)
#define	MF_TRACER	16			// green split trail
#define	MF_ZOMGIB	32			// small blood trail
#define	MF_TRACER2	64			// orange split trail + rotate
#define	MF_TRACER3	128			// purple trail

// entity effects
#define	EF_BRIGHTFIELD			1
#define	EF_MUZZLEFLASH 			2
#define	EF_BRIGHTLIGHT 			4
#define	EF_DIMLIGHT 			8
#define	EF_NODRAW				16
#define EF_ADDITIVE				32
#define EF_BLUE					64
#define EF_RED					128
#define EF_NOGUNBOB				256			// LordHavoc: when used with .viewmodelforclient this makes the entity attach to the view without gun bobbing and such effects, it also works on the player entity to disable gun bobbing of the engine-managed .viewmodel (without affecting any .viewmodelforclient entities attached to the player)
#define EF_FULLBRIGHT			512			// LordHavoc: fullbright
#define EF_FLAME				1024		// LordHavoc: on fire
#define EF_STARDUST				2048		// LordHavoc: showering sparks
#define EF_NOSHADOW				4096		// LordHavoc: does not cast a shadow
#define EF_NODEPTHTEST			8192		// LordHavoc: shows through walls
#define EF_SELECTABLE			16384		// LordHavoc: highlights when PRYDON_CLIENTCURSOR mouse is over it
#define EF_DOUBLESIDED			32768		//[515]: disable cull face for this entity
#define EF_NOSELFSHADOW			65536		// LordHavoc: does not cast a shadow on itself (or any other EF_NOSELFSHADOW entities)
#define EF_DYNAMICMODELLIGHT			131072
#define EF_UNUSED18				262144
#define EF_UNUSED19				524288
#define EF_RESTARTANIM_BIT		1048576     // div0: restart animation bit (like teleport bit, but lerps between end and start of the anim, and doesn't stop player lerping)
#define EF_TELEPORT_BIT			2097152		// div0: teleport bit (toggled when teleporting, prevents lerping when the bit has changed)
#define EF_LOWPRECISION			4194304		// LordHavoc: entity is low precision (integer coordinates) to save network bandwidth  (serverside only)
#define EF_NOMODELFLAGS			8388608		// indicates the model's .effects should be ignored (allows overriding them)
#define EF_ROCKET				16777216	// leave a trail
#define EF_GRENADE				33554432	// leave a trail
#define EF_GIB					67108864	// leave a trail
#define EF_ROTATE				134217728	// rotate (bonus items)
#define EF_TRACER				268435456	// green split trail
#define EF_ZOMGIB				536870912	// small blood trail
#define EF_TRACER2				1073741824	// orange split trail + rotate
#define EF_TRACER3				0x80000000	// purple trail

// internaleffects bits (no overlap with EF_ bits):
#define INTEF_FLAG1QW				1
#define INTEF_FLAG2QW				2

// flags for the pflags field of entities
#define PFLAGS_NOSHADOW			1
#define PFLAGS_CORONA			2
#define PFLAGS_FULLDYNAMIC		128 // must be set or the light fields are ignored

// if the high bit of the servercmd is set, the low bits are fast update flags:
#define U_MOREBITS		(1<<0)
#define U_ORIGIN1		(1<<1)
#define U_ORIGIN2		(1<<2)
#define U_ORIGIN3		(1<<3)
#define U_ANGLE2		(1<<4)
// LordHavoc: U_NOLERP was only ever used for monsters, so I renamed it U_STEP
#define U_STEP			(1<<5)
#define U_FRAME			(1<<6)
// just differentiates from other updates
#define U_SIGNAL		(1<<7)

#define U_ANGLE1		(1<<8)
#define U_ANGLE3		(1<<9)
#define U_MODEL			(1<<10)
#define U_COLORMAP		(1<<11)
#define U_SKIN			(1<<12)
#define U_EFFECTS		(1<<13)
#define U_LONGENTITY	(1<<14)

// LordHavoc: protocol extension
#define U_EXTEND1		(1<<15)
// LordHavoc: first extend byte
#define U_DELTA			(1<<16) // no data, while this is set the entity is delta compressed (uses previous frame as a baseline, meaning only things that have changed from the previous frame are sent, except for the forced full update every half second)
#define U_ALPHA			(1<<17) // 1 byte, 0.0-1.0 maps to 0-255, not sent if exactly 1, and the entity is not sent if <=0 unless it has effects (model effects are checked as well)
#define U_SCALE			(1<<18) // 1 byte, scale / 16 positive, not sent if 1.0
#define U_EFFECTS2		(1<<19) // 1 byte, this is .effects & 0xFF00 (second byte)
#define U_GLOWSIZE		(1<<20) // 1 byte, encoding is float/4.0, unsigned, not sent if 0
#define U_GLOWCOLOR		(1<<21) // 1 byte, palette index, default is 254 (white), this IS used for darklight (allowing colored darklight), however the particles from a darklight are always black, not sent if default value (even if glowsize or glowtrail is set)
#define U_COLORMOD		(1<<22) // 1 byte, 3 bit red, 3 bit green, 2 bit blue, this lets you tint an object artifically, so you could make a red rocket, or a blue fiend...
#define U_EXTEND2		(1<<23) // another byte to follow
// LordHavoc: second extend byte
#define U_GLOWTRAIL		(1<<24) // leaves a trail of particles (of color .glowcolor, or black if it is a negative glowsize)
#define U_VIEWMODEL		(1<<25) // attachs the model to the view (origin and angles become relative to it), only shown to owner, a more powerful alternative to .weaponmodel and such
#define U_FRAME2		(1<<26) // 1 byte, this is .frame & 0xFF00 (second byte)
#define U_MODEL2		(1<<27) // 1 byte, this is .modelindex & 0xFF00 (second byte)
#define U_EXTERIORMODEL	(1<<28) // causes this model to not be drawn when using a first person view (third person will draw it, first person will not)
#define U_UNUSED29		(1<<29) // future expansion
#define U_UNUSED30		(1<<30) // future expansion
#define U_EXTEND3		(1<<31) // another byte to follow, future expansion

#define	SU_VIEWHEIGHT	(1<<0)
#define	SU_IDEALPITCH	(1<<1)
#define	SU_PUNCH1		(1<<2)
#define	SU_PUNCH2		(1<<3)
#define	SU_PUNCH3		(1<<4)
#define	SU_VELOCITY1	(1<<5)
#define	SU_VELOCITY2	(1<<6)
#define	SU_VELOCITY3	(1<<7)
//define	SU_AIMENT		(1<<8)  AVAILABLE BIT
#define	SU_ITEMS		(1<<9)
#define	SU_ONGROUND		(1<<10)		// no data follows, the bit is it
#define	SU_INWATER		(1<<11)		// no data follows, the bit is it
#define	SU_WEAPONFRAME	(1<<12)
#define	SU_ARMOR		(1<<13)
#define	SU_WEAPON		(1<<14)
#define SU_EXTEND1		(1<<15)
// first extend byte
#define SU_PUNCHVEC1	(1<<16)
#define SU_PUNCHVEC2	(1<<17)
#define SU_PUNCHVEC3	(1<<18)
#define SU_VIEWZOOM		(1<<19) // byte factor (0 = 0.0 (not valid), 255 = 1.0)
#define SU_UNUSED20		(1<<20)
#define SU_UNUSED21		(1<<21)
#define SU_UNUSED22		(1<<22)
#define SU_EXTEND2		(1<<23) // another byte to follow, future expansion
// second extend byte
#define SU_UNUSED24		(1<<24)
#define SU_UNUSED25		(1<<25)
#define SU_UNUSED26		(1<<26)
#define SU_UNUSED27		(1<<27)
#define SU_UNUSED28		(1<<28)
#define SU_UNUSED29		(1<<29)
#define SU_UNUSED30		(1<<30)
#define SU_EXTEND3		(1<<31) // another byte to follow, future expansion

// a sound with no channel is a local only sound
#define	SND_VOLUME		(1<<0)		// a byte
#define	SND_ATTENUATION	(1<<1)		// a byte
#define	SND_LOOPING		(1<<2)		// a long
#define	SND_LARGEENTITY	(1<<3)		// a short and a byte (instead of a short)
#define	SND_LARGESOUND	(1<<4)		// a short (instead of a byte)
#define	SND_SPEEDUSHORT4000	(1<<5)		// ushort speed*4000 (speed is usually 1.0, a value of 0.0 is the same as 1.0)


// defaults for clientinfo messages
#define	DEFAULT_VIEWHEIGHT	22


// game types sent by serverinfo
// these determine which intermission screen plays
#define	GAME_COOP			0
#define	GAME_DEATHMATCH		1

//==================
// note that there are some defs.qc that mirror to these numbers
// also related to svc_strings[] in cl_parse
//==================

//
// server to client
//
#define	svc_bad				0
#define	svc_nop				1
#define	svc_disconnect		2
#define	svc_updatestat		3	// [byte] [long]
#define	svc_version			4	// [long] server version
#define	svc_setview			5	// [short] entity number
#define	svc_sound			6	// <see code>
#define	svc_time			7	// [float] server time
#define	svc_print			8	// [string] null terminated string
#define	svc_stufftext		9	// [string] stuffed into client's console buffer
								// the string should be \n terminated
#define	svc_setangle		10	// [angle3] set the view angle to this absolute value

#define	svc_serverinfo		11	// [long] version
						// [string] signon string
						// [string]..[0]model cache
						// [string]...[0]sounds cache
#define	svc_lightstyle		12	// [byte] [string]
#define	svc_updatename		13	// [byte] [string]
#define	svc_updatefrags		14	// [byte] [short]
#define	svc_clientdata		15	// <shortbits + data>
#define	svc_stopsound		16	// <see code>
#define	svc_updatecolors	17	// [byte] [byte]
#define	svc_particle		18	// [vec3] <variable>
#define	svc_damage			19

#define	svc_spawnstatic		20
//	svc_spawnbinary		21
#define	svc_spawnbaseline	22

#define	svc_temp_entity		23

#define	svc_setpause		24	// [byte] on / off
#define	svc_signonnum		25	// [byte]  used for the signon sequence

#define	svc_centerprint		26	// [string] to put in center of the screen

#define	svc_killedmonster	27
#define	svc_foundsecret		28

#define	svc_spawnstaticsound	29	// [coord3] [byte] samp [byte] vol [byte] aten

#define	svc_intermission	30		// [string] music
#define	svc_finale			31		// [string] music [string] text

#define	svc_cdtrack			32		// [byte] track [byte] looptrack
#define svc_sellscreen		33

#define svc_cutscene		34

#define	svc_showlmp			35		// [string] slotname [string] lmpfilename [short] x [short] y
#define	svc_hidelmp			36		// [string] slotname
#define	svc_skybox			37		// [string] skyname

// LordHavoc: my svc_ range, 50-69
#define svc_downloaddata	50		// [int] start [short] size
#define svc_updatestatubyte	51		// [byte] stat [byte] value
#define svc_effect			52		// [vector] org [byte] modelindex [byte] startframe [byte] framecount [byte] framerate
#define svc_effect2			53		// [vector] org [short] modelindex [short] startframe [byte] framecount [byte] framerate
#define	svc_sound2			54		// (obsolete in DP6 and later) short soundindex instead of byte
#define	svc_precache		54		// [short] precacheindex [string] filename, precacheindex is + 0 for modelindex and +32768 for soundindex
#define	svc_spawnbaseline2	55		// short modelindex instead of byte
#define svc_spawnstatic2	56		// short modelindex instead of byte
#define svc_entities		57		// [int] deltaframe [int] thisframe [float vector] eye [variable length] entitydata
#define svc_csqcentities	58		// [short] entnum [variable length] entitydata ... [short] 0x0000
#define	svc_spawnstaticsound2	59	// [coord3] [short] samp [byte] vol [byte] aten
#define svc_trailparticles	60		// [short] entnum [short] effectnum [vector] start [vector] end
#define svc_pointparticles	61		// [short] effectnum [vector] start [vector] velocity [short] count
#define svc_pointparticles1	62		// [short] effectnum [vector] start, same as svc_pointparticles except velocity is zero and count is 1

//
// client to server
//
#define	clc_bad			0
#define	clc_nop 		1
#define	clc_disconnect	2
#define	clc_move		3			// [usercmd_t]
#define	clc_stringcmd	4		// [string] message

// LordHavoc: my clc_ range, 50-59
#define clc_ackframe	50		// [int] framenumber
#define clc_ackdownloaddata	51	// [int] start [short] size   (note: exact echo of latest values received in svc_downloaddata, packet-loss handling is in the server)
#define clc_unusedlh2 	52
#define clc_unusedlh3 	53
#define clc_unusedlh4 	54
#define clc_unusedlh5 	55
#define clc_unusedlh6 	56
#define clc_unusedlh7 	57
#define clc_unusedlh8 	58
#define clc_unusedlh9 	59

//
// temp entity events
//
#define	TE_SPIKE			0 // [vector] origin
#define	TE_SUPERSPIKE		1 // [vector] origin
#define	TE_GUNSHOT			2 // [vector] origin
#define	TE_EXPLOSION		3 // [vector] origin
#define	TE_TAREXPLOSION		4 // [vector] origin
#define	TE_LIGHTNING1		5 // [entity] entity [vector] start [vector] end
#define	TE_LIGHTNING2		6 // [entity] entity [vector] start [vector] end
#define	TE_WIZSPIKE			7 // [vector] origin
#define	TE_KNIGHTSPIKE		8 // [vector] origin
#define	TE_LIGHTNING3		9 // [entity] entity [vector] start [vector] end
#define	TE_LAVASPLASH		10 // [vector] origin
#define	TE_TELEPORT			11 // [vector] origin
#define TE_EXPLOSION2		12 // [vector] origin [byte] startcolor [byte] colorcount

// PGM 01/21/97
#define TE_BEAM				13 // [entity] entity [vector] start [vector] end
// PGM 01/21/97

// Nehahra effects used in the movie (TE_EXPLOSION3 also got written up in a QSG tutorial, hence it's not marked NEH)
#define	TE_EXPLOSION3		16 // [vector] origin [coord] red [coord] green [coord] blue
#define TE_LIGHTNING4NEH	17 // [string] model [entity] entity [vector] start [vector] end

// LordHavoc: added some TE_ codes (block1 - 50-60)
#define	TE_BLOOD			50 // [vector] origin [byte] xvel [byte] yvel [byte] zvel [byte] count
#define	TE_SPARK			51 // [vector] origin [byte] xvel [byte] yvel [byte] zvel [byte] count
#define	TE_BLOODSHOWER		52 // [vector] min [vector] max [coord] explosionspeed [short] count
#define	TE_EXPLOSIONRGB		53 // [vector] origin [byte] red [byte] green [byte] blue
#define TE_PARTICLECUBE		54 // [vector] min [vector] max [vector] dir [short] count [byte] color [byte] gravity [coord] randomvel
#define TE_PARTICLERAIN		55 // [vector] min [vector] max [vector] dir [short] count [byte] color
#define TE_PARTICLESNOW		56 // [vector] min [vector] max [vector] dir [short] count [byte] color
#define TE_GUNSHOTQUAD		57 // [vector] origin
#define TE_SPIKEQUAD		58 // [vector] origin
#define TE_SUPERSPIKEQUAD	59 // [vector] origin
// LordHavoc: block2 - 70-80
#define TE_EXPLOSIONQUAD	70 // [vector] origin
#define	TE_UNUSED1			71 // unused
#define TE_SMALLFLASH		72 // [vector] origin
#define TE_CUSTOMFLASH		73 // [vector] origin [byte] radius / 8 - 1 [byte] lifetime / 256 - 1 [byte] red [byte] green [byte] blue
#define TE_FLAMEJET			74 // [vector] origin [vector] velocity [byte] count
#define TE_PLASMABURN		75 // [vector] origin
// LordHavoc: Tei grabbed these codes
#define TE_TEI_G3			76 // [vector] start [vector] end [vector] angles
#define TE_TEI_SMOKE		77 // [vector] origin [vector] dir [byte] count
#define TE_TEI_BIGEXPLOSION	78 // [vector] origin
#define TE_TEI_PLASMAHIT	79 // [vector} origin [vector] dir [byte] count


// these are bits for the 'flags' field of the entity_state_t
#define RENDER_STEP 1
#define RENDER_GLOWTRAIL 2
#define RENDER_VIEWMODEL 4
#define RENDER_EXTERIORMODEL 8
#define RENDER_LOWPRECISION 16 // send as low precision coordinates to save bandwidth
#define RENDER_COLORMAPPED 32
#define RENDER_WORLDOBJECT 64 // do not cull this entity with r_cullentities
#define RENDER_COMPLEXANIMATION 128

#define RENDER_SHADOW 65536 // cast shadow
#define RENDER_LIGHT 131072 // receive light
#define RENDER_NOSELFSHADOW 262144 // render lighting on this entity before its own shadow is added to the scene
// (note: all RENDER_NOSELFSHADOW entities are grouped together and rendered in a batch before their shadows are rendered, so they can not shadow eachother either)
#define RENDER_EQUALIZE 524288 // (subflag of RENDER_LIGHT) equalize the light from the light grid hitting this ent (less invasive EF_FULLBRIGHT implementation)
#define RENDER_NODEPTHTEST 1048576
#define RENDER_ADDITIVE 2097152
#define RENDER_DOUBLESIDED 4194304
#define RENDER_CUSTOMIZEDMODELLIGHT 4096
#define RENDER_DYNAMICMODELLIGHT 8388608 // origin dependent model light

#define MAX_FRAMEGROUPBLENDS 4
typedef struct framegroupblend_s
{
	// animation number and blend factor
	// (for most models this is the frame number)
	int frame;
	float lerp;
	// time frame began playing (for framegroup animations)
	double start;
}
framegroupblend_t;

struct matrix4x4_s;
struct model_s;

typedef struct skeleton_s
{
	const struct model_s *model;
	struct matrix4x4_s *relativetransforms;
}
skeleton_t;

typedef enum entity_state_active_e
{
	ACTIVE_NOT = 0,
	ACTIVE_NETWORK = 1,
	ACTIVE_SHARED = 2
}
entity_state_active_t;

// this was 96 bytes, now 168 bytes (32bit) or 176 bytes (64bit)
typedef struct entity_state_s
{
	// ! means this is not sent to client
	double time; // ! time this state was built (used on client for interpolation)
	float netcenter[3]; // ! for network prioritization, this is the center of the bounding box (which may differ from the origin)
	float origin[3];
	float angles[3];
	int effects;
	unsigned int customizeentityforclient; // !
	unsigned short number; // entity number this state is for
	unsigned short modelindex;
	unsigned short frame;
	unsigned short tagentity;
	unsigned short specialvisibilityradius; // ! larger if it has effects/light
	unsigned short viewmodelforclient; // !
	unsigned short exteriormodelforclient; // ! not shown if first person viewing from this entity, shown in all other cases
	unsigned short nodrawtoclient; // !
	unsigned short drawonlytoclient; // !
	unsigned short traileffectnum;
	unsigned short light[4]; // color*256 (0.00 to 255.996), and radius*1
	unsigned char active; // true if a valid state
	unsigned char lightstyle;
	unsigned char lightpflags;
	unsigned char colormap;
	unsigned char skin; // also chooses cubemap for rtlights if lightpflags & LIGHTPFLAGS_FULLDYNAMIC
	unsigned char alpha;
	unsigned char scale;
	unsigned char glowsize;
	unsigned char glowcolor;
	unsigned char flags;
	unsigned char internaleffects; // INTEF_FLAG1QW and so on
	unsigned char tagindex;
	unsigned char colormod[3];
	unsigned char glowmod[3];
	// LordHavoc: very big data here :(
	framegroupblend_t framegroupblend[4];
	skeleton_t skeletonobject;
}
entity_state_t;

// baseline state values
extern entity_state_t defaultstate;
// reads a quake entity from the network stream
void EntityFrameQuake_ReadEntity(int bits);
// checks for stats changes and sets corresponding host_client->statsdeltabits
// (also updates host_client->stats array)
void Protocol_UpdateClientStats(const int *stats);
// writes reliable messages updating stats (not used by DP6 and later
// protocols which send updates in their WriteFrame function using a different
// method of reliable messaging)
void Protocol_WriteStatsReliable(void);
// writes a list of quake entities to the network stream
// (or as many will fit)
qboolean EntityFrameQuake_WriteFrame(sizebuf_t *msg, int maxsize, int numstates, const entity_state_t **states);
// cleans up dead entities each frame after ReadEntity (which doesn't clear unused entities)
void EntityFrameQuake_ISeeDeadEntities(void);

/*
PROTOCOL_DARKPLACES3
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.
*/

/*
PROTOCOL_DARKPLACES4
a frame consists of some visible entities in a range (this is stored as start and end, note that end may be less than start if it wrapped).

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. build an entity_frame_t using appropriate functions, containing (some of) the visible entities, this is passed to the Write function to send it.

This documention is unfinished!
the Write function performs these steps:
1. check if entity frame is larger than MAX_ENTITYFRAME or is larger than available space in database, if so the baseline is defaults, otherwise it is the current baseline of the database.
2. write differences of an entity compared to selected baseline.
3. add entity to entity update in database.
4. if there are more entities to write and packet is not full, go back to step 2.
5. write terminator (0xFFFF) as entity number.
6. return.





server updates entities in looping ranges, a frame consists of a range of visible entities (not always all visible entities),
*/

#define MAX_ENTITY_HISTORY 64
#define MAX_ENTITY_DATABASE (MAX_EDICTS * 2)

// build entity data in this, to pass to entity read/write functions
typedef struct entity_frame_s
{
	double time;
	int framenum;
	int numentities;
	int firstentitynum;
	int lastentitynum;
	vec3_t eye;
	entity_state_t entitydata[MAX_ENTITY_DATABASE];
}
entity_frame_t;

typedef struct entity_frameinfo_s
{
	double time;
	int framenum;
	int firstentity; // index into entitydata, modulo MAX_ENTITY_DATABASE
	int endentity; // index into entitydata, firstentity + numentities
}
entity_frameinfo_t;

typedef struct entityframe_database_s
{
	// 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 sent frame
	int latestframenum;
	// server only: last acknowledged frame
	int ackframenum;
	// 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];

	// structs for building new frames and reading them
	entity_frame_t deltaframe;
	entity_frame_t framedata;
}
entityframe_database_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_LIGHT			(1<<21)
#define E_LIGHTPFLAGS	(1<<22)
#define E_EXTEND3		(1<<23)

#define E_SOUND1		(1<<24)
#define E_SOUNDVOL		(1<<25)
#define E_SOUNDATTEN	(1<<26)
#define E_TAGATTACHMENT	(1<<27)
#define E_LIGHTSTYLE	(1<<28)
#define E_UNUSED6		(1<<29)
#define E_UNUSED7		(1<<30)
#define E_EXTEND4		(1<<31)

// returns difference between two states as E_ flags
int EntityState_DeltaBits(const entity_state_t *o, const entity_state_t *n);
// write E_ flags to a msg
void EntityState_WriteExtendBits(sizebuf_t *msg, unsigned int bits);
// write values for the E_ flagged fields to a msg
void EntityState_WriteFields(const entity_state_t *ent, sizebuf_t *msg, unsigned int bits);
// write entity number and E_ flags and their values, or a remove number, describing the change from delta to ent
void EntityState_WriteUpdate(const entity_state_t *ent, sizebuf_t *msg, const entity_state_t *delta);
// read E_ flags
int EntityState_ReadExtendBits(void);
// read values for E_ flagged fields and apply them to a state
void EntityState_ReadFields(entity_state_t *e, unsigned int bits);

// (client and server) allocates a new empty database
entityframe_database_t *EntityFrame_AllocDatabase(mempool_t *mempool);
// (client and server) frees the database
void EntityFrame_FreeDatabase(entityframe_database_t *d);
// (server) clears the database to contain no frames (thus delta compression
// compresses against nothing)
void EntityFrame_ClearDatabase(entityframe_database_t *d);
// (server and client) removes frames older than 'frame' from database
void EntityFrame_AckFrame(entityframe_database_t *d, int frame);
// (server) clears frame, to prepare for adding entities
void EntityFrame_Clear(entity_frame_t *f, vec3_t eye, int framenum);
// (server and client) reads a frame from the database
void EntityFrame_FetchFrame(entityframe_database_t *d, int framenum, entity_frame_t *f);
// (client) adds a entity_frame to the database, for future reference
void EntityFrame_AddFrame_Client(entityframe_database_t *d, vec3_t eye, int framenum, int numentities, const entity_state_t *entitydata);
// (server) adds a entity_frame to the database, for future reference
void EntityFrame_AddFrame_Server(entityframe_database_t *d, vec3_t eye, int framenum, int numentities, const entity_state_t **entitydata);
// (server) writes a frame to network stream
qboolean EntityFrame_WriteFrame(sizebuf_t *msg, int maxsize, entityframe_database_t *d, int numstates, const entity_state_t **states, int viewentnum);
// (client) reads a frame from network stream
void EntityFrame_CL_ReadFrame(void);
// (client) returns the frame number of the most recent frame recieved
int EntityFrame_MostRecentlyRecievedFrameNum(entityframe_database_t *d);

typedef struct entity_database4_commit_s
{
	// frame number this commit represents
	int framenum;
	// number of entities in entity[] array
	int numentities;
	// maximum number of entities in entity[] array (dynamic resizing)
	int maxentities;
	entity_state_t *entity;
}
entity_database4_commit_t;

typedef struct entity_database4_s
{
	// what mempool to use for allocations
	mempool_t *mempool;
	// reference frame
	int referenceframenum;
	// reference entities array is resized according to demand
	int maxreferenceentities;
	// array of states for entities, these are indexable by their entity number (yes there are gaps)
	entity_state_t *referenceentity;
	// commits waiting to be applied to the reference database when confirmed
	// (commit[i]->numentities == 0 means it is empty)
	entity_database4_commit_t commit[MAX_ENTITY_HISTORY];
	// (server only) the current commit being worked on
	entity_database4_commit_t *currentcommit;
	// (server only) if a commit won't fit entirely, continue where it left
	// off next frame
	int currententitynumber;
	// (server only)
	int latestframenumber;
}
entityframe4_database_t;

// should-be-private functions that aren't
entity_state_t *EntityFrame4_GetReferenceEntity(entityframe4_database_t *d, int number);
void EntityFrame4_AddCommitEntity(entityframe4_database_t *d, const entity_state_t *s);

// allocate a database
entityframe4_database_t *EntityFrame4_AllocDatabase(mempool_t *pool);
// free a database
void EntityFrame4_FreeDatabase(entityframe4_database_t *d);
// reset a database (resets compression but does not reallocate anything)
void EntityFrame4_ResetDatabase(entityframe4_database_t *d);
// updates database to account for a frame-received acknowledgment
int EntityFrame4_AckFrame(entityframe4_database_t *d, int framenum, int servermode);
// writes a frame to the network stream
qboolean EntityFrame4_WriteFrame(sizebuf_t *msg, int maxsize, entityframe4_database_t *d, int numstates, const entity_state_t **states);
// reads a frame from the network stream
void EntityFrame4_CL_ReadFrame(void);

// reset all entity fields (typically used if status changed)
#define E5_FULLUPDATE (1<<0)
// E5_ORIGIN32=0: short[3] = s->origin[0] * 8, s->origin[1] * 8, s->origin[2] * 8
// E5_ORIGIN32=1: float[3] = s->origin[0], s->origin[1], s->origin[2]
#define E5_ORIGIN (1<<1)
// E5_ANGLES16=0: byte[3] = s->angle[0] * 256 / 360, s->angle[1] * 256 / 360, s->angle[2] * 256 / 360
// E5_ANGLES16=1: short[3] = s->angle[0] * 65536 / 360, s->angle[1] * 65536 / 360, s->angle[2] * 65536 / 360
#define E5_ANGLES (1<<2)
// E5_MODEL16=0: byte = s->modelindex
// E5_MODEL16=1: short = s->modelindex
#define E5_MODEL (1<<3)
// E5_FRAME16=0: byte = s->frame
// E5_FRAME16=1: short = s->frame
#define E5_FRAME (1<<4)
// byte = s->skin
#define E5_SKIN (1<<5)
// E5_EFFECTS16=0 && E5_EFFECTS32=0: byte = s->effects
// E5_EFFECTS16=1 && E5_EFFECTS32=0: short = s->effects
// E5_EFFECTS16=0 && E5_EFFECTS32=1: int = s->effects
// E5_EFFECTS16=1 && E5_EFFECTS32=1: int = s->effects
#define E5_EFFECTS (1<<6)
// bits >= (1<<8)
#define E5_EXTEND1 (1<<7)

// byte = s->renderflags
#define E5_FLAGS (1<<8)
// byte = bound(0, s->alpha * 255, 255)
#define E5_ALPHA (1<<9)
// byte = bound(0, s->scale * 16, 255)
#define E5_SCALE (1<<10)
// flag
#define E5_ORIGIN32 (1<<11)
// flag
#define E5_ANGLES16 (1<<12)
// flag
#define E5_MODEL16 (1<<13)
// byte = s->colormap
#define E5_COLORMAP (1<<14)
// bits >= (1<<16)
#define E5_EXTEND2 (1<<15)

// short = s->tagentity
// byte = s->tagindex
#define E5_ATTACHMENT (1<<16)
// short[4] = s->light[0], s->light[1], s->light[2], s->light[3]
// byte = s->lightstyle
// byte = s->lightpflags
#define E5_LIGHT (1<<17)
// byte = s->glowsize
// byte = s->glowcolor
#define E5_GLOW (1<<18)
// short = s->effects
#define E5_EFFECTS16 (1<<19)
// int = s->effects
#define E5_EFFECTS32 (1<<20)
// flag
#define E5_FRAME16 (1<<21)
// byte[3] = s->colormod[0], s->colormod[1], s->colormod[2]
#define E5_COLORMOD (1<<22)
// bits >= (1<<24)
#define E5_EXTEND3 (1<<23)

// byte[3] = s->glowmod[0], s->glowmod[1], s->glowmod[2]
#define E5_GLOWMOD (1<<24)
// byte type=0 short frames[1] short times[1]
// byte type=1 short frames[2] short times[2] byte lerps[2]
// byte type=2 short frames[3] short times[3] byte lerps[3]
// byte type=3 short frames[4] short times[4] byte lerps[4]
// byte type=4 short modelindex byte numbones {short pose7s[7]}
// see also RENDER_COMPLEXANIMATION
#define E5_COMPLEXANIMATION (1<<25)
// ushort traileffectnum
#define E5_TRAILEFFECTNUM (1<<26)
// unused
#define E5_UNUSED27 (1<<27)
// unused
#define E5_UNUSED28 (1<<28)
// unused
#define E5_UNUSED29 (1<<29)
// unused
#define E5_UNUSED30 (1<<30)
// bits2 > 0
#define E5_EXTEND4 (1<<31)

#define ENTITYFRAME5_MAXPACKETLOGS 64
#define ENTITYFRAME5_MAXSTATES 1024
#define ENTITYFRAME5_PRIORITYLEVELS 32

typedef struct entityframe5_changestate_s
{
	unsigned int number;
	unsigned int bits;
}
entityframe5_changestate_t;

typedef struct entityframe5_packetlog_s
{
	int packetnumber;
	int numstates;
	entityframe5_changestate_t states[ENTITYFRAME5_MAXSTATES];
	unsigned char statsdeltabits[(MAX_CL_STATS+7)/8];
}
entityframe5_packetlog_t;

typedef struct entityframe5_database_s
{
	// number of the latest message sent to client
	int latestframenum;
	// updated by WriteFrame for internal use
	int viewentnum;

	// logs of all recently sent messages (between acked and latest)
	entityframe5_packetlog_t packetlog[ENTITYFRAME5_MAXPACKETLOGS];

	// this goes up as needed and causes all the arrays to be reallocated
	int maxedicts;

	// which properties of each entity have changed since last send
	int *deltabits; // [maxedicts]
	// priorities of entities (updated whenever deltabits change)
	// (derived from deltabits)
	unsigned char *priorities; // [maxedicts]
	// last frame this entity was sent on, for prioritzation
	int *updateframenum; // [maxedicts]

	// database of current status of all entities
	entity_state_t *states; // [maxedicts]
	// which entities are currently active
	// (duplicate of the active bit of every state in states[])
	// (derived from states)
	unsigned char *visiblebits; // [(maxedicts+7)/8]

	// old notes

	// this is used to decide which changestates to set each frame
	//int numvisiblestates;
	//entity_state_t visiblestates[MAX_EDICTS];

	// sorted changing states that need to be sent to the client
	// kept sorted in lowest to highest priority order, because this allows
	// the numchangestates to simply be decremented whenever an state is sent,
	// rather than a memmove to remove them from the start.
	//int numchangestates;
	//entityframe5_changestate_t changestates[MAX_EDICTS];

	// buffers for building priority info
	int prioritychaincounts[ENTITYFRAME5_PRIORITYLEVELS];
	unsigned short prioritychains[ENTITYFRAME5_PRIORITYLEVELS][ENTITYFRAME5_MAXSTATES];
}
entityframe5_database_t;

entityframe5_database_t *EntityFrame5_AllocDatabase(mempool_t *pool);
void EntityFrame5_FreeDatabase(entityframe5_database_t *d);
void EntityState5_WriteUpdate(int number, const entity_state_t *s, int changedbits, sizebuf_t *msg);
int EntityState5_DeltaBitsForState(entity_state_t *o, entity_state_t *n);
void EntityFrame5_CL_ReadFrame(void);
void EntityFrame5_LostFrame(entityframe5_database_t *d, int framenum);
void EntityFrame5_AckFrame(entityframe5_database_t *d, int framenum);
qboolean EntityFrame5_WriteFrame(sizebuf_t *msg, int maxsize, entityframe5_database_t *d, int numstates, const entity_state_t **states, int viewentnum, int movesequence, qboolean need_empty);

extern cvar_t developer_networkentities;

// QUAKEWORLD
// server to client
#define qw_svc_bad				0
#define qw_svc_nop				1
#define qw_svc_disconnect		2
#define qw_svc_updatestat		3	// [byte] [byte]
#define qw_svc_setview			5	// [short] entity number
#define qw_svc_sound			6	// <see code>
#define qw_svc_print			8	// [byte] id [string] null terminated string
#define qw_svc_stufftext		9	// [string] stuffed into client's console buffer
#define qw_svc_setangle			10	// [angle3] set the view angle to this absolute value
#define qw_svc_serverdata		11	// [long] protocol ...
#define qw_svc_lightstyle		12	// [byte] [string]
#define qw_svc_updatefrags		14	// [byte] [short]
#define qw_svc_stopsound		16	// <see code>
#define qw_svc_damage			19
#define qw_svc_spawnstatic		20
#define qw_svc_spawnbaseline	22
#define qw_svc_temp_entity		23	// variable
#define qw_svc_setpause			24	// [byte] on / off
#define qw_svc_centerprint		26	// [string] to put in center of the screen
#define qw_svc_killedmonster	27
#define qw_svc_foundsecret		28
#define qw_svc_spawnstaticsound	29	// [coord3] [byte] samp [byte] vol [byte] aten
#define qw_svc_intermission		30		// [vec3_t] origin [vec3_t] angle
#define qw_svc_finale			31		// [string] text
#define qw_svc_cdtrack			32		// [byte] track
#define qw_svc_sellscreen		33
#define qw_svc_smallkick		34		// set client punchangle to 2
#define qw_svc_bigkick			35		// set client punchangle to 4
#define qw_svc_updateping		36		// [byte] [short]
#define qw_svc_updateentertime	37		// [byte] [float]
#define qw_svc_updatestatlong	38		// [byte] [long]
#define qw_svc_muzzleflash		39		// [short] entity
#define qw_svc_updateuserinfo	40		// [byte] slot [long] uid
#define qw_svc_download			41		// [short] size [size bytes]
#define qw_svc_playerinfo		42		// variable
#define qw_svc_nails			43		// [byte] num [48 bits] xyzpy 12 12 12 4 8
#define qw_svc_chokecount		44		// [byte] packets choked
#define qw_svc_modellist		45		// [strings]
#define qw_svc_soundlist		46		// [strings]
#define qw_svc_packetentities	47		// [...]
#define qw_svc_deltapacketentities	48		// [...]
#define qw_svc_maxspeed			49		// maxspeed change, for prediction
#define qw_svc_entgravity		50		// gravity change, for prediction
#define qw_svc_setinfo			51		// setinfo on a client
#define qw_svc_serverinfo		52		// serverinfo
#define qw_svc_updatepl			53		// [byte] [byte]
// QUAKEWORLD
// client to server
#define qw_clc_bad			0
#define qw_clc_nop			1
#define qw_clc_move			3		// [[usercmd_t]
#define qw_clc_stringcmd	4		// [string] message
#define qw_clc_delta		5		// [byte] sequence number, requests delta compression of message
#define qw_clc_tmove		6		// teleport request, spectator only
#define qw_clc_upload		7		// teleport request, spectator only
// QUAKEWORLD
// playerinfo flags from server
// playerinfo always sends: playernum, flags, origin[] and framenumber
#define	QW_PF_MSEC			(1<<0)
#define	QW_PF_COMMAND		(1<<1)
#define	QW_PF_VELOCITY1	(1<<2)
#define	QW_PF_VELOCITY2	(1<<3)
#define	QW_PF_VELOCITY3	(1<<4)
#define	QW_PF_MODEL		(1<<5)
#define	QW_PF_SKINNUM		(1<<6)
#define	QW_PF_EFFECTS		(1<<7)
#define	QW_PF_WEAPONFRAME	(1<<8)		// only sent for view player
#define	QW_PF_DEAD			(1<<9)		// don't block movement any more
#define	QW_PF_GIB			(1<<10)		// offset the view height differently
#define	QW_PF_NOGRAV		(1<<11)		// don't apply gravity for prediction
// QUAKEWORLD
// if the high bit of the client to server byte is set, the low bits are
// client move cmd bits
// ms and angle2 are allways sent, the others are optional
#define QW_CM_ANGLE1 	(1<<0)
#define QW_CM_ANGLE3 	(1<<1)
#define QW_CM_FORWARD	(1<<2)
#define QW_CM_SIDE		(1<<3)
#define QW_CM_UP		(1<<4)
#define QW_CM_BUTTONS	(1<<5)
#define QW_CM_IMPULSE	(1<<6)
#define QW_CM_ANGLE2 	(1<<7)
// QUAKEWORLD
// the first 16 bits of a packetentities update holds 9 bits
// of entity number and 7 bits of flags
#define QW_U_ORIGIN1	(1<<9)
#define QW_U_ORIGIN2	(1<<10)
#define QW_U_ORIGIN3	(1<<11)
#define QW_U_ANGLE2		(1<<12)
#define QW_U_FRAME		(1<<13)
#define QW_U_REMOVE		(1<<14)		// REMOVE this entity, don't add it
#define QW_U_MOREBITS	(1<<15)
// if MOREBITS is set, these additional flags are read in next
#define QW_U_ANGLE1		(1<<0)
#define QW_U_ANGLE3		(1<<1)
#define QW_U_MODEL		(1<<2)
#define QW_U_COLORMAP	(1<<3)
#define QW_U_SKIN		(1<<4)
#define QW_U_EFFECTS	(1<<5)
#define QW_U_SOLID		(1<<6)		// the entity should be solid for prediction
// QUAKEWORLD
// temp entity events
#define QW_TE_SPIKE				0
#define QW_TE_SUPERSPIKE		1
#define QW_TE_GUNSHOT			2
#define QW_TE_EXPLOSION			3
#define QW_TE_TAREXPLOSION		4
#define QW_TE_LIGHTNING1		5
#define QW_TE_LIGHTNING2		6
#define QW_TE_WIZSPIKE			7
#define QW_TE_KNIGHTSPIKE		8
#define QW_TE_LIGHTNING3		9
#define QW_TE_LAVASPLASH		10
#define QW_TE_TELEPORT			11
#define QW_TE_BLOOD				12
#define QW_TE_LIGHTNINGBLOOD	13
// QUAKEWORLD
// effect flags
#define QW_EF_BRIGHTFIELD		1
#define QW_EF_MUZZLEFLASH 		2
#define QW_EF_BRIGHTLIGHT 		4
#define QW_EF_DIMLIGHT 			8
#define QW_EF_FLAG1	 			16
#define QW_EF_FLAG2	 			32
#define QW_EF_BLUE				64
#define QW_EF_RED				128

#define QW_UPDATE_BACKUP 64
#define QW_UPDATE_MASK (QW_UPDATE_BACKUP - 1)
#define QW_MAX_PACKET_ENTITIES 64

// note: QW stats are directly compatible with NQ
// (but FRAGS, WEAPONFRAME, and VIEWHEIGHT are unused)
// so these defines are not actually used by darkplaces, but kept for reference
#define QW_STAT_HEALTH			0
//#define QW_STAT_FRAGS			1
#define QW_STAT_WEAPON			2
#define QW_STAT_AMMO			3
#define QW_STAT_ARMOR			4
//#define QW_STAT_WEAPONFRAME		5
#define QW_STAT_SHELLS			6
#define QW_STAT_NAILS			7
#define QW_STAT_ROCKETS			8
#define QW_STAT_CELLS			9
#define QW_STAT_ACTIVEWEAPON	10
#define QW_STAT_TOTALSECRETS	11
#define QW_STAT_TOTALMONSTERS	12
#define QW_STAT_SECRETS			13 // bumped on client side by svc_foundsecret
#define QW_STAT_MONSTERS		14 // bumped by svc_killedmonster
#define QW_STAT_ITEMS			15
//#define QW_STAT_VIEWHEIGHT		16

// build entity data in this, to pass to entity read/write functions
typedef struct entityframeqw_snapshot_s
{
	double time;
	qboolean invalid;
	int num_entities;
	entity_state_t entities[QW_MAX_PACKET_ENTITIES];
}
entityframeqw_snapshot_t;

typedef struct entityframeqw_database_s
{
	entityframeqw_snapshot_t snapshot[QW_UPDATE_BACKUP];
}
entityframeqw_database_t;

entityframeqw_database_t *EntityFrameQW_AllocDatabase(mempool_t *pool);
void EntityFrameQW_FreeDatabase(entityframeqw_database_t *d);
void EntityStateQW_ReadPlayerUpdate(void);
void EntityFrameQW_CL_ReadFrame(qboolean delta);

struct client_s;
void EntityFrameCSQC_LostFrame(struct client_s *client, int framenum);
qboolean EntityFrameCSQC_WriteFrame (sizebuf_t *msg, int maxsize, int numnumbers, const unsigned short *numbers, int framenum);

#endif

