quakeforge-old/common/cvar.h

/*
cvar.h
Copyright (C) 1996-1997 Id Software, Inc.
Copyright (C) 1999,2000  contributors of the QuakeForge project
Please see the file "AUTHORS" for a list of contributors

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.

*/

#ifndef _CVAR_H
#define _CVAR_H

#include <qtypes.h>
#include <quakeio.h>
/*

cvar_t variables are used to hold scalar or string variables that can be changed or displayed at the console or prog code as well as accessed directly
in C code.

it is sufficient to initialize a cvar_t with just the first two fields, or
you can add a ,true flag for variables that you want saved to the configuration
file when the game is quit:

cvar_t	r_draworder = {"r_draworder","1"};
cvar_t	scr_screensize = {"screensize","1",true};

Cvars must be registered before use, or they will have a 0 value instead of the float interpretation of the string.  Generally, all cvar_t declarations should be registered in the apropriate init function before any console commands are executed:
Cvar_RegisterVariable (&host_framerate);


C code usually just references a cvar in place:
if ( r_draworder.value )

It could optionally ask for the value to be looked up for a string name:
if (Cvar_VariableValue ("r_draworder"))

Interpreted prog code can access cvars with the cvar(name) or
cvar_set (name, value) internal functions:
teamplay = cvar("teamplay");

The user can access cvars from the console in two ways:
r_draworder			prints the current value
r_draworder 0		sets the current value to 0
Cvars are restricted from having the same names as commands to keep this
interface from being ambiguous.
*/

typedef struct cvar_s
{
	char    *name;
	char    *string;
	unsigned int	type;
	qboolean first;		// determine if this is the first write
//	qboolean archive;	// set to true to cause it to be saved to vars.rc
//	qboolean info;		// added to serverinfo or userinfo when changed
//	qboolean server;	// notifies players when changed (UQUAKE)
//	qboolean heap;		// allocated off the heap, safe to free
	float   value;
	struct cvar_s *next;
} cvar_t;

#define CVAR_NONE		0
#define	CVAR_ARCHIVE		1	// set to cause it to be saved to vars.rc
								// used for system variables, not for player
								// specific configurations
#define	CVAR_USERINFO		2	// sent to server on connect or change
#define	CVAR_SERVERINFO		4	// sent in response to front end requests
#define	CVAR_SYSTEMINFO		8	// these cvars will be duplicated on all clients
#define	CVAR_INIT			16	// don't allow change from console at all,
								// but can be set from the command line
#define	CVAR_NOTIFY			32	// Will notify players when changed.

#define	CVAR_ROM			64	// display only, cannot be set by user at all
#define	CVAR_USER_CREATED	128	// created by a set command
#define	CVAR_HEAP			256	// allocated off the heap, safe to free 
#define CVAR_CHEAT			512	// can not be changed if cheats are disabled
#define CVAR_NORESTART		1024	// do not clear when a cvar_restart is issued

// Zoid| A good CVAR_ROM example is basepath.  The code should read "cvar_t
// *fs_basepath = CvarGet("fs_basepath", ".", CVAR_ROM);  The user can
// override that with +set fs_basepath <blah> since the command line +set gets
// created _before_ the C code for fs_basepath setup is called.  The code goes
// "look, the user made fs_basepath already", uses the users value, but sets
// CVAR_ROM as per the call.

void 	Cvar_RegisterVariable (cvar_t *variable);
// registers a cvar that allready has the name, string, and optionally the
// archive elements set.

void 	Cvar_Set (char *var_name, char *value);
// equivelant to "<name> <variable>" typed at the console

void	Cvar_SetValue (char *var_name, float value);
// expands value to a string and calls Cvar_Set

float	Cvar_VariableValue (char *var_name);
// returns 0 if not defined or non numeric

char	*Cvar_VariableString (char *var_name);
// returns an empty string if not defined

char 	*Cvar_CompleteVariable (char *partial);
// attempts to match a partial variable name for command line completion
// returns NULL if nothing fits

qboolean Cvar_Command (void);
// called by Cmd_ExecuteString when Cmd_Argv(0) doesn't match a known
// command.  Returns true if the command was a variable reference that
// was handled. (print or change)

void 	Cvar_WriteVariables (QFile *f);
// Writes lines containing "set variable value" for all variables
// with the archive flag set to true.

cvar_t *Cvar_FindVar (char *var_name);

void Cvar_Init();

extern cvar_t	*cvar_vars;
#endif // _CVAR_H