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0x1337c0de / Toward a Better MOTD
« on: September 21, 2013, 07:37:41 PM »
LOX has a feature that sends a motto of the day (MOTD) to players when they connect. This code was originally in-line in the ClientBeginDeathmatch function and it was an UGLY part of an otherwise simple ClientBeginDeathmatch function.
Today I decided to clean it up a bit, make it a callable function and publish it for use by other mod developers who might be interested in using a MOTD in their mod. I don't know where the original code came from, it was a part of LOX from a very long time ago and also exists in WODX and presumably WOD from where LOX and WODX derive their pedigree.
ClientBeginDeathmatch isn't called frequently so there is no advantage to writing the code in-line and avoiding a function call. It also goes against discipline to write something in line where a function will be more advantageous and the resulting code much more clear.
The ClientPrintMOTD function prototype belongs at the top of p_client.c or in g_local.h if you intend to access it globally:
void ClientPrintMOTD (edict_t *ent);
The function body belongs in p_client.c:
Define the necessary CVAR in GameInit:
Add the CVAR to g_local.h:
Restore the ClientBeginDeathmatch to it's original beauty.
You will notice the ClientPrintMOTD function has a trapdoor in the gMOTD pointer. It's initialized at definition to -1 and the function sets it to NULL if there's a problem initializing the cache it is supposed point to that contains the MOTD text. I'm not sure I would have done it exactly that way but you may see a modified version later, I decided to publish this as-is and may polish it up another time. The trapdoor closes the first time the function is called and the gMOTD pointer either points to a valid MOTD string or it is NULL. The trapdoor prevents the function from taking the time to open/read/close the motd.txt file every time someone connects. The problem with this technique is that if you change the MOTD file you must restart the server to get it to read it again and update the cache.
Add a motd.txt file to your server's mod folder and enjoy your center-printed MOTD.
Today I decided to clean it up a bit, make it a callable function and publish it for use by other mod developers who might be interested in using a MOTD in their mod. I don't know where the original code came from, it was a part of LOX from a very long time ago and also exists in WODX and presumably WOD from where LOX and WODX derive their pedigree.
ClientBeginDeathmatch isn't called frequently so there is no advantage to writing the code in-line and avoiding a function call. It also goes against discipline to write something in line where a function will be more advantageous and the resulting code much more clear.
The ClientPrintMOTD function prototype belongs at the top of p_client.c or in g_local.h if you intend to access it globally:
void ClientPrintMOTD (edict_t *ent);
The function body belongs in p_client.c:
Code: [Select]
// Store the message of the day in memory.
char *gMOTD = ((char *)-1); // initialized at startup as bad pointer
cvar_t *motdfile;
void ClientPrintMOTD (edict_t *ent)
{
FILE *in;
char motdPath[MAX_QPATH + 1];
int c;
int motdBytes;
char *here;
// If the MOTD hasn't been loaded, do so.
if (gMOTD == ((char *)-1))
{
// Generate the path to the MOTD file.
if (gamedir == NULL || motdfile == NULL
|| !gamedir->string[0] || !motdfile->string[0])
{
gMOTD = NULL; // null pointer means we'll never try again
return;
}
sprintf (motdPath, "./%s/%s", gamedir->string, motdfile->string);
// Open the file.
in = fopen (motdPath, "rt");
if (in == NULL)
{
gi.dprintf("Opening MOTD file failed, error: %i.\n", errno);
gMOTD = NULL;
return;
}
// Count the number of bytes in the file.
motdBytes = 0;
while ((c = fgetc (in)), c != EOF)
motdBytes++;
// Make space for that many bytes.
gMOTD = gi.TagMalloc (motdBytes + 1, TAG_GAME);
gi.dprintf("Allocating %i bytes for MOTD\n", motdBytes +1);
// Now read the MOTD in for real. Null-terminate the string.
fclose (in);
in = fopen (motdPath, "rt");
here = gMOTD; //extra pointer for writing into gMOTD
while ((c = fgetc (in)), c != EOF)
{
*here = c;
here++;
motdBytes--;
}
*here = '\0';
// If anything went wrong, warn the console.
if (motdBytes != 0)
gi.dprintf ("MOTD error: off by %d bytes", motdBytes);
}
if (gMOTD != NULL) // If a MOTD was successfully loaded, print it.
gi.centerprintf (ent, "%s", gMOTD);
return;
}
Define the necessary CVAR in GameInit:
Code: [Select]
motdfile = gi.cvar ("motdfile", "motd.txt", 0);
Add the CVAR to g_local.h:
Code: [Select]
extern cvar_t *motdfile;
Restore the ClientBeginDeathmatch to it's original beauty.
Code: [Select]
/*=====================
ClientBeginDeathmatch
A client has just connected to the server in deathmatch
mode, so clear everything out before starting them.
=====================*/
void ClientBeginDeathmatch (edict_t *ent)
{
G_InitEdict (ent);
InitClientResp (ent->client);
// locate ent at a spawn point
PutClientInServer (ent);
if (level.intermissiontime)
MoveClientToIntermission (ent);
else
{
// send effect
gi.WriteByte (svc_muzzleflash);
gi.WriteShort (ent-g_edicts);
gi.WriteByte (MZ_LOGIN);
gi.multicast (ent->s.origin, MULTICAST_PVS);
gi.bprintf (PRINT_HIGH, "%s entered the game\n", ent->client->pers.netname);
}
ClientPrintMOTD(ent);
// make sure all view stuff is valid
ClientEndServerFrame (ent);
return;
}
You will notice the ClientPrintMOTD function has a trapdoor in the gMOTD pointer. It's initialized at definition to -1 and the function sets it to NULL if there's a problem initializing the cache it is supposed point to that contains the MOTD text. I'm not sure I would have done it exactly that way but you may see a modified version later, I decided to publish this as-is and may polish it up another time. The trapdoor closes the first time the function is called and the gMOTD pointer either points to a valid MOTD string or it is NULL. The trapdoor prevents the function from taking the time to open/read/close the motd.txt file every time someone connects. The problem with this technique is that if you change the MOTD file you must restart the server to get it to read it again and update the cache.
Add a motd.txt file to your server's mod folder and enjoy your center-printed MOTD.
.. my mistake. disregard that. so now that's out of the way, you can concentrate on his issue. 
I didn't pay close enough attention to the threading. I hate web forums for that reason. One of these days someone is going to invent a way for web forums to display threaded posts. 
