Cooperative Play.. Cooperative? tutorial

[page=Introduction]
Weapons, weapons, weapons. What's with all the ultraviolence? Let's look forward and try something that might be useful for cooperative play.

If I had to guess, I would think Quake2 co-op play will be a lot like Quake.. Darn it, it's just not cool. This time you're in a platoon and you will exit as such!

Here's what we'll do. When a player attempts to trigger the exit, we'll only allow it when all the players are near the exit. We're going to add a new console variable (cvar) called coopexit to control this behavior, sort of like a deathmatch flag.

[page=Cvar]

Here we go!

Find these in g_local.h:

extern  cvar_t  *sv_cheats;
 extern  cvar_t  *maxclients;

Let's add these:

// Paril - New console variable
extern  cvar_t  *coopexit;

Now, to g_main.c, near the beginning, find:

cvar_t  *sv_cheats;

Add:

// Paril - Added this
cvar_t  *coopexit;

Now, in g_save.c, find

bob_pitch = gi.cvar ("bob_pitch", "0.002", 0);
  bob_roll = gi.cvar ("bob_roll", "0.002", 0);

Add this:

//Paril: New console variable
 coopexit = gi.cvar("coopexit", "0", CVAR_SERVERINFO|CVAR_LATCH);

To g_targets.c!

[page=The Target]

Find:

void use_target_changelevel (edict_t *self, edict_t *other, edict_t *activator)
{

We're changing the beginning to this:

void use_target_changelevel (edict_t *self, edict_t *other, edict_t *activator)
 {
 // Paril: A few local variables for coopexit
 float   radius;
 edict_t *ent = NULL;
 int            i;
 vec3_t  v;

  if (level.intermissiontime)
         return;        // allready activated

 // Paril: If coopexit is on, only exit when all players are at exit
 if (coopexit->value)
 {
        radius = level.players * 100;
        for (i=0&#59; ivalue&#59; i++)
        {
                ent = g_edicts + 1 + i;
                if (!ent->inuse || !ent->client)
                        continue;
                VectorSubtract(activator->s.origin, ent->s.origin, v);
                if (VectorLength(v) > radius)
                        return;
        }
 }

If coopexit is set, we determine an 'exit radius' according to the number of players and then run through the players with the for loop. For the active players, we check their distance from the exit activator and, if we find one that's outside the radius, we return without letting them exit!