[(-DR-)GrammerNatzi]

I am trying to work on something for my plug-in, and I need to find out how to find entities (the infected, as I am working in Left 4 Dead) in a radius around an X Y Z coordinate. For example, let's say I wanted to find entities around a bullet impact with a radius of about 300. How would I do this? Is it even possible?

[Greyscale]

If you have the coordinate of the impact, (the event should provide it) its just the distance formula.

sqrt ( (x2-x1)^2 + (y2-y1)^2 + (z1 - z2)^2 )

Or you can just look in vector.inc: GetVectorDistance(vec1, vec2)


Loop through all the entities and check if it's within the given radius:

PHP Code:

new Float:entityloc[3];

new maxentities = GetMaxEntities(); // the highest number of entities on the map.
for (new x = MAXPLAYERS + 1; x <= maxentities; x++)  // start at 65, 1 higher than the max player index.
{
    if (!IsValidEdict(x)) // if the int isn't a valid entity index, then stop
    {
        continue;
    }
    
    GetEntPropVector(x, Prop_Data, "m_vecOrigin", entityloc); // get the coordinate of the entity.

    if (GetVectorDistance(bulletloc, entityloc) <= 300.0) // check if the entity is within 300 units of the entity, if it is then do whatever you needa do.
    {
        // this entity is within 300 units.
    }
} 


Keep in mind this code was written in this little reply-box completely untested for compilation. So it might require some tweaks.

Good luck.

[DaFox]

If your only wanting to find infected your better off using FindEntityByClassname() I think.

Also We should expose the virtual function "EnumerateElementsInSphere()" I would assume thats much faster than the current methods that we have.

[AtomicStryker]

PHP Code:

    new Float:DISTANCESETTING = 300;
    
    new Float:impact[3];    
    impact[0] = GetEventFloat(event,"x");
    impact[1] = GetEventFloat(event,"y");
    impact[2] = GetEventFloat(event,"z");

    
    for (new target = 1; target <= GetMaxClients(); target++)
    {
        if (IsClientInGame(target))
        {
            if (IsPlayerAlive(target) && GetClientTeam(target) == 3)
            {
                new Float:targetVector[3];
                GetClientAbsimpact(target, targetVector);
                
                new Float:distance = GetVectorDistance(targetVector, impact);
                if (distance < DISTANCESETTING)
                    {                            
                    //ACTIONS ON AFFECTED TARGET
                    }
            }
        }
    } 


[DaFox]

@AtomicStryker

You should be using decl instead of new for your arrays, And you should never be creating variables inside a loop like that.

[Greyscale]

Originally Posted by AtomicStryker PHP Code:     new Float:DISTANCESETTING = 300;          new Float:impact[3];         impact[0] = GetEventFloat(event,"x");     impact[1] = GetEventFloat(event,"y");     impact[2] = GetEventFloat(event,"z");          for (new target = 1; target <= GetMaxClients(); target++)     {         if (IsClientInGame(target))         {             if (IsPlayerAlive(target) && GetClientTeam(target) == 3)             {                 new Float:targetVector[3];                 GetClientAbsimpact(target, targetVector);                                  new Float:distance = GetVectorDistance(targetVector, impact);                 if (distance < DISTANCESETTING)                     {                                                 //ACTIONS ON AFFECTED TARGET                     }             }         }     }

I assume this is a typo:

"GetClientAbsimpact" (search replace mistake)

new Float:targetVector[3];

Move this out of the loop so you're not reinitializing it 64 times. And also use 'decl' this is faster as well. The difference between 'decl' and 'new' is that new gives the object an inital value (like 0, false, 0.0, "") while decl just leaves whatever garbage was in memory before, but you plan on overwriting it. This improves performance a little as well.


Don't use GetMaxClients(), use MaxClients. It's a dynamic variable that holds what you need and is quicker than calling a function.

[jeremyvillanueva]

Hi,
"GetClientAbsimpact" should be replaced by GetClientAbsOrigin

Like this,
float DISTANCESETTING = 5;

float impact[3];
float targetVector[3];

int TotalSurvivors=0;

impact[0] = GetEventFloat(event,"x");
impact[1] = GetEventFloat(event,"y");
impact[2] = GetEventFloat(event,"z");
for (int target=1;target<=MaxClients;target++)
{
if (IsClientInGame(target) && GetClientTeam(target) == 2 && IsPlayerAlive(target) && !IsFakeClient(target))
{
GetClientAbsOrigin(target, targetVector);

float distance = GetVectorDistance(targetVector, impact);
if (distance < DISTANCESETTING)
{
//ACTIONS ON AFFECTED TARGET
}
}
}

thanks a lot,