[pierhs]

Add this function first:

Код:

forward PlayerToPoint(Float:radi, playerid, Float:x, Float:y, Float:z);
public PlayerToPoint(Float:radi, playerid, Float:x, Float:y, Float:z)
{
  if(IsPlayerConnected(playerid))
	{
		new Float:oldposx, Float:oldposy, Float:oldposz;
		new Float:tempposx, Float:tempposy, Float:tempposz;
		GetPlayerPos(playerid, oldposx, oldposy, oldposz);
		tempposx = (oldposx -x);
		tempposy = (oldposy -y);
		tempposz = (oldposz -z);
		//printf("DEBUG: X:%f Y:%f Z:%f",posx,posy,posz);
		if (((tempposx < radi) && (tempposx > -radi)) && ((tempposy < radi) && (tempposy > -radi)) && ((tempposz < radi) && (tempposz > -radi)))
		{
			return 1;
		}
	}
	return 0;
}

Then change a little your code:

Код:

public isPlayerInArea()
  {
    new Float:X, Float:Y, Float:Z;
    for(new i=0; i < MAX_PLAYERS; i++)
    {
      if (PlayerToPoint(25.0(for example its the cover distance), i, x(the x coord), y(the x coord), z(the z coord)){
        SetPlayerHealth(i, 0);
      }
    }
  }