[Gryphus One]

Nice tutorial, I have learned some things myself, however I also think you could have made it better:

• Although it's not necessary, you could tag FireShot[MAX_PLAYERS] as a bool so it only accepts two values.
• I'm not sure but I think IsPlayerInAnyVehicle(playerid) works for passengers too, and I guess you don't want passengers to shoot. I would use if GetPlayerState(playerid) == PLAYER_STATE_DRIVER instead.
• Instead of newkeys & 4 I would use newkeys & KEY_FIRE for better readability and because you never know if sa-mp might change its defines someday for some reason.
• Why are you using SetPlayerTime(playerid,0,0) when the laser is fired?
• When you do Float:dist = 50.0 and if(IsPlayerInRangeOfPoint(i, 50.0, x, y, z)) I think it's better that 50.0 be a define at the top of your script, so you can easily change that value if you want.
• Instead of SetTimerEx("ShotFire", 1000, 0, "i", playerid) I think it's better to use GetTickCount() and a variable to store the time. I think with this you wouldn't even need FireShot[MAX_PLAYERS] anymore.
• In your two loops you should use break; after your code is executed so the loop will not continue checking for players.
• EDIT: VERY IMPORTANT!!! If you write a filterscript, you must return a value in your callbacks because otherwise those callbacks won't be called in your gamemode.

So I would script it like this. I have commented those lines of yours that I would remove or replace for others:

pawn Code:

#include <a_samp>

#define LASER_DISTANCE 50 // Added this

//new FireShot[MAX_PLAYERS];
new TimeOfLastShot[MAX_PLAYERS]; // This instead
new gRocketObj[MAX_PLAYERS];

public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)
{
    //if(IsPlayerInAnyVehicle(playerid) && FireShot[playerid] == 0 && newkeys & 4 && !IsValidObject(gRocketObj[playerid]))   // Only run the code if the object doesn't already exist, otherwise more objects will take up gRocketObj and the previous ones won't be deleted
    if( (GetPlayerState(playerid) == PLAYER_STATE_DRIVER) && ( (GetTickCount() - TimeOfLastShot[playerid]) >= 1000 ) && (newkeys & KEY_FIRE) && !IsValidObject(gRocketObj[playerid]) ) // This instead
    {
        SetPlayerTime(playerid,0,0);
        new
            vehicleid = GetPlayerVehicleID(playerid),
            Float:x,
            Float:y,
            Float:z,
            Float:r,
            //Float:dist = 50.0,
            Float:dist = LASER_DISTANCE, // This instead
            Float:tmpang,
            Float:tmpx,
            Float:tmpy,
            Float:tmpz;

        //FireShot[playerid] = 1;
        //SetTimerEx("ShotFire", 1000, 0, "i", playerid);
        TimeOfLastShot[playerid] = GetTickCount(); // This instead
        GetVehiclePos(vehicleid, x, y, z);
        GetVehicleZAngle(vehicleid, r);
        new rand = random(12);
        switch(rand)
        {
            case 0: gRocketObj[playerid] = CreateObject(18647, x, y, z, 0, 0, r);
            case 1: gRocketObj[playerid] = CreateObject(18648, x, y, z, 0, 0, r);
            case 2: gRocketObj[playerid] = CreateObject(18649, x, y, z, 0, 0, r);
            case 3: gRocketObj[playerid] = CreateObject(18650, x, y, z, 0, 0, r);
            case 4: gRocketObj[playerid] = CreateObject(18651, x, y, z, 0, 0, r);
            case 5: gRocketObj[playerid] = CreateObject(18652, x, y, z, 0, 0, r);
            case 6: gRocketObj[playerid] = CreateObject(18647, x, y, z, 0, 0, r+90);
            case 7: gRocketObj[playerid] = CreateObject(18648, x, y, z, 0, 0, r+90);
            case 8: gRocketObj[playerid] = CreateObject(18649, x, y, z, 0, 0, r+90);
            case 9: gRocketObj[playerid] = CreateObject(18650, x, y, z, 0, 0, r+90);
            case 10: gRocketObj[playerid] = CreateObject(18651, x, y, z, 0, 0, r+90);
            case 11: gRocketObj[playerid] = CreateObject(18652, x, y, z, 0, 0, r+90);
        }
        for(new i;i<MAX_PLAYERS;i++)
        {
            if(IsPlayerConnected(i))
            if(i == playerid)continue;
            //if(IsPlayerInRangeOfPoint(i, 50.0, x, y, z))
            if(IsPlayerInRangeOfPoint(i, LASER_DISTANCE, x, y, z)) // This instead
            {
                GetPlayerPos(i, tmpx, tmpy, tmpz);
                tmpang = (90-atan2(tmpy-y, tmpx-x));
                if(tmpang < 0)tmpang = 360.0+tmpang;
                tmpang = 360.0 - tmpang;
                if(floatabs(tmpang-r) < 5.0)
                {
                    dist = GetPlayerDistanceFromPoint(i, x, y, z);
                    break; // Added this
                }
            }
        }
        MoveObject(gRocketObj[playerid],x + (dist * floatsin(-r, degrees)),y + (dist * floatcos(-r, degrees)),z,100.0);                             // Nice and fast!
    }
    return 1; // Added this
}



/*forward ShotFire(playerid);
public ShotFire(playerid)
{
        FireShot[playerid] = 0;
        return 1;
}*/  //Not needed

public OnObjectMoved(objectid)
{
        for(new i;i<MAX_PLAYERS;i++)
        {
                if(objectid == gRocketObj[i])
                {
                    new
                        Float:x,
                        Float:y,
                        Float:z;

                    GetObjectPos(gRocketObj[i], x, y, z);
                    CreateExplosion(x, y, z, 11, 3.0);
                    DestroyObject(gRocketObj[i]);
                    break; // Added this
                }
        }
        return 1; // Added this
}