Temporary Rezzer

// =====================================================================
//  Temporary Rezzer  ·  step 1 of 2
//  skimi3d script library
//  https://grid.skimi3d.com/scripts/temporary-rezzer
//
//  Puts something out, and takes it away again. The demo house at a
//  stall, the marquee for tonight only, the target on a shooting range,
//  the maze that rebuilds itself.
//
//  It needs the other half. What it rezzes must contain "Vanisher", the
//  second script in this kit, or it will sit there for ever: nothing
//  can delete an object from outside it, so the thing being rezzed has
//  to be willing to go.
//
//  Plain LSL.
// =====================================================================


// ---------------------------------------------------------------------
//  Settings
// ---------------------------------------------------------------------

// What to rez, by name, out of this prim's Contents. Left empty it uses
// the first object it finds.
string WHAT = "";

// Where it appears, as metres from this prim, along the region's axes:
// X east, Y north, Z up. It cannot be more than ten metres away; that
// is the platform's limit, not this script's.
vector WHERE = <0.0, 2.0, 0.0>;

// Minutes before it is called back. 0.0 means it stays until somebody
// touches the rezzer again.
float MINUTES = 10.0;

// Floating words above the rezzer. Empty for none.
string LABEL = "Touch to put one out";
vector LABEL_COLOUR = <1.0, 1.0, 1.0>;

// Only one at a time: touching again calls the old one back before
// putting a new one out. With this off, every touch adds another, which
// is how a stall ends up with forty houses on it.
integer ONE_AT_A_TIME = TRUE;

// Who may use it. 0 = everyone, 1 = only the owner, 2 = same group.
integer WHO_MAY_USE = 1;


// ---------------------------------------------------------------------
//  Everything below here is the machinery
// ---------------------------------------------------------------------

// The word the rezzer says and the Vanisher listens for. Both halves of
// the kit have to agree on this number and this word. Change them
// together or not at all.
integer CHANNEL = -70714;
string  GO_AWAY = "vanish";

integer gOut = FALSE;


string findObject()
{
    if (WHAT != "") return WHAT;

    if (llGetInventoryNumber(INVENTORY_OBJECT) > 0)
    {
        return llGetInventoryName(INVENTORY_OBJECT, 0);
    }

    return "";
}


callBack()
{
    // Said to the whole region rather than to one object, on a channel
    // nobody types on. That way it reaches whatever is out there even
    // if the rezzer has forgotten it, which is what happens after a
    // region restart.
    llRegionSay(CHANNEL, GO_AWAY);
    gOut = FALSE;
    llSetTimerEvent(0.0);
}


putOut()
{
    string what = findObject();

    if (what == "")
    {
        llOwnerSay("I have no object in my Contents to put out.");
        return;
    }

    if (llGetInventoryType(what) != INVENTORY_OBJECT)
    {
        llOwnerSay("There is no object called \"" + what + "\" in my Contents.");
        return;
    }

    if (llVecMag(WHERE) > 10.0)
    {
        llOwnerSay("WHERE is more than ten metres away, and nothing can be rezzed further than that. Move me closer to where it should stand.");
        return;
    }

    llRezObject(llGetPos() + WHERE, ZERO_VECTOR, ZERO_VECTOR, llGetRot(), 0);
    gOut = TRUE;

    if (MINUTES > 0.0) llSetTimerEvent(MINUTES * 60.0);
}


integer mayUse(key who)
{
    if (WHO_MAY_USE == 1) return who == llGetOwner();
    if (WHO_MAY_USE == 2) return llSameGroup(who);
    return TRUE;
}


default
{
    state_entry()
    {
        llSetText(LABEL, LABEL_COLOUR, 1.0);

        // Anything left standing from before this script started is
        // not ours to keep track of, so it is sent away first.
        callBack();
    }

    touch_start(integer total)
    {
        key who = llDetectedKey(0);

        if (!mayUse(who))
        {
            llRegionSayTo(who, 0, "This one is not yours to use.");
            return;
        }

        if (gOut && ONE_AT_A_TIME)
        {
            callBack();
            return;
        }

        putOut();
    }

    timer()
    {
        callBack();
    }

    on_rez(integer start)
    {
        llResetScript();
    }
}