From Second Life Wiki

Description

This sample script creates a slide lever which will move through a series of positions between two points, every time a user touches it. This script is a part of Haravikk Mistral's Lever Library.

When touched this lever will move in a given direction until it reaches FORWARD_POINT, at which point any subsequent touch will cause it to change direction, moving instead towards BACKWARD_POINT where the same behaviour occurs but in reverse. This will result in a lever which can be moved between these two limits simply by touching it.

You should be wary when setting points when it comes to local and global co-ordinates. It is strongly recommended that you use only levers that are child-prims of something else, so that they may use local co-ordinates which are a lot easier to use. You can get the co-ordinates you require using the llGetLocalPos() function.

This script also contains other features, including the ability to have it reset after a period of time, and also have it contact other objects regarding changes, either using link-messages or by sending messages using whisper/say/shout/region-say. See the comments in the script below for COMMS_TYPE on how to enable these.

Script

// =====================================================================
// Simple Touch Slide Lever by Haravikk Mistral
// =====================================================================
// This script allows you to create a simple lever that when touched 
// will slide through a set of positions. It is best used when the lever 
// prim is a child of a root prim, as the slide is performed between two 
// points.
//
// This script can be used and modified freely, though I ask that you 
// give credit to myself where possible, and provide a link to my 
// wiki page at https://wiki.secondlife.com/wiki/User:Haravikk_Mistral
// =====================================================================
 
// =====================================================================
// CONSTANTS
// =====================================================================
// The following values can be used to quickly set-up a lever without 
// having to modify the script. Read the comments above each item to 
// get an idea of what to do.
 
// The number of lever positions from FORWARD_POINT to BACKWARD_POINT 
// (inclusive). Minimum POSITIONS is 2.
integer POSITIONS       = 3;
// The starting position, positions are numbered from 1 to POSITIONS
integer START_POSITION  = 1;
// The starting direction, TRUE will slide the lever forward from it's 
// starting position, FALSE will slide it backward first. When it 
// reaches it's limit it will change direction.
integer START_DIRECTION = TRUE;
 
// The forward/end-point of the slide lever's movement
vector  FORWARD_POINT   = <-0.15, 0.0, 0.0>;
// The back/start-point of the slide lever's movement
vector  BACKWARD_POINT  = <0.15, 0.0, 0.0>;
 
// A sound to play when moving the lever
key     SOUND           = NULL_KEY;
// The volume of the sound
float   SOUND_VOLUME    = 1.0;
 
// This value determines how long the lever will wait before resetting 
// it's position back to START_POSITION and START_DIRECTION. Set this 
// to 0.0 if you never want to reset the lever.
float   RESET_TIME      = 30.0;
 
// Determines what type of message this lever sends when its position 
// changes. The available types are:
// -1   lever sends no communications (lever is a prop only)
//  0   link-message (see LINK_* constants below to set-up)
//  1   whisper      (see CHANNEL constant)
//  2   say          (see CHANNEL constant)
//  3   shout        (see CHANNEL constant)
//  4   region-say   (see CHANNEL constant)
//
// Link messages will have the position number in their string parameter 
// and the key of the user who touched the lever in the key parameter.
// All other message types will contain a message in the form:
//  <position>,<user>
// That is; the position, and user-key are comma-separated.
// NOTE: Any time the lever positions itself (reset) the key will be 
// NULL_KEY.
integer COMMS_TYPE      = -1;
 
// Determines what channel the lever whispers/says/shouts/region-says on
integer CHANNEL         = -1234567890;
 
// The link in a linked-set to send messages to upon changing position
integer LINK_TARGET     = LINK_ROOT;
// The value to place in the integer parameter of a link-message for 
// easy filtering.
integer LINK_FILTER     = 8192;
 
// =====================================================================
// VARIABLES
// =====================================================================
// Below here are variables, these are used by the script.
integer position        = 0;
integer direction       = START_DIRECTION;
 
float   positionsF      = 0.0;
 
moveToPosition(integer newPosition, key id) {
    if (newPosition > POSITIONS) newPosition = POSITIONS;
    else if (newPosition < 1) newPosition = 1;
 
    integer steps = newPosition - position;
    if (!steps) return; // Already there
 
    integer change = 1;
    if (steps < 0) {
        direction = FALSE;
        change = -1;
        steps = -steps;
    } else direction = TRUE;
 
    integer i = 0;
    vector diff = FORWARD_POINT - BACKWARD_POINT;
 
    do {
        position += change;
        llSetPos(BACKWARD_POINT + (
            diff * ((float)(position - 1) / positionsF))
        );
 
        if (SOUND) llPlaySound(SOUND, SOUND_VOLUME);
    } while ((++i) < steps);
 
    if (COMMS_TYPE >= 0) {
        if (COMMS_TYPE == 0)
            llMessageLinked(LINK_TARGET, LINK_FILTER, (string)position, id);
        else {
            string str = (string)position + "," + (string)id;
 
            if (COMMS_TYPE == 1) llWhisper(CHANNEL, str);
            else if (COMMS_TYPE == 2) llSay(CHANNEL, str);
            else if (COMMS_TYPE == 3) llShout(CHANNEL, str);
            else if (COMMS_TYPE == 4) llRegionSay(CHANNEL, str);
        }
    }
 
    if (RESET_TIME > 0.0) llSetTimerEvent(RESET_TIME);
}
 
default {
    state_entry() {
        positionsF = (float)(POSITIONS - 1);
        moveToPosition(START_POSITION, NULL_KEY);
    }
 
    touch_start(integer x) {
        x = position;
        if (direction) {
            if ((++x) > POSITIONS) 
                x = POSITIONS - 1;
        } else if ((--x) < 1) x = 2;
 
        moveToPosition(x, llDetectedKey(0));
    }
 
    timer() {
        llSetTimerEvent(0.0);
        moveToPosition(START_POSITION, NULL_KEY);
        direction = START_DIRECTION;
    }
}