////  move.js////  Created by AndrewMeadows, 2014.09.17////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html////// The avatar can be controlled by setting two motor parameters: motorVelocity and motorTimescale.// Once the motorVelocity is set the avatar will try to move in that direction and speed.  The// motorTimescale is the approximate amount of time it takes for the avatar to reach within 1/e of its// motorVelocity, so a short timescale makes it ramp up fast, and a long timescale makes it slow.  // These parameters control the motor's speed and strength.var MAX_MOTOR_TIMESCALE = 0.5;var PUSHING_MOTOR_TIMESCALE = 0.25;var BRAKING_MOTOR_TIMESCALE = 0.125;var VERY_LONG_TIME = 1000000.0; var AVATAR_SPEED = 4.0;var MIN_BRAKING_SPEED = 0.2;  var motorAccumulator = {x:0.0, y:0.0, z:0.0};var isBraking = false; // There is a bug in Qt-5.3.0 (and below) that prevents QKeyEvent.isAutoRepeat from being correctly set.// This means we can't tell when a held button is actually released -- all we get are the repeated // keyPress- (and keyRelease-) events.  So what we have to do is keep a list of last press timestamps// for buttons of interest, and then periodically scan that list for old timestamps and drop any that// have expired (at which point we actually remove that buttons effect on the motor).  As long as the // check period is longer than the time between key repeats then things will be smooth, and as long// as the expiry time is short enough then the stop won't feel too laggy. var MAX_AUTO_REPEAT_DELAY = 3;var KEY_RELEASE_EXPIRY_MSEC = 100; // KeyInfo class contructor:function KeyInfo(contribution) {    this.motorContribution = contribution; // Vec3 contribution of this key toward motorVelocity    this.releaseTime = new Date(); // time when this button was released    this.pressTime = new Date(); // time when this button was pressed    this.isPressed = false;} // NOTE: the avatar's default orientation is such that "forward" is along the -zAxis, and "left" is along -xAxis.var controlKeys = {     "UP"   : new KeyInfo({x: 0.0, y: 0.0, z:-1.0}),    "DOWN" : new KeyInfo({x: 0.0, y: 0.0, z: 1.0}),    "SHIFT+LEFT" : new KeyInfo({x:-1.0, y: 0.0, z: 0.0}),    "SHIFT+RIGHT": new KeyInfo({x: 1.0, y: 0.0, z: 0.0}),    "w" : new KeyInfo({x: 0.0, y: 0.0, z:-1.0}),    "s" : new KeyInfo({x: 0.0, y: 0.0, z: 1.0}),    "e" : new KeyInfo({x: 0.0, y: 1.0, z: 0.0}),    "c" : new KeyInfo({x: 0.0, y:-1.0, z: 0.0})}; // list of last timestamps when various buttons were last pressedvar pressTimestamps = {}; function keyPressEvent(event) {    // NOTE: we're harvesting some of the same keyboard controls that are used by the default (scriptless)     // avatar control.  The scriptless control can be disabled via the Menu, thereby allowing this script     // to be the ONLY controller of the avatar position.        var keyName = event.text;    if (event.isShifted) {        keyName = "SHIFT+" + keyName;    }      var key = controlKeys[keyName];    if (key != undefined) {        key.pressTime = new Date();        // set the last pressTimestap element to undefined (MUCH faster than removing from the list)        pressTimestamps[keyName] = undefined;        var msec = key.pressTime.valueOf() - key.releaseTime.valueOf();        if (!key.isPressed) {            // add this key's effect to the motorAccumulator            motorAccumulator = Vec3.sum(motorAccumulator, key.motorContribution);            key.isPressed = true;        }    }} function keyReleaseEvent(event) {    var keyName = event.text;    if (event.isShifted) {        keyName = "SHIFT+" + keyName;    }     var key = controlKeys[keyName];    if (key != undefined) {        // add key to pressTimestamps        pressTimestamps[keyName] = new Date();        key.releaseTime = new Date();        var msec = key.releaseTime.valueOf() - key.pressTime.valueOf();    }} function updateMotor(deltaTime) {    // remove expired pressTimestamps    var now = new Date();    for (var keyName in pressTimestamps) {        var t = pressTimestamps[keyName];        if (t != undefined) {            var msec = now.valueOf() - t.valueOf();            if (msec > KEY_RELEASE_EXPIRY_MSEC) {                // the release of this key is now official, and we remove it from the motorAccumulator                motorAccumulator = Vec3.subtract(motorAccumulator, controlKeys[keyName].motorContribution);                controlKeys[keyName].isPressed = false;                // set the last pressTimestap element to undefined (MUCH faster than removing from the list)                pressTimestamps[keyName] = undefined;            }        }    }     var motorVelocity = {x:0.0, y:0.0, z:0.0};     // figure out if we're pushing or braking    var accumulatorLength = Vec3.length(motorAccumulator);    var isPushing = false;    if (accumulatorLength == 0.0) {        if (!isBraking) {            isBraking = true;        }        isPushing = false;    } else {        isPushing = true;        motorVelocity = Vec3.multiply(AVATAR_SPEED / accumulatorLength, motorAccumulator);    }     // compute the timescale    var motorTimescale = MAX_MOTOR_TIMESCALE;    if (isBraking) {        var speed = Vec3.length(MyAvatar.getVelocity());        if (speed < MIN_BRAKING_SPEED) {            // we're going slow enough to turn off braking            // --> we'll drift to a halt, but not so stiffly that we can't be bumped            isBraking = false;            motorTimescale = MAX_MOTOR_TIMESCALE;        } else {            // we're still braking            motorTimescale = BRAKING_MOTOR_TIMESCALE;        }    } else if (isPushing) {        motorTimescale = PUSHING_MOTOR_TIMESCALE;    }     // apply the motor parameters    MyAvatar.motorVelocity = motorVelocity;    MyAvatar.motorTimescale = motorTimescale;} function scriptEnding() {    // disable the motor    MyAvatar.motorVelocity = {x:0.0, y:0.0, z:0.0}    MyAvatar.motorTimescale = VERY_LONG_TIME;}  // init stuffMyAvatar.motorReferenceFrame = "camera"; // "camera" is default, other options are "avatar" and "world"MyAvatar.motorTimescale = VERY_LONG_TIME; // connect callbacksController.keyPressEvent.connect(keyPressEvent);Controller.keyReleaseEvent.connect(keyReleaseEvent);Script.update.connect(updateMotor);Script.scriptEnding.connect(scriptEnding)