Lerp between two values - Node.js Number

Description

Lerp between two values
Demo Code

/** @namespace LAB*/
LAB = LAB || {};// ww  w  . j  a  va 2 s . c o m

/********************************************
  MATH
********************************************/

/**
 @function
 */
LAB.random       = function( _min, _max){
   return Math.random() * ( _max - _min ) + _min;
}
/**
 @function
 */
LAB.randomInt      = function( _min, _max) {
   return Math.floor( LAB.random( _min, _max ));
}
/**
 @function
 */
LAB.randomObject    = function( _array ){
   return _array[ Math.min(LAB.randomInt(0, _array.length ), _array.length-1)];
}

/**
 @function
 */
LAB.map        = function(value, _oldMin, _oldMax, _min, _max){    
   return _min + ((value-_oldMin)/(_oldMax-_oldMin)) * (_max-_min);
}

/**
 * Lerp between two values
 * @param {Float} start   Start value
 * @param {Float} stop     End value
 * @param {Float} amount   Where between values we're at (0-1.0)
 * @return {Float}        Lerped value
 */
LAB.lerp      = function(start, stop, amt) {
  return start + (stop-start) * amt;
}

/**
 * Lerp values of two objects. Note: will return an object with same props as start; if stop 
 * Object does not have a value, it will return start value. 
 * e.g. LAB.lerpObject( {x:0,y:15}, {x:50}, .5 ) returns {x:25,y:15} 
 * @param {Float} start   Start value
 * @param {Float} stop     End value
 * @param {Float} amount   Where between values we're at (0-1.0)
 * @return {Float}        Lerped value
 */
LAB.lerpObjects    = function(start,stop,amt) {
  var returnObj = {};
  for ( var prop in start ){
    if ( stop.hasOwnProperty(prop) ){
      returnObj[prop] = LAB.lerp( start[prop], stop[prop], amt );
    } else {
      returnObj[prop] = start[prop];
    }
  }
  return returnObj;
}

/**
 @function
 */
LAB.clamp       = function( value, _min, _max ){
   return Math.min( Math.max( value, _min), _max );
}

/**
 @function
 */
LAB.degToRad    = function( deg ){
   return deg * 0.0174532925;
}
/**
 @function
 */
LAB.radToDeg    = function( rad ){
   return rad * 57.2957795;
}

/**
 * @returns The sign of this number, 0 if the number is 0.
 * example: aNumber.x.sign();
 */
Number.prototype.sign = function() {
  if(this > 0) {
    return 1;
  } else if (this < 0) {
    return -1;
  } else {
    return 0;
  }
}

/********************************************
  LOGGING
********************************************/

/** @type {Number} */
LAB.DEBUG     = 0;

/** @type {Number} */
LAB.WARNING    = 1;

/** @type {Number} */
LAB.ERROR     = 2;

/** @type {Number} */
LAB.FATAL_ERROR  = 3;

/**
 * Global LAB log level 
 * @type {Number} 
*/
LAB.logLevel = LAB.WARNING;

/**
 * Set LAB.logLevel
 * @param {Integer} logLevel
 */
LAB.setLogLevel   = function( logLevel ){
  if ( logLevel > LAB.FATAL_ERROR ) logLevel = LAB.FATAL_ERROR;
  if ( logLevel < LAB.DEBUG ) logLevel = LAB.DEBUG;
  LAB.logLevel = logLevel;
}

/**
 * Simple wrapper for console.log /  window.dump. Will only log if level is greater
 * than or equal to current level
 * @param  {String}   text 
 * @param  {Integer}   level (optional) LAB log level (defaults to LOG.DEBUG)
 */
LAB.log        = function( text, level ) {
  level = (level == null ? LAB.DEBUG : level);
  if ( LAB.logLevel > level ) return;

  if (window.console && window.console.log) {
    window.console.log( text );
  } else if (window.dump) {
    window.dump( text );
  }
}

/********************************************
  ANIMATION
********************************************/

  //http://paulirish.com/2011/requestanimationframe-for-smart-animating/
  /** 
    @function 
    @public
  */
  if ( !window.requestAnimationFrame ) {

    window.requestAnimationFrame = ( function() {

      return window.webkitRequestAnimationFrame ||
      window.mozRequestAnimationFrame ||
      window.oRequestAnimationFrame ||
      window.msRequestAnimationFrame ||
      function( /* function FrameRequestCallback */ callback, /* DOMElement Element */ element ) {

        window.setTimeout( callback, 1000 / 60 );

      };

    } )();
  }
  
  // TO DO: window.cancelAnimationFrame

/********************************************
  BROWSER UTILS
********************************************/
  
  /**
   * get string from url. e.g. www.lab.com/index.html?sandwich=turkey returns 'turkey'
   * @param  {String} key      Query param (not including ? or &)
   * @param  {String} default_ (Optional) what to return if param not found
   * @return {String}          Returns value of key or default
   */
  LAB.getQueryString = function(key, default_)
  {
    if (default_==null) default_=""; 
    key = key.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
    var regex = new RegExp("[\\?&]"+key+"=([^&#]*)");
    var qs = regex.exec(window.location.href);
    if(qs == null)
      return default_;
    else
      return qs[1];
  }

/********************************************
  GENERIC UTILS
********************************************/

  LAB.alphabet = LAB.alphabet || ['#','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'];  

/********************************************
  COMPATIBILITY
********************************************/

  // add bind method for browsers that don't currently support it (such as Safari)
  if (!Function.prototype.bind) {  
    Function.prototype.bind = function (oThis) {  
    if (typeof this !== "function") {  
      // closest thing possible to the ECMAScript 5 internal IsCallable function  
      throw new TypeError("Function.prototype.bind - what is trying to be bound is not callable");  
    }  
    
    var aArgs = Array.prototype.slice.call(arguments, 1),   
      fToBind = this,   
      fNOP = function () {},  
      fBound = function () {  
        return fToBind.apply(this instanceof fNOP  
                   ? this  
                   : oThis || window,  
                   aArgs.concat(Array.prototype.slice.call(arguments)));  
      };  
    
    fNOP.prototype = this.prototype;  
    fBound.prototype = new fNOP();  
    
    return fBound;  
    };  
  } 


/********************************************
  NAMESPACE
********************************************/
/**
 * Use this function to safely create a new namespace
 * if a namespace already exists, it won't be recreated.
 *
 * @function
 * @param {String} nsString The namespace as a string.
 * @return {Object} The namespace object.
 */
window.namespace = function (namespaceString) {
  var parts = namespaceString.split('.'),
    parent = window,
    i;

  for (i=0; i<parts.length; i +=1) {
    // create a property if it doesn't exist
    if (typeof parent[parts[i]] === "undefined") {
      parent[parts[i]] = {};
    }
    parent = parent[parts[i]];
  }
  return parent;
};
Lerp between two values - Node.js Number

Description

Demo Code

Related Tutorials
