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// Copyright 2006 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//      http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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 * @fileoverview Easing functions for animations.
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 *
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 * @author [email protected] (Erik Arvidsson)
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 */
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goog.provide('goog.fx.easing');
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/**
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 * Ease in - Start slow and speed up.
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 * @param {number} t Input between 0 and 1.
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 * @return {number} Output between 0 and 1.
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 */
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goog.fx.easing.easeIn = function(t) {
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  return goog.fx.easing.easeInInternal_(t, 3);
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};
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/**
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 * Ease in with specifiable exponent.
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 * @param {number} t Input between 0 and 1.
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 * @param {number} exp Ease exponent.
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 * @return {number} Output between 0 and 1.
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 * @private
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 */
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goog.fx.easing.easeInInternal_ = function(t, exp) {
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  return Math.pow(t, exp);
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};
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/**
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 * Ease out - Start fastest and slows to a stop.
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 * @param {number} t Input between 0 and 1.
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 * @return {number} Output between 0 and 1.
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 */
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goog.fx.easing.easeOut = function(t) {
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  return goog.fx.easing.easeOutInternal_(t, 3);
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};
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/**
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 * Ease out with specifiable exponent.
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 * @param {number} t Input between 0 and 1.
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 * @param {number} exp Ease exponent.
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 * @return {number} Output between 0 and 1.
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 * @private
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 */
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goog.fx.easing.easeOutInternal_ = function(t, exp) {
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  return 1 - goog.fx.easing.easeInInternal_(1 - t, exp);
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};
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/**
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 * Ease out long - Start fastest and slows to a stop with a long ease.
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 * @param {number} t Input between 0 and 1.
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 * @return {number} Output between 0 and 1.
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 */
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goog.fx.easing.easeOutLong = function(t) {
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  return goog.fx.easing.easeOutInternal_(t, 4);
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};
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/**
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 * Ease in and out - Start slow, speed up, then slow down.
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 * @param {number} t Input between 0 and 1.
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 * @return {number} Output between 0 and 1.
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 */
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goog.fx.easing.inAndOut = function(t) {
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  return 3 * t * t - 2 * t * t * t;
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};
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