/**
* Wire
* Copyright (C) 2016 Wire Swiss GmbH
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* This part of the Wire sofware is based on the work of Robert Penner.
* (http://robertpenner.com/easing)
*
* Copyright (C) 2001 Robert Penner
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* Neither the name of the author nor the names of contributors may
* be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package com.waz.zclient.ui.animation.interpolators.penner;
import android.view.animation.Interpolator;
import com.waz.zclient.ui.utils.MathUtils;
public final class Elastic {
private static final float DEFAULT_AMPLITUDE = 1f;
private static final float DEFAULT_PERIOD = .3f;
private Elastic() {}
public static class EaseIn implements Interpolator {
private final float a;
private final float p;
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing in: accelerating from zero velocity.
*/
public EaseIn() {
this(DEFAULT_AMPLITUDE, DEFAULT_PERIOD);
}
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing in: accelerating from zero velocity.
*
* @param a Amplitude.
* @param p Period.
*/
public EaseIn(float a, float p) {
this.a = a;
this.p = p;
}
@Override
public float getInterpolation(float t) {
if (MathUtils.floatEqual(t, 0f)) {
return 0;
}
if (MathUtils.floatEqual(t, 1f)) {
return 1;
}
float s;
float a1 = this.a;
if (a1 < 1) {
a1 = 1;
s = p / 4;
} else {
s = p / (2 * (float) Math.PI) * (float) Math.asin(1f / a1);
}
return -(a1 * (float) Math.pow(2, 10 * (t -= 1)) * (float) Math.sin((t - s) * (2 * Math.PI) / p));
}
}
public static class EaseOut implements Interpolator {
private final float a;
private final float p;
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing out: decelerating from zero velocity.
*/
public EaseOut() {
this(DEFAULT_AMPLITUDE, DEFAULT_PERIOD);
}
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing out: decelerating from zero velocity.
*
* @param a Amplitude.
* @param p Period.
*/
public EaseOut(float a, float p) {
this.a = a;
this.p = p;
}
@Override
public float getInterpolation(float t) {
if (MathUtils.floatEqual(t, 0f)) {
return 0;
}
if (MathUtils.floatEqual(t, 1f)) {
return 1;
}
float s;
float a1 = this.a;
if (a1 < 1) {
a1 = 1;
s = p / 4;
} else {
s = p / (2 * (float) Math.PI) * (float) Math.asin(1f / a1);
}
return (a1 * (float) Math.pow(2, -10 * t) * (float) Math.sin((t - s) * (2 * (float) Math.PI) / p) + 1);
}
}
public static class EaseInOut implements Interpolator {
private final float a;
private final float p;
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing in/out: acceleration until halfway, then deceleration.
*/
public EaseInOut() {
this(DEFAULT_AMPLITUDE, DEFAULT_PERIOD);
}
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing in/out: acceleration until halfway, then deceleration.
*
* @param a Amplitude.
* @param p Period.
*/
public EaseInOut(float a, float p) {
this.a = a;
this.p = p;
}
@Override
public float getInterpolation(float t) {
if (MathUtils.floatEqual(t, 0f)) {
return 0;
}
if (MathUtils.floatEqual(t /= .5f, 2f)) {
return 1;
}
float s;
float a1 = this.a;
if (a1 < 1) {
a1 = 1;
s = p / 4;
} else {
s = p / (2 * (float) Math.PI) * (float) Math.asin(1f / a1);
}
if (t < 1) {
return -.5f * (a1 * (float) Math.pow(2,
10 * (t -= 1)) * (float) Math.sin((t - s) * (2 * (float) Math.PI) / p));
}
return a1 * (float) Math.pow(2,
-10 * (t -= 1)) * (float) Math.sin((t - s) * (2 * (float) Math.PI) / p) * .5f + 1;
}
}
public static class EaseOutIn implements Interpolator {
private final float a;
private final float p;
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing out/in: deceleration until halfway, then acceleration.
*/
public EaseOutIn() {
this(DEFAULT_AMPLITUDE, DEFAULT_PERIOD);
}
/**
* Easing equation function for an elastic (exponentially decaying sine wave)
* easing out/in: deceleration until halfway, then acceleration.
*
* @param a Amplitude.
* @param p Period.
*/
public EaseOutIn(float a, float p) {
this.a = a;
this.p = p;
}
@Override
public float getInterpolation(float t) {
float t1 = t * 2;
float a1 = a;
if (t < .5f) {
if (MathUtils.floatEqual(t1, 0f)) {
return 0;
}
if (MathUtils.floatEqual(t1, 1f)) {
return 1 / 2;
}
float s;
if (a1 < .5f) {
a1 = .5f;
s = p / 4;
} else {
s = p / (2 * (float) Math.PI) * (float) Math.asin(.5f / a1);
}
return (a1 * (float) Math.pow(2,
-10 * t1) * (float) Math.sin((t1 - s) * (2 * (float) Math.PI) / p) + .5f);
} else {
t1 -= 1;
if (MathUtils.floatEqual(t1, 0f)) {
return 1 / 2;
}
if (MathUtils.floatEqual(t1, 1f)) {
return 1 / 2 + .5f;
}
float s;
if (a1 < .5f) {
a1 = .5f;
s = p / 4;
} else {
s = p / (2 * (float) Math.PI) * (float) Math.asin(.5f / a1);
}
return -(a1 * (float) Math.pow(2,
10 * (t1 -= 1)) * (float) Math.sin((t1 - s) * (2 * Math.PI) / p)) + 1 / 2;
}
}
}
}