DEV/flutter_flutter
1
0
Fork 0
mirror of https://github.com/flutter/flutter.git synced 2026-02-20 02:29:02 +08:00
Code Issues Packages Projects Releases Wiki Activity

Adds bounce and elastic easing to animation curves

Browse Source
This commit is contained in:
Viktor Lidholt 2015-08-17 17:07:30 -07:00
parent 173a33ae6e
commit 92baad7424
1 changed files with 86 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

86
sky/packages/sky/lib/animation/curves.dart
View File

@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:math' as math;
double _evaluateCubic(double a, double b, double m) {
// TODO(abarth): Would Math.pow be faster?
return 3 * a * (1 - m) * (1 - m) * m + 3 * b * (1 - m) * m * m + m * m * m;
@ -79,6 +81,84 @@ class Cubic implements Curve {
}
}
double _bounce(double t)
{
if (t < 1.0 / 2.75) {
return 7.5625 * t * t;
} else if (t < 2 / 2.75) {
t -= 1.5 / 2.75;
return 7.5625 * t * t + 0.75;
} else if (t < 2.5 / 2.75) {
t -= 2.25 / 2.75;
return 7.5625 * t * t + 0.9375;
}
t -= 2.625 / 2.75;
return 7.5625 * t * t + 0.984375;
}
class BounceInCurve implements Curve {
const BounceInCurve();
double transform(double t) {
return 1.0 - _bounce(1.0 - t);
}
}
class BounceOutCurve implements Curve {
const BounceOutCurve();
double transform(double t) {
return _bounce(t);
}
}
class BounceInOutCurve implements Curve {
const BounceInOutCurve();
double transform(double t) {
if (t < 0.5)
return (1.0 - _bounce(1.0 - t)) * 0.5;
else
return _bounce(t * 2.0 - 1.0) * 0.5 + 0.5;
}
}
class ElasticInCurve implements Curve {
const ElasticInCurve([this.period = 0.4]);
final double period;
double transform(double t) {
double s = period / 4.0;
t = t - 1.0;
return -math.pow(2.0, 10.0 * t) * math.sin((t - s) * (math.PI * 2.0) / period);
}
}
class ElasticOutCurve implements Curve {
const ElasticOutCurve([this.period = 0.4]);
final double period;
double transform(double t) {
double s = period / 4.0;
return math.pow(2.0, -10 * t) * math.sin((t - s) * (math.PI * 2.0) / period) + 1.0;
}
}
class ElasticInOutCurve implements Curve {
const ElasticInOutCurve([this.period = 0.4]);
final double period;
double transform(double t) {
t = t * 2;
double s = period / 4.0;
t = t - 1.0;
if (t < 0.0)
return -0.5 * math.pow(2.0, 10.0 * t) * math.sin((t - s) * (math.PI * 2.0) / period);
else
return math.pow(2.0, -10.0 * t) * math.sin((t - s) * (math.PI * 2.0) / period) * 0.5 + 1.0;
}
}
const Linear linear = const Linear();
const Cubic ease = const Cubic(0.25, 0.1, 0.25, 1.0);
const Cubic easeIn = const Cubic(0.42, 0.0, 1.0, 1.0);
@ -86,3 +166,9 @@ const Cubic easeOut = const Cubic(0.0, 0.0, 0.58, 1.0);
const Cubic easeInOut = const Cubic(0.42, 0.0, 0.58, 1.0);
const ParabolicRise parabolicRise = const ParabolicRise();
const ParabolicFall parabolicFall = const ParabolicFall();
const BounceInCurve bounceIn = const BounceInCurve();
const BounceOutCurve bounceOut = const BounceOutCurve();
const BounceInOutCurve bounceInOut = const BounceInOutCurve();
const ElasticInCurve elasticIn = const ElasticInCurve();
const ElasticOutCurve elasticOut = const ElasticOutCurve();
const ElasticInOutCurve elasticInOut = const ElasticInOutCurve();