tweenjs · alphabetabc · Sep 11, 2025
diff --git a/dist/tween.amd.js b/dist/tween.amd.js
@@ -769,7 +769,7 @@ define(['exports'], (function (exports) { 'use strict';
                 }
                 this._onEveryStartCallbackFired = true;
             }
-            var elapsedTime = time - this._startTime;
+            var elapsedTime = this._yoyo ? Math.min(time - this._startTime, this._duration) : time - this._startTime;
             var durationAndDelay = this._duration + ((_a = this._repeatDelayTime) !== null && _a !== void 0 ? _a : this._delayTime);
             var totalTime = this._duration + this._repeat * durationAndDelay;
             var calculateElapsedPortion = function () {
@@ -894,7 +894,7 @@ define(['exports'], (function (exports) { 'use strict';
         return Tween;
     }());
 
-    var VERSION = '25.0.0';
+    var VERSION = '25.0.1';
 
     /**
      * Tween.js - Licensed under the MIT license

diff --git a/dist/tween.cjs b/dist/tween.cjs
@@ -771,7 +771,7 @@ var Tween = /** @class */ (function () {
             }
             this._onEveryStartCallbackFired = true;
         }
-        var elapsedTime = time - this._startTime;
+        var elapsedTime = this._yoyo ? Math.min(time - this._startTime, this._duration) : time - this._startTime;
         var durationAndDelay = this._duration + ((_a = this._repeatDelayTime) !== null && _a !== void 0 ? _a : this._delayTime);
         var totalTime = this._duration + this._repeat * durationAndDelay;
         var calculateElapsedPortion = function () {
@@ -896,7 +896,7 @@ var Tween = /** @class */ (function () {
     return Tween;
 }());
 
-var VERSION = '25.0.0';
+var VERSION = '25.0.1';
 
 /**
  * Tween.js - Licensed under the MIT license

diff --git a/dist/tween.d.ts b/dist/tween.d.ts
@@ -196,7 +196,7 @@ declare class Sequence {
     static nextId(): number;
 }
 
-declare const VERSION = "25.0.0";
+declare const VERSION = "25.0.1";
 
 declare const nextId: typeof Sequence.nextId;
 /**

diff --git a/dist/tween.esm.js b/dist/tween.esm.js
@@ -767,7 +767,7 @@ var Tween = /** @class */ (function () {
             }
             this._onEveryStartCallbackFired = true;
         }
-        var elapsedTime = time - this._startTime;
+        var elapsedTime = this._yoyo ? Math.min(time - this._startTime, this._duration) : time - this._startTime;
         var durationAndDelay = this._duration + ((_a = this._repeatDelayTime) !== null && _a !== void 0 ? _a : this._delayTime);
         var totalTime = this._duration + this._repeat * durationAndDelay;
         var calculateElapsedPortion = function () {
@@ -892,7 +892,7 @@ var Tween = /** @class */ (function () {
     return Tween;
 }());
 
-var VERSION = '25.0.0';
+var VERSION = '25.0.1';
 
 /**
  * Tween.js - Licensed under the MIT license

diff --git a/dist/tween.umd.js b/dist/tween.umd.js
@@ -773,7 +773,7 @@
                 }
                 this._onEveryStartCallbackFired = true;
             }
-            var elapsedTime = time - this._startTime;
+            var elapsedTime = this._yoyo ? Math.min(time - this._startTime, this._duration) : time - this._startTime;
             var durationAndDelay = this._duration + ((_a = this._repeatDelayTime) !== null && _a !== void 0 ? _a : this._delayTime);
             var totalTime = this._duration + this._repeat * durationAndDelay;
             var calculateElapsedPortion = function () {
@@ -898,7 +898,7 @@
         return Tween;
     }());
 
-    var VERSION = '25.0.0';
+    var VERSION = '25.0.1';
 
     /**
      * Tween.js - Licensed under the MIT license

diff --git a/examples/10_yoyo.html b/examples/10_yoyo.html
@@ -37,6 +37,9 @@ <h2>10 _ yoyo</h2>
 			<div id="target4" data-rotation="0" data-y="0" class="box" style="left: 600px; top: 0px">
 				yoyo with repeat forever, relative values
 			</div>
+			<div id="target5" data-rotation="0" data-y="0" class="box" style="left: 800px; top: 0px">
+				yoyo with repeat forever, relative values, without delay
+			</div>
 		</div>
 
 		<style type="text/css">
@@ -67,6 +70,9 @@ <h2>10 _ yoyo</h2>
 			#target4 {
 				background: skyblue;
 			}
+			#target5 {
+				background: rgb(1, 177, 246);
+			}
 		</style>
 	</body>
 </html>
diff --git a/examples/10_yoyo.js b/examples/10_yoyo.js
@@ -5,86 +5,101 @@ const group = new Group()
 
 animate()
 
+const tweenMap = new Map()
+
 const target1 = document.getElementById('target1')
-const tween1 = new Tween(target1.dataset, group)
-	.to({rotation: 360, y: 300}, 750)
-	.repeat(1)
-	.delay(1000)
-	.yoyo(true)
-	.easing(Easing.Cubic.InOut)
-	.onUpdate(function (object) {
-		updateBox(target1, object)
-	})
-	.start()
+tweenMap.set(
+	'tween1',
+	new Tween(target1.dataset, group)
+		.to({rotation: 360, y: 300}, 750)
+		.repeat(Infinity)
+		.delay(1000)
+		.yoyo(true)
+		.easing(Easing.Quadratic.InOut)
+		.onUpdate(function (object) {
+			updateBox(target1, object)
+		})
+		.start(),
+)
 const target2 = document.getElementById('target2')
-const tween2 = new Tween(target2.dataset, group)
-	.to({rotation: 360, y: 300}, 750)
-	.repeat(Infinity)
-	.delay(1000)
-	.yoyo(true)
-	.easing(Easing.Cubic.InOut)
-	.onUpdate(function (object) {
-		updateBox(target2, object)
-	})
-	.start()
+
+tweenMap.set(
+	'tween2',
+	new Tween(target2.dataset, group)
+		.to({rotation: 360, y: 300}, 750)
+		.repeat(Infinity)
+		.delay(1000)
+		.yoyo(true)
+		.easing(Easing.Cubic.InOut)
+		.onUpdate(function (object) {
+			updateBox(target2, object)
+		})
+		.start(),
+)
 const target3 = document.getElementById('target3')
-const tween3 = new Tween(target3.dataset, group)
-	.to({rotation: '+360', y: '+300'}, 750)
-	.repeat(1)
-	.delay(1000)
-	.yoyo(true)
-	.easing(Easing.Cubic.InOut)
-	.onUpdate(function (object) {
-		updateBox(target3, object)
-	})
-	.start()
+tweenMap.set(
+	'tween3',
+	new Tween(target3.dataset, group)
+		.to({rotation: '+360', y: '+300'}, 750)
+		.repeat(1)
+		.delay(1000)
+		.yoyo(true)
+		.easing(Easing.Cubic.InOut)
+		.onUpdate(function (object) {
+			updateBox(target3, object)
+		})
+		.start(),
+)
 const target4 = document.getElementById('target4')
-const tween4 = new Tween(target4.dataset, group)
-	.to({rotation: '+360', y: '+300'}, 750)
-	.repeat(Infinity)
-	.delay(1000)
-	.yoyo(true)
-	.easing(Easing.Cubic.InOut)
-	.onUpdate(function (object) {
-		updateBox(target4, object)
-	})
-	.start()
+tweenMap.set(
+	'tween4',
+	new Tween(target4.dataset, group)
+		.to({rotation: '+360', y: '+300'}, 750)
+		.repeat(Infinity)
+		.delay(1000)
+		.yoyo(true)
+		.easing(Easing.Quadratic.InOut)
+		.onUpdate(function (object) {
+			updateBox(target4, object)
+		})
+		.start(),
+)
+
+const target5 = document.getElementById('target5')
+tweenMap.set(
+	'tween5',
+	new Tween(target5.dataset, group)
+		.to({rotation: '+360', y: '+300'}, 1050)
+		.repeat(Infinity)
+		// .delay(1000) // without delay
+		.yoyo(true)
+		.easing(Easing.Quadratic.InOut)
+		.onUpdate(function (object) {
+			updateBox(target5, object)
+		})
+		.start(),
+)
 
 // TODO perhaps add these methods to Group
 
 const restart = (window.restart = function () {
-	tween1.stop().start()
-	tween2.stop().start()
-	tween3.stop().start()
-	tween4.stop().start()
+	tweenMap.forEach(tween => tween.start())
 })
 
 const stop = (window.stop = function () {
-	tween1.stop()
-	tween2.stop()
-	tween3.stop()
-	tween4.stop()
+	tweenMap.forEach(tween => tween.stop())
 })
 
 const start = (window.start = function () {
-	tween1.start()
-	tween2.start()
-	tween3.start()
-	tween4.start()
+	tweenMap.forEach(tween => tween.start())
 })
 
 const pause = (window.pause = function () {
-	tween1.pause()
-	tween2.pause()
-	tween3.pause()
-	tween4.pause()
+	tweenMap.forEach(tween => tween.pause())
 })
 
 const resume = (window.resume = function () {
-	tween1.resume()
-	tween2.resume()
-	tween3.resume()
-	tween4.resume()
+	tweenMap.forEach(tween => tween.resume())
 })
 
 function animate(time) {

diff --git a/package.json b/package.json
@@ -1,7 +1,7 @@
 {
 	"name": "@tweenjs/tween.js",
 	"description": "Simple and fast tweening engine with optimised Robert Penner's equations.",
-	"version": "25.0.0",
+	"version": "25.0.1",
 	"type": "module",
 	"main": "dist/tween.cjs",
 	"types": "dist/tween.d.ts",

diff --git a/src/Tween.ts b/src/Tween.ts
@@ -473,7 +473,8 @@ export class Tween<T extends UnknownProps = any> {
 			this._onEveryStartCallbackFired = true
 		}
 
-		const elapsedTime = time - this._startTime
+		const elapsedTime = this._yoyo ? Math.min(time - this._startTime, this._duration) : time - this._startTime
+
 		const durationAndDelay = this._duration + (this._repeatDelayTime ?? this._delayTime)
 		const totalTime = this._duration + this._repeat * durationAndDelay
 

diff --git a/src/Version.ts b/src/Version.ts
@@ -1,2 +1,2 @@
-const VERSION = '25.0.0'
+const VERSION = '25.0.1'
 export default VERSION