Bug fix: animation in normal wrap mode won't stop their blend state writers

cocos/core/animation/animation-state.ts

@@ -680,6 +680,9 @@ export class AnimationState extends Playable {
         if (!this.isPaused) {
             this._onPauseOrStop();
         }
+        for (let iBlendStateWriter = 0; iBlendStateWriter < this._blendStateWriters.length; ++iBlendStateWriter) {
+            this._blendStateWriters[iBlendStateWriter].enable(false);
+        }
         this.emit(EventType.STOP, this);
     }
 
@@ -867,6 +870,9 @@ export class AnimationState extends Playable {
             }
             this._isBlendStateWriterInitialized = true;
         }
+        for (let iBlendStateWriter = 0; iBlendStateWriter < this._blendStateWriters.length; ++iBlendStateWriter) {
+            this._blendStateWriters[iBlendStateWriter].enable(true);
+        }
         cc.director.getAnimationManager().addAnimation(this);
     }
 

cocos/core/animation/skeletal-animation-blending.ts

@@ -78,6 +78,7 @@ export class BlendStateBuffer {
 export type IBlendStateWriter = IValueProxyFactory & {
     initialize: () => void;
     destroy: () => void;
+    enable: (enabled: boolean) => void;
 };
 
 export function createBlendStateWriter<P extends BlendingProperty> (
@@ -97,6 +98,7 @@ export function createBlendStateWriter<P extends BlendingProperty> (
     let propertyBlendState: PropertyBlendState<BlendingPropertyValue<P>> | null = null;
     let isConstCacheValid = false;
     let lastWeight = -1;
+    let isEnabled = true;
     return {
         initialize () {
             if (!propertyBlendState) {
@@ -109,9 +111,15 @@ export function createBlendStateWriter<P extends BlendingProperty> (
                 propertyBlendState = null;
             }
         },
+        enable (enabled: boolean) {
+            isEnabled = enabled;
+        },
         forTarget: () => {
             return {
                 set: (value: BlendingPropertyValue<P>) => {
+                    if (!isEnabled) {
+                        return;
+                    }
                     if (!propertyBlendState) {
                         return;
                     }

tests/animation/animation-clip.test.ts

@@ -1,4 +1,4 @@
-import { AnimationClip, js, AnimationState, Node, Component, Vec3 } from '../../cocos/core';
+import { AnimationClip, js, AnimationState, Node, Component, Vec3, AnimationManager } from '../../cocos/core';
 import { ComponentPath } from '../../cocos/core/animation/animation';
 import { ccclass } from '../../cocos/core/data/class-decorator';
 
@@ -65,3 +65,50 @@ test('Common target', () => {
         expect(testComponent.c).toEqual(c);
     }
 });
+
+test('animation state', () => {
+    const animationManager = new AnimationManager();
+    const mockInstance = jest.spyOn((global as any).cc.director, 'getAnimationManager').mockImplementation(() => {
+        return animationManager;
+    });
+
+    const clip = new AnimationClip('default');
+    clip.duration = 2.0;
+    const keys = [
+        0,
+        0.1,
+        0.2,
+    ];
+    const values = [
+        new Vec3(),
+        new Vec3(1),
+        new Vec3(2),
+    ];
+    clip.keys = [keys];
+    clip.curves = [{
+        modifiers: [
+            'position',
+        ],
+        data: {
+            keys: 0,
+            values,
+        },
+    }];
+
+    const state = new AnimationState(clip, clip.name);
+    state.weight = 1.0;
+
+    const node = new Node();
+    state.initialize(node);
+
+    animationManager.update(0);
+    state.play();
+    state.pause();
+
+    state.setTime(keys[1]);
+    state.update(0);
+    animationManager.update(0);
+    expect(node.getPosition()).toEqual(values[1]);
+
+    mockInstance.mockRestore();
+});

tests/animation/animation-events.test.ts

@@ -1,7 +1,7 @@
 import { Node, AnimationComponent, director, AnimationClip, math, AnimationState } from '../../cocos/core';
 
 test('Animation events(general)', () => {
-    jest.spyOn((global as any).cc.director, 'getAnimationManager').mockImplementation(() => {
+    const mockInstance = jest.spyOn((global as any).cc.director, 'getAnimationManager').mockImplementation(() => {
         return {
             addAnimation: () => { },
             removeAnimation: () => { },
@@ -100,6 +100,8 @@ test('Animation events(general)', () => {
     testMagic.clear();
     state.update(clip.duration / 2 + clip.duration / 4);
     testMagic.expectAndClear(AnimationComponent.EventType.LASTFRAME);
+
+    mockInstance.mockRestore();
 });
 
 test('Animation event(last-frame event optimization)', () => {