Fix animator play backwards error and onStateExit not triggered when crossFade finished and actualDeltaTime error

e2e/case/animator-play-backwards.ts

@@ -0,0 +1,38 @@
+/**
+ * @title Animation Play
+ * @category Animation
+ */
+import { Animator, Camera, DirectLight, GLTFResource, Logger, Vector3, WebGLEngine } from "@galacean/engine";
+import { OrbitControl } from "@galacean/engine-toolkit";
+import { initScreenshot, updateForE2E } from "./.mockForE2E";
+
+Logger.enable();
+WebGLEngine.create({ canvas: "canvas" }).then((engine) => {
+  engine.canvas.resizeByClientSize(2);
+  const scene = engine.sceneManager.activeScene;
+  const rootEntity = scene.createRootEntity();
+
+  // camera
+  const cameraEntity = rootEntity.createChild("camera_node");
+  cameraEntity.transform.position = new Vector3(0, 1, 5);
+  const camera = cameraEntity.addComponent(Camera);
+  cameraEntity.addComponent(OrbitControl).target = new Vector3(0, 1, 0);
+
+  const lightNode = rootEntity.createChild("light_node");
+  lightNode.addComponent(DirectLight).intensity = 0.6;
+  lightNode.transform.lookAt(new Vector3(0, 0, 1));
+  lightNode.transform.rotate(new Vector3(0, 90, 0));
+
+  engine.resourceManager
+    .load<GLTFResource>("https://gw.alipayobjects.com/os/bmw-prod/5e3c1e4e-496e-45f8-8e05-f89f2bd5e4a4.glb")
+    .then((gltfResource) => {
+      const { defaultSceneRoot } = gltfResource;
+      rootEntity.addChild(defaultSceneRoot);
+      const animator = defaultSceneRoot.getComponent(Animator);
+      animator.findAnimatorState("walk").speed = -1;
+      animator.play("walk");
+      updateForE2E(engine);
+
+      initScreenshot(engine, camera);
+    });
+});

e2e/config.ts

@@ -45,6 +45,11 @@ export const E2E_CONFIG = {
       caseFileName: "animator-play",
       threshold: 0.1
     },
+    playBackWards: {
+      category: "Animator",
+      caseFileName: "animator-play-backwards",
+      threshold: 0.1
+    },
     playBeforeActive: {
       category: "Animator",
       caseFileName: "animator-play-beforeActive",

packages/core/src/animation/Animator.ts

@@ -548,27 +548,25 @@ export class Animator extends Component {
     srcPlayData.update(playDeltaTime);
 
     const { clipTime, isForwards } = srcPlayData;
+    const { transitions } = state;
+    const { anyStateTransitions } = layer.stateMachine;
+
     const transition =
-      this._applyTransitionsByCondition(
-        layerIndex,
-        layerData,
-        layer,
-        state,
-        layer.stateMachine.anyStateTransitions,
-        aniUpdate
-      ) ||
-      this._applyStateTransitions(
-        layerIndex,
-        layerData,
-        layer,
-        isForwards,
-        srcPlayData,
-        state.transitions,
-        lastClipTime,
-        clipTime,
-        playDeltaTime,
-        aniUpdate
-      );
+      (anyStateTransitions.length &&
+        this._applyTransitionsByCondition(layerIndex, layerData, layer, state, anyStateTransitions, aniUpdate)) ||
+      (transitions.length &&
+        this._applyStateTransitions(
+          layerIndex,
+          layerData,
+          layer,
+          isForwards,
+          srcPlayData,
+          transitions,
+          lastClipTime,
+          clipTime,
+          playDeltaTime,
+          aniUpdate
+        ));
 
     let playCostTime: number;
     if (transition) {
@@ -899,28 +897,25 @@ export class Animator extends Component {
     playData.updateOrientation(actualDeltaTime);
 
     const { clipTime, isForwards } = playData;
+    const { transitions } = state;
+    const { anyStateTransitions } = layer.stateMachine;
 
     const transition =
-      this._applyTransitionsByCondition(
-        layerIndex,
-        layerData,
-        layer,
-        state,
-        stateMachine.anyStateTransitions,
-        aniUpdate
-      ) ||
-      this._applyStateTransitions(
-        layerIndex,
-        layerData,
-        layer,
-        isForwards,
-        playData,
-        state.transitions,
-        clipTime,
-        clipTime,
-        actualDeltaTime,
-        aniUpdate
-      );
+      (anyStateTransitions.length &&
+        this._applyTransitionsByCondition(layerIndex, layerData, layer, state, anyStateTransitions, aniUpdate)) ||
+      (transitions.length &&
+        this._applyStateTransitions(
+          layerIndex,
+          layerData,
+          layer,
+          isForwards,
+          playData,
+          transitions,
+          clipTime,
+          clipTime,
+          actualDeltaTime,
+          aniUpdate
+        ));
 
     if (transition) {
       this._updateState(layerIndex, layerData, layer, deltaTime, aniUpdate);