feat(model): use track types to determine interpolation mode

src/lib/model/ModelAnimator.ts

@@ -3,6 +3,7 @@ import { M2Track } from '@wowserhq/format';
 import { BoneSpec, SequenceSpec } from './loader/types.js';
 import ModelAnimation from './ModelAnimation.js';
 import Model from './Model.js';
+import { getTrackInterpolation } from './util.js';
 
 interface Constructor<T> {
   new (...args: any[]): T;
@@ -152,7 +153,7 @@ class ModelAnimator {
         continue;
       }
 
-      clip.tracks.push(new TrackType(name, times, values));
+      clip.tracks.push(new TrackType(name, times, values, getTrackInterpolation(track.trackType)));
     }
   }
 
@@ -176,7 +177,7 @@ class ModelAnimator {
         continue;
       }
 
-      clip.tracks.push(new TrackType(name, times, values));
+      clip.tracks.push(new TrackType(name, times, values, getTrackInterpolation(track.trackType)));
     }
   }
 

src/lib/model/util.ts

@@ -0,0 +1,18 @@
+import * as THREE from 'three';
+
+const getTrackInterpolation = (trackType: number): THREE.InterpolationModes => {
+  switch (trackType) {
+    case 0:
+      return THREE.InterpolateDiscrete;
+    case 1:
+      return THREE.InterpolateLinear;
+    case 2:
+    case 3:
+      // TODO 2 - cubic bezier, 3 - cubic hermite
+      return THREE.InterpolateSmooth;
+    default:
+      return THREE.InterpolateLinear;
+  }
+};
+
+export { getTrackInterpolation };