From f9a7db6f957a5ddcc0718836c75a925eb7f1da1f Mon Sep 17 00:00:00 2001
From: cha0s <git@cha0s.io>
Date: Sun, 21 Apr 2019 21:54:41 -0500
Subject: [PATCH] feat: animation jitter

---
 packages/timing/traits/animated.trait.js | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/packages/timing/traits/animated.trait.js b/packages/timing/traits/animated.trait.js
index 95bc9a9..e9d2bbd 100644
--- a/packages/timing/traits/animated.trait.js
+++ b/packages/timing/traits/animated.trait.js
@@ -61,6 +61,13 @@ class AnimatedBase extends Trait {
     this.entity.container.removeChild(animationView);
   }
 
+  jitterFor(key) {
+    if (!this._animations[key] || !this._animations[key].jitter) {
+      return 0;
+    }
+    return this._animations[key].jitter;
+  }
+
   loadAnimations() {
     if (this.animationsPromise) {
       return;
@@ -224,11 +231,14 @@ class AnimatedBase extends Trait {
       return;
     }
     // Only tick current animation.
-    const animation = this.animations[this.entity.currentAnimation];
+    const currentAnimation = this.entity.currentAnimation;
+    const animation = this.animations[currentAnimation];
     if (!animation) {
       return;
     }
-    animation.tick(elapsed);
+    const jitter = Math.random() * this.jitterFor(currentAnimation);
+    const halfJitter = jitter / 2;
+    animation.tick(elapsed + (jitter - halfJitter));
   }
 
 }