refactor: state diffs

packages/entity/trait/index.js

@@ -28,21 +28,15 @@ export class Trait extends decorate(class {}) {
   }
 
   cleanPackets() {
+    for (const key in this.state) {
+      this.previousState[key] = this.state[key];
+    }
   }
 
   static contextType() {
     return {};
   }
 
-  createTraitPacketUpdates(Packet) {
-    const packets = [];
-    if (this.isDirty) {
-      packets.push(new Packet(this.state, this.entity));
-      this.makeClean();
-    }
-    return packets;
-  }
-
   static defaultJSON() {
     return {
       params: this.defaultParams(),
@@ -89,12 +83,6 @@ export class Trait extends decorate(class {}) {
     return {};
   }
 
-  makeClean() {
-    for (const key in this.state) {
-      this.previousState[key] = this.state[key];
-    }
-  }
-
   memoizedListeners() {
     if (!this._memoizedListeners) {
       this._memoizedListeners = this.listeners();
@@ -115,6 +103,19 @@ export class Trait extends decorate(class {}) {
     return false;
   }
 
+  stateDifferences() {
+    const differences = {};
+    for (const key in this.state) {
+      if (this.state[key] !== this.previousState[key]) {
+        differences[key] = {
+          old: this.previousState[key],
+          value: this.state[key],
+        };
+      }
+    }
+    return differences;
+  }
+
   toJSON() {
     return {
       params: this.params,

packages/entity/traits/directional.trait.js

@@ -33,7 +33,6 @@ export class Directional extends decorate(Trait) {
 
   constructor(entity, params, state) {
     super(entity, params, state);
-    this._directionChanged = false;
     this.directionCount = this.params.directionCount;
   }
 
@@ -43,13 +42,10 @@ export class Directional extends decorate(Trait) {
     }
   }
 
-  cleanPackets() {
-    this._directionChanged = false;
-  }
-
   packets(informed) {
-    if (this._directionChanged) {
+    const {direction} = this.stateDifferences();
-      return new TraitUpdateDirectionalDirectionPacket(this.entity.direction);
+    if (direction) {
+      return new TraitUpdateDirectionalDirectionPacket(direction.value);
     }
   }
 

packages/entity/traits/positioned.trait.js

@@ -34,7 +34,6 @@ export class Positioned extends decorate(Trait) {
     const x = this.state.x;
     const y = this.state.y;
     this._position = [x, y];
-    this._positionChanged = false;
     this.entity.position[0] = x;
     this.entity.position[1] = y;
     if (AVOCADO_CLIENT) {
@@ -45,10 +44,6 @@ export class Positioned extends decorate(Trait) {
     }
   }
 
-  cleanPackets() {
-    this._positionChanged = false;
-  }
-
   destroy() {
     this.off('_positionChanged', this.on_positionChanged);
     if (AVOCADO_CLIENT) {
@@ -68,7 +63,6 @@ export class Positioned extends decorate(Trait) {
     if (AVOCADO_SERVER) {
       this.state.x = newPosition[0];
       this.state.y = newPosition[1];
-      this._positionChanged = true;
     }
     this.entity.emit('positionChanged', oldPosition, newPosition);
   }
@@ -78,7 +72,8 @@ export class Positioned extends decorate(Trait) {
   }
 
   packets(informed) {
-    if (this._positionChanged) {
+    const {x, y} = this.stateDifferences();
+    if (x || y) {
       // Physics slop can end us up with negatives. Don't allow them in the
       // packed representation, even though it means a slight loss in accuracy.
       // The world bounds will (should!) keep things *eventually* correct.