From 18dd5eb75c5292652c61d3110437cf7404b5812d Mon Sep 17 00:00:00 2001
From: cha0s <git@cha0s.io>
Date: Mon, 9 May 2022 11:01:16 -0500
Subject: [PATCH] opt: pool

---
 packages/entity/src/resources/entity.js | 14 +++++++++++++
 packages/physics/src/traits/emitter.js  | 27 +++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/packages/entity/src/resources/entity.js b/packages/entity/src/resources/entity.js
index 53c42ed..cd3b699 100644
--- a/packages/entity/src/resources/entity.js
+++ b/packages/entity/src/resources/entity.js
@@ -199,6 +199,20 @@ export default (flecks) => {
       });
     }
 
+    static dependencyTree(types) {
+      const Traits = flecks.get('$avocado/traits.traits');
+      const tree = new Set(types);
+      const checking = types;
+      while (checking.length > 0) {
+        const Trait = Traits[checking.pop()];
+        if (Trait) {
+          checking.push(...Trait.dependencies());
+          tree.add(Trait.type);
+        }
+      }
+      return tree;
+    }
+
     async destroy() {
       if (this.$$isDestroying) {
         return;
diff --git a/packages/physics/src/traits/emitter.js b/packages/physics/src/traits/emitter.js
index 454b079..0f004db 100644
--- a/packages/physics/src/traits/emitter.js
+++ b/packages/physics/src/traits/emitter.js
@@ -24,6 +24,8 @@ export default (flecks) => class Emitter extends decorate(Trait) {
 
   $$particles = {};
 
+  $$pool = [];
+
   $$proton = new Proton();
 
   $$streams = [];
@@ -59,7 +61,25 @@ export default (flecks) => class Emitter extends decorate(Trait) {
 
   async emitParticleJson(json) {
     const {Entity} = flecks.get('$avocado/resource.resources');
-    return this.entity.emitParticleEntity(await Entity.load(json));
+    let entity;
+    if (this.$$pool.length > 0) {
+      entity = this.$$pool.pop();
+      const entityTypes = entity.traitTypes();
+      const jsonTypes = Entity.dependencyTree(Object.keys(json?.traits || {}));
+      const promises = [];
+      for (let i = 0; i < entityTypes.length; ++i) {
+        const entityType = entityTypes[i];
+        if (!jsonTypes.has(entityType)) {
+          promises.push(entity.removeTrait(entityType));
+        }
+      }
+      await Promise.all(promises);
+      await entity.load(json);
+    }
+    else {
+      entity = await Entity.load(json);
+    }
+    return this.entity.emitParticleEntity(entity);
   }
 
   gatherParticles() {
@@ -226,7 +246,10 @@ export default (flecks) => class Emitter extends decorate(Trait) {
   onParticleDead(particle) {
     particle.body.emit('particleDied');
     if (particle.body.isTransientParticle) {
-      particle.body.destroy();
+      if (particle.body.list) {
+        particle.body.list.removeEntity(particle.body);
+      }
+      this.$$pool.push(particle.body);
     }
   }