From 13508b7fd90a2f253cea4729736b8125ed7433a3 Mon Sep 17 00:00:00 2001
From: Nathan Kunicki <me@nathankunicki.com>
Date: Sun, 14 Feb 2016 01:16:11 +0000
Subject: [PATCH] Particle system appears to be working

---
 examples/particles/particles.js | 41 +++++++++++++++++++++++++++------
 src/classes/emitter.js          | 20 +++++++---------
 2 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/examples/particles/particles.js b/examples/particles/particles.js
index 385e1da..3266e10 100644
--- a/examples/particles/particles.js
+++ b/examples/particles/particles.js
@@ -2,13 +2,18 @@
 
 import MomentumEngine from "../../src/es6";
 
-let white = new MomentumEngine.Classes.Color(255, 255, 255);
+let KeyConsts = MomentumEngine.Consts.Input.Keys;
 
 
 class BlueParticle extends MomentumEngine.Classes.Rect {
 
     constructor (x, y) {
-        super(x, y, 1, 1, white);
+        super(x, y, 1, 1, new MomentumEngine.Classes.Color(255, 255, 255, 0));
+        this.timeToLive = 5000;
+    }
+
+    update (delta) {
+        this.color.a = this.color.a - (delta * 0.00025);
     }
 
 }
@@ -25,7 +30,10 @@ window.onload = function () {
         width: width,
         height: height,
         fixRatio: true,
-        desiredFps: 60
+        desiredFps: 60,
+        inputs: {
+            keyboard: true
+        }
     });
 
     let black = new MomentumEngine.Classes.Color(0, 0, 0),
@@ -34,14 +42,33 @@ window.onload = function () {
     let mainScene = new MomentumEngine.Classes.Rect(0, 0, width, height, black);
     particles.addChildEntity(mainScene);
 
-    let rect = new MomentumEngine.Classes.Rect(width / 10 - baseSize, height - (baseSize * 10), baseSize * 2, baseSize * 2, red),
-        emitter = new MomentumEngine.Classes.Emitter(baseSize, baseSize, 2, new MomentumEngine.Classes.Vector2D(1, 1), BlueParticle);
+    let rect = new MomentumEngine.Classes.Rect(width / 2 - baseSize, height / 2 - baseSize, baseSize * 2, baseSize * 2, red),
+        emitter = new MomentumEngine.Classes.Emitter(baseSize, baseSize, 4, new MomentumEngine.Classes.Vector2D(0, 1), BlueParticle);
 
     mainScene.addChildEntity(rect);
     rect.addChildEntity(emitter);
-    rect.setVelocity(0.01, 0);
-    rect.setAcceleration(0.01, 0);
 
+    rect.update = function (delta) {
+
+        if (particles.inputs.keyboard.isPressed(KeyConsts.UP)) {
+            rect.pos.y -= (0.2 * delta);
+        }
+
+        if (particles.inputs.keyboard.isPressed(KeyConsts.DOWN)) {
+            rect.pos.y += (0.2 * delta);
+        }
+
+        if (particles.inputs.keyboard.isPressed(KeyConsts.LEFT)) {
+            rect.pos.x -= (0.2 * delta);
+        }
+
+        if (particles.inputs.keyboard.isPressed(KeyConsts.RIGHT)) {
+            rect.pos.x += (0.2 * delta);
+        }
+
+    };
+
+    //emitter.spread = Math.PI / 32;
     emitter.setParticleParent(mainScene);
     emitter.emitting = true;
 
diff --git a/src/classes/emitter.js b/src/classes/emitter.js
index e1c6ad3..a46f9b9 100644
--- a/src/classes/emitter.js
+++ b/src/classes/emitter.js
@@ -14,16 +14,13 @@ class Emitter extends Entity {
         this.particleVelocity = velocity;
         this.particleClass = particle;
 
-        this.emitRate = rate;
+        this.rate = rate;
         this.emitting = false;
+        this.spread = Math.PI;
         this._lastEmitTime = this._creationTime;
         this._wasEmitting = false;
 
-        this.particles = [];
-
-        this.spread = function () {
-            return Math.PI / 1;
-        }
+        this._particles = [];
 
     }
 
@@ -38,14 +35,14 @@ class Emitter extends Entity {
         let ParticleClass = this.particleClass,
             parent = this._particleParent || this._parent;
 
-        let angle = this.particleVelocity.angle() + this.spread() - (Math.random() * this.spread() * 2),
+        let angle = this.particleVelocity.angle() + this.spread - (Math.random() * this.spread * 2),
             magnitude = this.particleVelocity.length(),
             velocity = Vector2D.fromAngle(angle, magnitude);
 
         let particle = new ParticleClass(this._calculatedPos.x, this._calculatedPos.y);
         particle.velocity = velocity;
 
-        this.particles.push(particle);
+        //this._particles.push(particle);
         parent.addChildEntity(particle);
 
     }
@@ -66,13 +63,12 @@ class Emitter extends Entity {
                 this._lastEmitTime = currentTime;
             }
 
-            // In honour the code of Alex Evans
             let emitDelta = currentTime - this._lastEmitTime;
-            if (emitDelta > this.emitRate) {
+            if (emitDelta > this.rate) {
 
-                let emissions = ~~(emitDelta / this.emitRate);
+                let emissions = ~~(emitDelta / this.rate);
 
-                this._lastEmitTime = currentTime + (emitDelta - (this.emitRate * emissions));
+                this._lastEmitTime = currentTime + (emitDelta - (this.rate * emissions));
 
                 for (let i = 0; i < emissions; i++) {
                     this._emit();