new flickering light script

examples/acScripts/flickeringLight.js

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+//
+//  flickeringLight.js
+//  examples
+//
+//  Created by Brad Hefta-Gaub on 2015/09/29.
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Creates an ephemeral flickering light that will randomly flicker as long as the script is running.
+//  After the script stops running, the light will eventually disappear (~10 seconds later). This script
+//  can run in the interface or in an assignment client and it will work equally well.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+
+function randFloat(low, high) {
+    return low + Math.random() * (high - low);
+}
+
+var LIGHT_NAME = "flickering fire";
+
+var LIGHT_POSITION = {
+    x: 551.13,
+    y: 494.77,
+    z: 502.26
+};
+
+var LIGHT_COLOR = {
+    red: 255,
+    green: 100,
+    blue: 28
+};
+
+var ZERO_VEC = {
+    x: 0,
+    y: 0,
+    z: 0
+};
+
+var totalTime = 0;
+
+var MINIMUM_LIGHT_INTENSITY = 0.75;
+var MAXIMUM_LIGHT_INTENSITY = 2.75;
+var LIGHT_INTENSITY_RANDOMNESS = 0.3;
+var EPHEMERAL_LIFETIME = 10; // ephemeral entities will live for 10 seconds after script stops running
+
+var LightMaker = {
+    light: null,
+    spawnLight: function() {
+        print('CREATING LIGHT')
+        var _this = this;
+        _this.light = Entities.addEntity({
+            type: "Light",
+            name: LIGHT_NAME,
+            position: LIGHT_POSITION,
+            lifetime: EPHEMERAL_LIFETIME,
+            color: LIGHT_COLOR,
+            dimensions: { x: 10, y: 10, z: 10 }
+        });
+    }
+}
+
+var hasSpawned = false;
+
+function update(deltaTime) {
+
+    if (!Entities.serversExist() || !Entities.canRez()) {
+        return;
+    }
+
+    if (hasSpawned === false) {
+        hasSpawned = true;
+        LightMaker.spawnLight();
+    } else {
+        totalTime += deltaTime;
+        var intensity = (MINIMUM_LIGHT_INTENSITY + (MAXIMUM_LIGHT_INTENSITY + (Math.sin(totalTime) * MAXIMUM_LIGHT_INTENSITY)));
+        intensity += randFloat(-LIGHT_INTENSITY_RANDOMNESS, LIGHT_INTENSITY_RANDOMNESS);
+        var properties = Entities.getEntityProperties(LightMaker.light, "age");
+        Entities.editEntity(LightMaker.light, { intensity: intensity, lifetime: properties.age + EPHEMERAL_LIFETIME });
+    }
+}
+
+Script.update.connect(update);