Merge pull request #6290 from zzmp/examples/growth

Add growth script to examples

examples/growth.js

@@ -0,0 +1,122 @@
+//
+//  growth.js
+//
+//  Created by Zachary Pomerantz 11/2/2015.
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+var RADIUS = 5;
+var LIFETIME = 60; // only keep these entities around for a minute
+
+var SIZE = 1; // starting size
+var SIZE_MAX = 3;
+var SIZE_MIN = 0.5;
+
+var center = MyAvatar.position;
+var positions = [
+    Vec3.sum(center, Vec3.multiply(RADIUS, Vec3.FRONT)),
+    Vec3.sum(center, Vec3.multiply(-RADIUS, Vec3.FRONT)),
+    Vec3.sum(center, Vec3.multiply(RADIUS, Vec3.RIGHT)),
+    Vec3.sum(center, Vec3.multiply(-RADIUS, Vec3.RIGHT)),
+];
+
+// Create spheres around the avatar
+var spheres = map(positions, getSphere);
+
+// Toggle sphere growth
+each(spheres, function(sphere) {
+    var state = {
+        size: SIZE,
+        grow: true, // grow/shrink
+        state: false, // mutate/pause
+    };
+
+    // Grow or shrink on click
+    Script.addEventHandler(sphere, 'clickReleaseOnEntity', toggleGrowth);
+    // TODO: Toggle on collisions as well
+
+    function toggleGrowth() {
+        if (state.state) {
+            stop();
+        } else {
+            start();
+        }
+    }
+
+    function start() {
+        var verb = state.grow ? 'grow' : 'shrink';
+        print('starting to '+verb+' '+sphere);
+
+        Script.update.connect(grow);
+        state.state = true;
+    }
+
+    function stop() {
+        print('stopping '+sphere);
+
+        Script.update.disconnect(grow);
+        state.state = false;
+        state.grow = !state.grow;
+    }
+
+    function grow(delta) {
+        if ((state.grow && state.size > SIZE_MAX) || // cannot grow more
+            (!state.grow && state.size < SIZE_MIN)) { // cannot shrink more
+            stop();
+            return;
+        }
+
+        state.size += (state.grow ? 1 : -1) * delta; // grow/shrink
+        Entities.editEntity(sphere, { dimensions: getDimensions(state.size) });
+    }
+});
+
+Script.scriptEnding.connect(function() { // cleanup
+    each(spheres, function(sphere) {
+        Entities.deleteEntity(sphere);
+    });
+});
+
+// NOTE: Everything below this line is a helper.
+//       The basic logic of this example is entirely above this note.
+
+// Entity helpers
+
+function getSphere(position) {
+    return Entities.addEntity({
+        type: 'Sphere',
+        position: position,
+        dimensions: getDimensions(SIZE),
+        color: getColor(),
+        gravity: Vec3.ZERO,
+        lifetime: LIFETIME,
+        ignoreCollisions: true,
+    });
+}
+
+function getDimensions(size) {
+    return { x: size, y: size, z: size };
+}
+
+function getColor() {
+    return { red: getValue(), green: getValue(), blue: getValue() };
+    function getValue() { return Math.floor(Math.random() * 255); }
+}
+
+// Functional helpers
+
+function map(list, iterator) {
+    var result = [];
+    for (var i = 0; i < list.length; i++) {
+        result.push(iterator(list[i], i, list));
+    }
+    return result;
+}
+
+function each(list, iterator) {
+    for (var i = 0; i < list.length; i++) {
+        iterator(list[i], i, list);
+    }
+}