added OverlayPreloader and made a bunch of clones

examples/clonedOverlaysExample.js

@@ -11,6 +11,9 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
+const NUM_OF_TREES = 40;
+const NUM_OF_SANTAS = 20;
+
 // Image source: https://openclipart.org/detail/447/christmas-tree-by-theresaknott (heavily edited by Maximillian Merlin)
 const CHRISTMAS_TREE_SPRITES_URL = "http://test.thoys.nl/hifi/images/santa/christmas-tree.svg";
 
@@ -27,13 +30,31 @@ Array.prototype.contains = function(obj) {
     return false;
 };
 
-function getRandomPosAroundMyAvatar(radius) {
+function getRandomPosAroundMyAvatar(radius, height_offset) {
-    return {x: MyAvatar.position.x + Math.floor(Math.random() * radius * 2) - radius, y: MyAvatar.position.y, z: MyAvatar.position.z + Math.floor(Math.random() * radius * 2) - radius};
+    if (height_offset == undefined) {
+        height_offset = 0;
+    }
+    return {x: MyAvatar.position.x + Math.floor(Math.random() * radius * 2) - radius, y: MyAvatar.position.y + height_offset, z: MyAvatar.position.z + Math.floor(Math.random() * radius * 2) - radius};
 }
 
-function SpriteBillboard(sprite_properties) {
+function OverlayPreloader(overlay_type, overlay_properties, loaded_callback) {
     var _this = this;
+    this.loaded_callback = loaded_callback;
+    this.overlay = Overlays.addOverlay(overlay_type, overlay_properties);
+    this.timer = null;
+    this.timer = Script.setInterval(function() { 
+        if (Overlays.isLoaded(_this.overlay)) {
+            Script.clearInterval(_this.timer);
+            _this.loaded_callback();
+        }
+    }, 100);
+}
+
+function SpriteBillboard(sprite_properties, overlay) {
+    var _this = this;
+    
     // set properties
+    this.overlay = overlay;
     this.overlay_properties = {};
     this.sprite_properties = sprite_properties;
     this.edited_overlay_properties = [];
@@ -67,12 +88,6 @@ function SpriteBillboard(sprite_properties) {
         return _this;
     };
 
-    this.setURL = function(url) {
-        this.overlay_properties.url = url;
-        this.editedProperty("url");
-        return _this;
-    }
-
     this.setAlpha = function(alpha) {
         this.overlay_properties.alpha = alpha;
         this.editedProperty("alpha");
@@ -171,7 +186,6 @@ function SpriteBillboard(sprite_properties) {
                 YMoveNext = Math.abs(nextY - _this.sequenceY) == 1;
             }
             canMoveToNext = XMoveNext && YMoveNext;
-		   
         }
         if (canMoveToNext) {
             _this.sequenceIndex = nextIndex;
@@ -223,9 +237,7 @@ function SpriteBillboard(sprite_properties) {
         this.setPosition(this.sprite_properties.position);
     }
 
-    // set the overlay
+    _this.commitChanges();
-    this.overlay = Overlays.addOverlay("billboard", this.overlay_properties);
-    this.new_properties = {};
 
     if (this.sprite_properties.startup_sequence != undefined) {
         this.start(this.sprite_properties.startup_sequence);
@@ -239,20 +251,30 @@ function SpriteBillboard(sprite_properties) {
     });
 }
 
-var chrismastree = new SpriteBillboard({
+var christmastree_loader = null;
-    position: getRandomPosAroundMyAvatar(6),
+christmastree_loader = new OverlayPreloader("billboard", 
-    url: CHRISTMAS_TREE_SPRITES_URL,
+    {url: CHRISTMAS_TREE_SPRITES_URL, alpha: 0}, function() {
+        for (var i = 0; i < NUM_OF_TREES; i++) {
+            var clonedOverlay = Overlays.cloneOverlay(christmastree_loader.overlay);
+            new SpriteBillboard({
+                position: getRandomPosAroundMyAvatar(20),
                 sprite_size: {x: 0, y: 0, width: 250.000, height: 357.626},
                 scale: 6,
                 alpha: 1,
                 sequences: {"idle": [{x: 0, y: 0, step_to_next: true, fps: 3}, {x: 3, step_to_next: false}]},
                 startup_sequence: "idle"
-});
+            }, clonedOverlay);
+        }
+    }
+);
 
-var santa = new SpriteBillboard({
+var santa_loader = null;
-    position: getRandomPosAroundMyAvatar(6),
+santa_loader = new OverlayPreloader("billboard", 
-    url: SANTA_SPRITES_URL,
+    {url: SANTA_SPRITES_URL, alpha: 0}, function() {
-    loop: true,
+        for (var i = 0; i < NUM_OF_SANTAS; i++) {
+            var clonedOverlay = Overlays.cloneOverlay(santa_loader.overlay);
+            new SpriteBillboard({
+                position: getRandomPosAroundMyAvatar(18, -1),
                 sprite_size: {x: 0, y: 0, width: 64, height:  72},
                 scale: 4,
                 alpha: 1,
@@ -260,19 +282,13 @@ var santa = new SpriteBillboard({
                     "walk_left": [{x: 2, y: 0, step_to_next: true, fps: 4}, {x: 10, step_to_next: false}],
                     "walk_right": [{x: 10, y: 1, step_to_next: true, fps: 4}, {x: 2, step_to_next: false}],
                 },
-    startup_sequence: "walk_left"
+                startup_sequence: (i % 2 == 0) ? "walk_left" : "walk_right"
-});
+            }, clonedOverlay);
+        }
+    }
+);
 
-var santa = new SpriteBillboard({
+Script.scriptEnding.connect(function () {
-    position: getRandomPosAroundMyAvatar(6),
+    Overlays.deleteOverlay(christmastree_loader.overlay);
-    url: SANTA_SPRITES_URL,
+    Overlays.deleteOverlay(santa_loader.overlay);
-    loop: true,
-    sprite_size: {x: 0, y: 0, width: 64, height:  72},
-    scale: 4,
-    alpha: 1,
-    sequences: {
-		"walk_left": [{x: 2, y: 0, step_to_next: true, fps: 4}, {x: 10, step_to_next: false}],
-		"walk_right": [{x: 10, y: 1, step_to_next: true, fps: 4}, {x: 2, step_to_next: false}],
-	},
-    startup_sequence: "walk_right"
 });