restructure code, internalize devices

src/moto/pack.js

@@ -0,0 +1,64 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+"use strict";
+
+/**
+ * adapted from
+ * http://codeincomplete.com/posts/2011/5/7/bin_packing/
+ */
+
+(function (){
+
+    if (!self.moto) self.moto = {};
+    if (self.moto.Pack) return;
+
+    self.moto.Pack = Packer;
+
+    function Packer (w, h, spacing) {
+        this.root = { x: 0, y: 0, w: w, h: h };
+        this.max = { w: 0, h: 0 };
+        this.packed = false;
+        this.spacing = typeof(spacing) === 'number' ? spacing : 1;
+        this.pad = this.spacing / 2;
+    }
+
+    Packer.prototype = {
+
+        fit: function (blocks) {
+            let n = 0, node, block, w, h;
+            while (n < blocks.length) {
+                block = blocks[n++];
+                w = block.w + this.spacing;
+                h = block.h + this.spacing;
+                if (node = this.findNode(this.root, w, h)) {
+                    block.fit = this.splitNode(node, w, h);
+                } else {
+                    return this;
+                }
+            }
+            this.packed = true;
+            return this;
+        },
+
+        findNode: function (root, w, h) {
+            if (root.used) {
+                return this.findNode(root.right, w, h) || this.findNode(root.down, w, h);
+            } else if (w <= root.w && h <= root.h) {
+                return root;
+            } else {
+                return null;
+            }
+        },
+
+        splitNode: function (node, w, h) {
+            node.used = true;
+            node.down = { x: node.x, y: node.y + h, w: node.w, h: node.h - h };
+            node.right = { x: node.x + w, y: node.y, w: node.w - w, h: h };
+            this.max.w = Math.max(this.max.w, node.x + w);
+            this.max.h = Math.max(this.max.h, node.y + h);
+            return node;
+        }
+
+    };
+
+})();