add poly-decamp require shim

Gulpfile.js

@@ -105,7 +105,8 @@ gulp.task('watch', function() {
     var b = browserify({
         entries: ['src/module/main.js'],
         standalone: 'Matter',
-        plugin: [watchify]
+        plugin: [watchify],
+        transform: ['browserify-shim']
     });
 
     var bundle = function() {
@@ -249,7 +250,7 @@ var build = function(options) {
 
     var compiled = gulp.src(['src/module/main.js'])
         .pipe(through2.obj(function(file, enc, next){
-            browserify(file.path, { standalone: 'Matter' })
+            browserify(file.path, { standalone: 'Matter', transform: ['browserify-shim'] })
                 .bundle(function(err, res){
                     file.contents = res;
                     next(null, file);

package.json

@@ -21,6 +21,7 @@
   ],
   "devDependencies": {
     "browserify": "^12.0.1",
+    "browserify-shim": "^3.8.12",
     "cheerio": "^0.19.0",
     "connect-livereload": "^0.5.4",
     "event-stream": "^3.3.2",
@@ -58,5 +59,8 @@
     "src",
     "build",
     "CHANGELOG.md"
-  ]
+  ],
+  "browserify-shim": {
+    "poly-decomp": "global:decomp"
+  }
 }

src/factory/Bodies.js

@@ -18,6 +18,7 @@ var Common = require('../core/Common');
 var Body = require('../body/Body');
 var Bounds = require('../geometry/Bounds');
 var Vector = require('../geometry/Vector');
+var decomp = require('poly-decomp');
 
 (function() {
 
@@ -213,8 +214,6 @@ var Vector = require('../geometry/Vector');
         removeCollinear = typeof removeCollinear !== 'undefined' ? removeCollinear : 0.01;
         minimumArea = typeof minimumArea !== 'undefined' ? minimumArea : 10;
 
-        var decomp = window.decomp;
-
         if (!decomp) {
             Common.warn('Bodies.fromVertices: poly-decomp.js required. Could not decompose vertices. Fallback to convex hull.');
         }