updated npm package nexus3d to modern standards

Author: ponchio

nexus3d/package.json

@@ -32,13 +32,16 @@
   "dependencies": {
     "three": "^0.181.0"
   },
-  "files": [
-    "build/nexus3D.min.js",
-    "build/nexus3D.js",
-    "dist/corto.em.js",
-    "LICENSE",
-    "package.json",
-    "README.md",
-    "src"
-  ]
+"files": [
+  "build/nexus3D.js",
+  "build/nexus3D.min.js",
+  "build/corto.worker.js"
+],
+"exports": {
+  ".": {
+    "import": "./build/nexus3D.js",
+    "require": "./build/nexus3D.min.js"
+  },
+  "./worker": "./build/corto.worker.js"
+}
 }

nexus3d/rollup.config.js

@@ -1,32 +1,37 @@
 import { terser } from "rollup-plugin-terser";
 
-function header() {
-	return {
-
-		renderChunk( code ) {
-			return "// vcg.isti.cnr.it/nexus/license\n" + code;
-		}
-	};
-
-}
+// Helper for license header
+const license = "// vcg.isti.cnr.it/nexus/license\n";
 
 export default [
-	{
-		input: './src/Nexus3D.js',
-		output: [{
-			format: 'umd',
-			name: 'Nexus3D',
-			file: 'build/nexus3D.min.js',
-			plugins: [terser()],
-			globals: { three: 'THREE' }
-		},
-		{
-			format: 'umd',
-			name: 'Nexus3D',
-			file: 'build/nexus3D.js',
-			globals: { three: 'THREE' }
-		}],
-		external: [ 'three' ]
-	}
-	
-];
+    // Build the Main Library (Nexus3D)
+    {
+        input: './src/Nexus3D.js',
+        output: [
+            {
+                format: 'es',
+                file: 'build/nexus3D.js',
+            },
+            {
+                format: 'umd',
+                name: 'Nexus3D',
+                file: 'build/nexus3D.min.js',
+                plugins: [terser()],
+                globals: { three: 'THREE' }
+            }
+        ],
+        external: ['three']
+    },
+    // Build the Worker (Corto)
+    {
+        input: './dist/corto.em.js', 
+        output: {
+            format: 'iife', // Classic worker format is safest for wide compatibility
+            file: 'build/corto.worker.js',
+            plugins: [
+                terser(),
+                { renderChunk: (code) => license + code }
+            ]
+        }
+    }
+];

nexus3d/src/Cache.js

@@ -56,7 +56,13 @@ _Cache.prototype = {
     setTargetError:  function(error) { this.targetError = error; },
 
     loadCorto: function() {
-        let corto = new Worker(this.cortopath + '/corto.em.js');
+        let workerPath = this.cortopath + 'corto.worker.js'; 
+        try {
+            workerPath = new URL('./corto.worker.js', import.meta.url).href;
+        } catch (e) {
+            //reverrt to es if import.meta.url is not available
+        }
+        let corto = new Worker(workerPath);
         corto.requests = {};
         corto.count = 0;
         corto.postRequest = function(node) {