Add new rollup config

rollup-examples.config.js

@@ -0,0 +1,69 @@
+const path = require( 'path' );
+const fs = require( 'fs' );
+
+// Creates an rollup config object for the given file to
+// be output to umd format
+function createOutput( file ) {
+
+	const inputPath = path.resolve( file );
+	const outputPath = inputPath.replace( /[\\\/]examples[\\\/]modules[\\\/]/, '/examples/js/' );
+
+	// Every import is marked as external so the output is 1-to-1. We
+	// assume that that global object should be the THREE object so we
+	// replicate the existing behavior.
+	return {
+
+		input: inputPath,
+		treeshake: false,
+		external: p => p !== inputPath,
+
+		output: {
+
+			format: 'umd',
+			name: 'THREE',
+			file: outputPath,
+
+			globals: () => 'THREE',
+			extend: true,
+
+			indent: false,
+			banner:
+				'/**\n' +
+				` * Generated from '${ path.relative( '.', inputPath.replace( /\\/, '/' ) ) }'\n` +
+				' **/\n'
+
+		}
+
+	};
+
+}
+
+// Walk the file structure starting at the given directory and fire
+// the callback for every file.
+function walk( dir, cb ) {
+
+	const files = fs.readdirSync( dir );
+	files.forEach( f => {
+
+		const p = path.join( dir, f );
+		const stats = fs.statSync( p );
+		if ( stats.isDirectory() ) {
+
+			walk( p, cb );
+
+		} else {
+
+			cb( p );
+
+		}
+
+	} );
+
+}
+
+// Gather up all the files
+const files = [];
+walk( 'examples/jsm/', p => files.push( p ) );
+
+// Create a rollup config for each module.js file
+export default files.map( p => createOutput( p ) );