Proper setup of .htaccess for UFront with PHP

Question

I have a problem with UFront for Haxe: when I run a test PHP server using 'php -S localhost:2397' and visit http://localhost:2397/portfolio/12, UFront handles the route just fine. I'm having trouble doing the same with MAMP.

How can I set up my .htaccess file so I can use MAMP and have it pass the path to UFront properly? This is what I currently have:

RewriteEngine On
RewriteBase /

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1