In attempting not to reinvent the wheel, are there any lightweight tools that take a single BED12 element and quickly render its intron/UTR/CDS structure and directionality? 

I'm not looking for a heavyweight toolkit or framework that renders a static genome browser shot of multiple BED12 elements, but something that takes in an element and simply shows a rough sketch of its structure. Thanks for any tips!
a very basic html form  converting a bed12 entry to SVG : 

https://gist.github.com/lindenb/3dd99f6429b7dc2092e0d1c94d74ed65