vennpieR: combination of venn diagram and pie chart in R

I was wondering how to draw a venn diagram like pie chart in R, to show the distribution of my RNA-seq reads mapped onto different annotation regions (e.g. intergenic, intron, exons etc.). A google search returns several options, including the nice one from Xiaopeng's bam2x (see below). However, he told me it's not released yet. And it's javascript based.

Why not I just make one in R? 

Here is the design scratch:

And here is example code:

Here is output:

You can also use par(mfrow=c(n,m)) to put multiple venn pieagram in one figure.