Textural triangle plot in R

Hi,
these days I'm working with soil textural data and one of the key point of these data is the presentation of the results.
The best way is a old-school texture triangle!!!

Because I like to do all my stuff in R, instead of opening draw software such as corel draw or adobe illustrator, I started looking at packages for this kind of plot.

I think the best one is plotrix, because it let's you plot the USDA or UK textura triangle, so in the end the image is ready for publication.

I prepared a little script to show how to create a simple plot, adding the legend and save it as image file.
The script is downloadable from this link:
R script

I'm also preparing a little video for showing how to use the script but if you are familiar with R, you don't need it.