[Qgis-user] Create polygons from coordinates in graphical modeller

[Grant Boxer]

I am sure there is a simple way to do this, but I am trying to write a 
simple graphical modeller model that will allow me to add four 
coordinate points to create a rectangle/polygon. What algorithm do I use 
to go from four x y coordinate points entered as x1, y1, x2, y2 etc to 
create points in a new layer?

Thanks Grant