Raphael: Inherited transformations - raphael

Question

Based on another thread (Raphaeljs transformations with sets)
I have played around with inherited transformations using sets in sets.
I tried to put a set in another set and each set would apply a 45° rotation. I expected, that both rotation would sum up to a 90° rotation. That is working fine.
But both rotations are relative to the centerpoint of each single Object in the Set. How can I achieve, that the rotations are relative to the center point of the Set? Is this possible?
To clarify what I mean. If I have two rectangles in a set and I apply a rotation on the set, I want that the rectangles will stay in the same position and angle relative to them self, because they both rotate around an axis that is between them, in the middle of the set. So they must be translated additionally to the rotation...
how can I achieve this?
jsfiddle:http://jsfiddle.net/bBy9b/
var paper = Raphael(0,0,500,500);
var a = paper.rect(10,10,50,10);
var b = paper.rect(10,30,50,10)
var c = paper.rect(10,50,50,10);
var d = paper.rect(10,70,50,10);
var set = paper.set()
set.push(a);
set.transform("r-45");
var rootSet = paper.set();
rootSet.push(set, b, c);
rootSet.transform("...r-45");
Thx for your help in advance!

Answer 1

The r command takes two additional optional parameters which are the centre point of the rotation. So it looks like you want something like this:
window.onload = function(){
var paper = Raphael(0,0,500,500);
var a = paper.rect(10,10,50,10);
var b = paper.rect(10,30,50,10)
var c = paper.rect(10,50,50,10);
var d = paper.rect(10,70,50,10);
var set = paper.set()
set.push(a);
set.transform("...r-45,40,45");
var rootSet = paper.set();
rootSet.push(set, b, c);
rootSet.transform("...r-45,40,45");
}