i didnt think i was the only one that found the rectanglestyle to be a bit confusing, so i ran through many tests to find out what exactly happends.
-first off, it does not need 9 elements, you can get away with just 1.
-how the images will line up all depend on sizes, but all are next to the center frame
Code:
+---+----------+----+
| | | |
+-+-+----------+----+
| | | |
| | | |
| | | |
+-+----------+----+-+
| | | |
+-+----------+ |
+------+
-notice how the the different sizes align with the center frame.
-the corners will always be a 1:1 ratio.
-the sides (n,s,e,w) are a 1:1 ratio from center to edge, but varry from corner to corner (n will be a varied width from nw to ne)
Shrink and Stretch
-these names were the hardest part, because they do no operate as you would image.
shrink=true, stretch=true: image will scale, and will not repeat
shrink=true, stretch=false: image will not scale, repeated image will scale
shrink=false, stretch=true:image will not scale, and will not repeat (default)
shrink=false, stretch=false: image will not scale, repeated image will not scale
shrink true=scale, false=dont scale
stretch true=dont repeat, false=repeat
-as you can see the words do not really match their meanings
-the way i remember is shrink=scale, stretch=opposite of repeat
with clever planning you can setup very useful rectanglestyle's. i decided to post this after working out a background with a large gradient where the bottom faded to black, and thought someone might be able to learn from my headache