/ \
|---------------|------------------------------------|
|-1--1-1--1-1-1-|--------------3--3-3--3-3-3---------|
|-2--2-2--2-2-2-|3--3-3--3-3-3-4--4-4--4-4-4---------|
|-4--4-4--4-4-4-|4--4-4--4-4-4-4--4-4--4-4-4---------|
|-5--5-5--5-5-5-|4--4-4--4-4-4-2--2-2--2-2-2---------|
|---------------|2--2-2--2-2-2-----------------------|
\ repeat x 2 /
|----------------------------------------------------|
|----------------------------------------------------|
|-6--6----6-6-6-6-6-6-6-6-6-6-6----------------------|
|-7--7-7--7-7-7-7-7-7-7-7-7-7-7----------------------|
|-7--7-7--7-7-7-7-7-7-7-7-7-7-7----------------------|
|-5--5-5--5-5-5-5-5-5-5-5-5-5-5----------------------| then back to beginning
