The Swapper is an efficient way to build many of the shapes. It seems to me it's an underrated building because players already understand how the other buildings work and just use them instead. I'm hoping to provide some familiarity with the swapper to help players make use of it because it's great and fun to use. And, to do so without giving away specific in-game uses which would belong in a spoiler tag.


Also, I have other guides:

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3513035306

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3511915001

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3334747691

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3320548627

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3511195417

• Rotate 90 or CW is for clockwise; it moves the top "to the right"
  
• Rotate -90 or CCW is for counter-clockwise; it moves the top "to the left"
  
• Rotate 180 turns it around the opposite way
  
• halver - what I call the "half-destroyer"
  
• west and east - when the game has the North toward the top (by the compass in bottom left) then the swapper swaps the left sides of the two shapes. Instead of "left", the game calls them "west" because we can spin the screen's view and the swappers will no longer be moving the "left", but it will still move the "west", according to that compass. It is easiest to keep the game facing North, but, not required. Instead, the swapper uses two colors to show which side is which. The west side is blue and and the east side is black.

I'm starting with single swap operations and focusing on the basic rule of the swapper: "Only the West Side Moves"; which is the blue side.


The swapper doesn't change the east side of the shapes at all.

They always pass through and come out the other side the same.

The image to the left shows two shapes. They both only have an east side so nothing happens to them.




When both shapes only have west sides, then they'll both move to the opposite belt. This is a way to swap which belt the shapes are on. This is also possible with whole shapes, tho, that requires a second swap; I'll show it later.





It's possible to use a swapper to combine the two half shapes into a whole shape by making one of them a west side and the other an east side.

We control which side of the swapper the whole shape comes out of by sending the east side shape to the side we want the whole shape on.

The image above shows both versions, sending it left, and sending it right. The side which ends up with nothing shows an X.




Going back to two east side shapes, when I add a west side to one of them it will be swapped to the other shape; as shown in the image to the left.




When I add a different west side to the other shape, the image on the left shows the two west sides swapping.

Above, the "One Swap" work rotated shapes before the swap to control what it does. Now, let's do that twice in a row with a second pair of rotation and swap. With this, we can make often used shapes:

1. 4x diagonal corners
   
2. 3+1 mixed shapes
   
3. 2x diagonal corners

The "Two Whole Shapes" above shows swapping two different whole shapes to have half of each in the output shape.

A second rotate+swap will mix the halves creating quarters of each in opposite corners.



When we only rotate one of the shapes in between, then we can swap in a single piece of a shape into another one so 3 of its corners are one shape and 1 is another. I call it 3+1. At the same time, it'll make the opposite 3+1, too. Sometimes, both are useful.



This one starts with a cutter instead of a swap, so, not technically "two swaps"; but it's two steps with rotation in between.

So, first cut it into halves. Then, we do the same as above in "4x diagonal corners" to turn those halves into opposite corners. The difference is, this one doesn't have half of a second shape, so it only has one pair of diagonal corners.



When deciding which rotators/belts to put in between two swappers, there are a lot of variations to choose from. As shown above, some decide which shape is created. Others simply make a different orientation of one of those shapes. Below is an image showing eight variations of the 3+1 shape. The ones in the bottom row are a repeat of the top row with the lone belts replaced with Rotate 180's. Studying all these variations will show how we control the orientation of the output shapes.

Unlike cutting, stacking, painting, and mixing, swapping can be undone, or, done in the opposite direction; mostly. Separating quarters takes a bit more work than the others.

Below I'll show some images which are setup in loops. They'll do some swap work on the left side with input at the top and output at the bottom. Then, the output will loop around to the right and do the opposite to turn them back into the original input. It repeats infinitely.


To the left is the basic swap of two pure shapes into half-and-half and then back to the pure shapes.


To the left is a two-swap with Rotate 180 in the middle. It uses Rotate 180 to flip the shapes around in between so when they're swapped back into pure shapes they're now on the opposite belts from their original inputs. The loop work on the other side flips them back again.


To the left is the swap corners using the same rotator in between to do the second swap at the alternate orientation to mix all four corners.


To the left is the 3+1 creation using rotation on only one side.


The image above shows creating 2x diagonal corners and then combining them back into a pure shape. The two sides show what happens when flipping the cutter and the reversing the rotators at the same time: it produces the same shapes. If only one had changed then they'd be flipped. Also, one side uses Rotate 90 to output the pure shape on the right, and the other uses Rotate -90 to output it on the left.

Swappers are the same speed as full cutters, bent stackers, and painters: 4 per belt.

They have two side-by-side inputs like mixers, which can be awkward to connect the two different inputs to.

One common method is sending one input from far away via jumps (shape launchers), shown below:


Another common method is sending the inputs on separate levels like the inputs to stackers, with a stepdown or stepup to reach the swapper, shown below with a stepdown:


Below is a variation of the step(up|down) method using less horizontal space:


One quirk of the outputs from swapper groups, which is also true of any output group which has to apply a rotator to half their outputs, is the last output on one side is a belt without a rotator. This allows turning the output upward toward that output and then out the side, as in the below image. It can be useful when trying to fit the group into a tight space. Also, flip things around if the outlet is needed on the other side instead.


There are many other ways depending on what's going on around it.

Also, it's possible to separate shapes into halves with full cutters and combine them with stackers, of course. Below is an image showing the layouts of the two above swapper groups as well as two possible layouts for cutter+stacker groups.



Note, the output belts of both swapper groups can easily output from any point along the belt, or, as mentioned above, from the outer side. While the cutter+stacker groups have limited choices for the output point.

Note, the leftmost group, a cutter+stacker layout, has an interesting quirk: Its output could be reversed and then jump beyond the input belts.

Another thing to note, the larger "stepup" swapper group has a large empty area underneath it. Its overall dimension is 8x5, but, 8x3 of it is on one level.

There are many other layouts possible, especially when the ultimate goals change. More work could be done in the swapper groups before combining into an output belt. Such as more rotations and swaps, as shown in the earlier sections of this guide.

Crystals are only broken by swapping if:

1. two adjacent crystal quarters span west-to-east, because the cut breaks it
   
2. a crystal is touching, either side-by-side or above/below, a crystal broken by the cut

The image above shows the following things, left to right:

1. two east sides don't change, as usual
   
2. two west sides swap places
   
3. one west and one east combine where the east side is
   
4. two whole crystals are broken by the cut
   
5. two half crystals spanning west-to-east are broken by the cut

The image to the left has three half crystals: 1. blue on second layer; 2. white on third layer; and, 3. red on fourth layer. Both the blue and red are sideways and the white is vertical. That makes it seem like they'll break and the white won't, but, there are two problems with that:

First, I've turned the view to face West. Look for the swapper's blue half-circle base showing where "west" is for the swapper. I admit, it can be a little tougher to see in these animations I made, but, it's there.

Second, both the blue and red halves touch the white crystal. That makes all three crystals connected to each other. So, if any of them are broken, they all break. In the image, it cuts across both blue and red, breaking them all.


The image to the left has the same colored half crystals on the same layers as the example above. Except, in this one, they're all sideways and not touching each other. And, with the view facing West the cut is sideways and passes by the crystals without hitting them.

I have more I want to add into the guide but I think it's at a point where I can publish it and then add more later. Please, let me know if I've left something out.


Please, comment if you see any errors, or have a question, or a suggestion to improve the guide.

Please add a thumbs-up if you think the guide is helpful and favorite it to be notified of updates.

Thank you for reading my guide. Have a great day.




+ intro
+ the basic one-swaps
+ the two-swaps
+ the cut+rotate+swap
+ swapper group layouts
+ compare to cutter+stacker layouts
+ show all permutations of 3+1
+ basic crystal swapping

* bugfix. 2x diagonal corners image wasn't showing and wasn't working right.
so, I had to re-upload it with a *different* name to insert it and make it work.

* added link to new Pin Production guide

* added link to new Stacker Specialty guide
* added link to new Paintwise Planning guide

* added link to new Stacker Specialty guide