Version: 4.1

## Tiles Teachpack

### 1This teachpack

The tiles teachpack provides a variety of functions for combining and manipulating images. Imagine that each image were on a ceramic tile; you would expect to be able to put two tiles together side by side, or one above another, or rotate a tile, etc. That’s exactly what this teachpack provides.

 (image-above img1 img2 ...) → image? img1 : image? img2 : image?

Combines two or more images into one, putting the first above the second (above the third, ...).

 (image-above-align-right img1 img2 ...) → image? img1 : image? img2 : image?

Just like image-above, but lines up the right-hand edges of all the images.

 (image-above-align-left img1 img2 ...) → image? img1 : image? img2 : image?

Just like image-above, but lines up the left-hand edges of all the images.

 (image-above-align-center img1 img2 ...) → image? img1 : image? img2 : image?

Just like image-above, but lines up the centers of all the images.

 (image-beside img1 img2 ...) → image? img1 : image? img2 : image?

Combines two or more images into one, putting the first to the left of the second (to the left of the third, ...).

 (image-beside-align-top img1 img2 ...) → image? img1 : image? img2 : image?

Just like image-beside, but lines up the top edges of all the images.

 (image-beside-align-bottom img1 img2 ...) → image? img1 : image? img2 : image?

Just like image-beside, but lines up the bottom edges of all the images.

 (image-beside-align-center img1 img2 ...) → image? img1 : image? img2 : image?

Just like image-beside, but lines up the centers of all the images.

 (reflect-vert img) → image? img : image?

Flips an image top-to-botom.

 (reflect-horiz img) → image? img : image?

Flips an image left-to-right.

 (reflect-main-diag img) → image? img : image?

Flips an image from top-right to bottom-left, leaving the top-left and bottom-right unchanged.

 (reflect-other-diag img) → image? img : image?

Flips an image from top-left to bottom-right, leaving the top-right and bottom-left unchanged.

 (rotate-cw img) → image? img : image?

Rotates an image 90 degrees clockwise.

 (rotate-ccw img) → image? img : image?

Rotates an image 90 degrees counterclockwise.

 (rotate-180 img) → image? img : image?

Rotates an image 180 degrees around its center.

 (show-pinhole img) → image? img : image?

Overlays a small black dot at the pinhole of the given image, so you can see where it is. (This function will go away when pinholes go away....)

 (crop-top img pixels) → image? img : image? pixels : natural-number/c

Chops off the specified number of pixels from the top of the image.

 (crop-bottom img pixels) → image? img : image? pixels : natural-number/c

Chops off the specified number of pixels from the bottom of the image.

 (crop-left img pixels) → image? img : image? pixels : natural-number/c

Chops off the specified number of pixels from the left side of the image.

 (crop-right img pixels) → image? img : image? pixels : natural-number/c

Chops off the specified number of pixels from the right side of the image.

### 2Functions from image.ss

Since anybody using these functions will almost certainly also want to use other image-creation and image-manipulation functions, this teachpack includes the standard teachpack image.ss. That is, if you have tiles.ss loaded, you don’t also need image.ss (and you’re better off not loading it).