I've created a GitHub repository with the Slideshow library. The repository has the Slideshow class, an example program, and 5 files that are used by the example program. The repository is here:
https://github.com/mjborgerson/Slideshow
The Slideshow library also requires the latest version of the PXP library, which is here:
https://github.com/mjborgerson/PXP
To run the Slideshow example you will need the following hardware:
* T4.1 or a T4.0 with an attached SD card socket.
* An ILI9341 display compatible with the ILI9341_t3n library.
You will also need the latest version of the SD library from TD 1.54b5.
Procedure:
Download the zip files for the Slideshow and the PXP libraries. Extract these libraries and put them in your sketches/libraries folder in folders named "Slideshow" and "PXP"
In the Slideshow folder, there is an Examples folder. This folder contains a folder named "Slideshow_test" . In that folder you can find the Slideshow_test.ino example program and a folder named "Slideshow files" The slide show files need to be moved from this folder to the root directory of the SD card from the Teensy. When you have copied the files, you can run the Slideshow_test.ino sketch.
The Slideshow test was inspired by the screensaver on my IMac. However, the use of the PXP for scaling and transitioning between images should also be useful in applications like touchscreen GUIs, where you may want to display a splash screen or switch between gui panels in a less jarring manner than a fast switch to a new panel.