This is a silent tutorial video; skip to 2:10 for the juicy bit:

This is an animated wallpaper that shows your custom PNG files -- just place them in a particular folder! It also works as a screensaver. It's cpu-friendly, only drawing during transitions.

Installing

• load #photo_carousel
• mkdir /appdata/system/wallpapers
• save /appdata/system/wallpapers/photo_carousel.p64
• run the cart once, to generate the appdata folder
• cd /appdata/photo_carousel
• folder
• using your host OS, copy any PNG files into this folder (don't put them in subfolders)
• set your wallpaper to photo_carousel in System Settings

Settings

Run podtree /appdata/photo_carousel/settings.pod to edit the settings. Be sure to not press enter while editing (this crashes Picotron 0.1.0e) and you must save with the mouse, not ctrl-s (another Picotron bug(?) -- ctrl-s saves the current cart, instead of the settings file)

Set the transition time to 0 to disable transitions

Details

Converting PNGs

This cart uses importpng to convert PNG files into Picotron graphics. It does this once, in the background, and caches the results.

If you edit one of your PNGs, photo_carousel won't notice (afaik it's impossible to get last-edited time of PNGs in Picotron) Rename your file to generate a new cache entry, or delete /appdata/photo_carousel/cache.pod to regenerate the entire cache.

importpng is fast, but it's sometimes lacking in its ability to convert images into Picotron's palette. If you want better colors, you should use an external tool (like Aseprite) to convert your PNG into the base Picotron palette (you'll want the base palette, because the global palette changes to the base palette whenever you focus on some other window)

In the future I may use PNG Frame to get better colors by default, but I haven't done that work yet.

Transitions

You can add your own transitions -- you can skim through src/subdraw.lua without needing to understand anything else in the cart, and add new entries to the list of "subdraws" (transitions). Its very shadery/demosceney code

Many of the subdraws use some helper functions in src/tools.lua

Post your transition code here!

CPU usage

The cart uses about 0.002 cpu (0.2%) most of the time. During transitions, it can spike up to 25% cpu or so (depending on the transition). If you care, you can disable the transitions as a whole (by editing the settings) or individually (by editing the multi-line comments in src/subdraw.lua)

Cart

Here's the cart file. (It won't work here on the BBS, you need to download it)

photo_carousel

Cart File | Forum Post |

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photo_carousel

by pancelor

Cart #photo_carousel-1 | 2024-04-07 | Embed ▽ | License: CC4-BY-NC-SA

6

This app looks so awesome 🤩
I’d want to make a custom themed wallpaper set of the “stage out” of various monsters in Sailor Moon SuperS lol

Oh! btw is there a way for implementing this concept to “image slides”? You’d press spacebar and it switches to the next image until it comes back again to the first one; making a literal looping function?

Yes that's possible, but it doesn't make much sense to me in this wallpaper/screensaver context. I'd suggest writing a new cart that changes the current sprite drawn to the screen every time you press space, then store your "slides" in different sprites in the spritesheet. (you can use importpng to import pngs into the spritesheet)

@pancelor thanks for your insight, but I’ve did managed to get unstuck in this conundrum eventually.