Suggestion: Improve Launching Image Handling

[EctoOne]

So there is this Thread where someone asks for separate Images for the Arcade Emulators. After I installed some Ports over the last few days, I have kinda the same request for different images for Ports.
And i also lost my launching images a few times now, because I can't store them with all my other files on my USB Stick.

So I took a look at runcommand.sh today and found this code (which i think is responsible for image handling):

function show_launch() {
    local images=()
 
    if [[ "$IS_SYS" -eq 1 && "$USE_ART" -eq 1 ]]; then
        # if using art look for images in paths for es art.
        images+=(
            "$HOME/RetroPie/roms/$SYSTEM/images/${ROM_BN}-image"
            "$HOME/.emulationstation/downloaded_images/$SYSTEM/${ROM_BN}-image"
        )
    fi
 
    # look for custom launching images
    if [[ "$IS_SYS" -eq 1 ]]; then
        images+=(
            "$HOME/RetroPie/roms/$SYSTEM/images/${ROM_BN}-launching"
            "$CONF_ROOT/launching"
        )
    fi
    [[ "$IS_PORT" -eq 1 ]] && images+=("$CONFIGDIR/ports/launching")
    images+=("$CONFIGDIR/all/launching")
 
    local image
    local path
    local ext
    for path in "${images[@]}"; do
        for ext in jpg png; do
            if [[ -f "$path.$ext" ]]; then
                image="$path.$ext"
                break 2
            fi
        done
    done

Even thought, I'm not using nor have I tested it, I think there is already a problem with per Rom launching images. It only checks for the path from the build in scraper or an images folder inside a system folder.
With all the recent changes, adding video and marquee support, and planned upcoming features, grid view and carousel gamelist, i think that method is too unflexible. I myself have all my media files in separate subfolders (_boxart, _image (Mix Image from UXS), _marquee, _screenshot and _video) with the same name as the respective Rom without any suffix. With that, I can simply rename the folders to change what image type I want to show instead of search/replace the path in all gamelist.xml files.

• Now, I wish we could store the system launching images in its own folder, that can be moved to an USB device (or automatic by usbmount daemon). Kinda like it works with the splashscreen folder.
• Then the script should check first if there is an image for an specific emulator and then as fallback for a system image.
• Of course we still should keep the option to enable game launching images with the highest priority, but we should have some way to define the path and/or if a suffix is used.

If we had a dedicated folder for launching images, it would make it easier to make backups and/or to share them if we want.

Since I have no idea how to code, I hope someone else might improve this.