Displaying message on top of RetroArch

[RicardoJeronimo]

So, for a university project, I'm building an arcade cabinet and one of its features is the ability to unlock more gametime via QR code. With Android and Python I was able to make it work by pausing the RetroArch process with pkill -stop.

Now I want to display a message (or image) on top of RetroArch saying something like "Insert Coin", however, after many hours of research, I still haven't found a proper way to do it. Fbi runs on the terminal behind RetroArch and so do the demo programs located on /opt/vc/src/hello_pi.

Is there any way to achieve this, either by overlapping a message or even minimizing the RetroArch process?

[mitu]

@ricardojeronimo Instead of overlaying RetroArch, why not use it to show your message ? RA has a network (UDP) input interface, that you can send messages to. You could extend this interface with a new function (print "my Message"), then use the RA code to show text using the OSD sub-system (i.e. like RetroAchievements do).

[RicardoJeronimo]

@mitu That's really interesting. Does it involve changing and recompiling the actual RetroArch code?

[mitu]

@ricardojeronimo said in Displaying message on top of RetroArch:

Does it involve changing and recompiling the actual RetroArch code?

You bet it is - doesn't that sound challenging ? Or use the LED Api to blink some lights on your Raspberry PI. You could contribute back your code to RA (a new UDP network function and a new OSD function - if one does not already exist).

[RicardoJeronimo]

@mitu I guess the most challenging part of it all is learning how RetroArch works and how the code is laid out. Even though I already have a 7-segment display blinking "00:00" when time runs out, I think it's worth the effort

[RicardoJeronimo]

For anyone wondering, I got it working using Raspidmx PNGView: ./pngview -b 0 -l 10000 file.png

I set the layer to 10000 so it overlaps EmulationStation as well as RetroArch