Er, forgot to answer your question re languages, I have not found a good one yet.
Best one so far has been Java with JavaFX which replaced Swing, it's a very large install.
But it comes already on Raspbian.
I keep checking the Automotive Linux sites for clues, Tizen stuff etc.
Seems most are based on QT + $$$$ libraries and C++.
On Pi's it is best to look for a GPU acceleration which JavaFX does.
Waiting for Wayland/Weston/Mesa etc to come out, hoping it might help.
After trying lots of methods I am moving to bare metal with Ultibo, won't get me GPU accelerated yet but it will be faster as there is no OS. It use Pascal which compiles much faster than C/C++, which makes it quicker to test stuff and it is tiny.
Spent a lot of time with these guys stuff, reading manuals etc.
Hope one day there will be a port of Vulkan to the Pi.
Best language would be one where the grunt stuff is done by the GPU and the Arm just runs simple scripts.
ie Arm reads the sensor data and passes the needle position to the GPU to render it.
May have to try the GPU compiler/assembler.
It is getting easier as more people reverse engineer the Videocore.
https://rpiplayground.wordpress.com/tag ... ry-pi-gpu/
https://petewarden.com/2014/08/07/how-t ... g-its-gpu/
As most of the Pi's OpenMAX stuff is C/C++ that would a starting point too, but it is mostly for video etc.
A language that talks OpenGL ES?
https://jan.newmarch.name/LinuxSound/Di ... yPiOpenGL/
Lots of coding that is not that easy to understand
A script language that talks to the Pi's 3D/2D GPU stuff.
Pi3D may be another option, uses python.
Some people have tried Kivy but I don't think with much success.
Yes TK/TCL has been around for ages, ok for GUI's?
Don't think it uses hardware acceleration.
Anything must run quick on the slower ones, don't want to use Pi3's just for this.
After all the GPU is the same from Zero to Pi3.
It would be nice if it can be themed, ie easy to change look and feel without recompiling.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges