Today I tried to use tuxpaint (0.9.21 as it comes with Fedora 18) on my Dell XPS 12 Ultrabook Convertible in Tablet mode (Input via Touchscreen).
In Fullscreen mode I get black borders around the window with full HD resolution.
Every touch to the screen is now set left and down by exact the width and height of the left and top border. I have to touch the screen at 0,0 to get the mouse pointer to the "window" at 0,0. Unfortunally the "window" is not at 0,0 of the screen but at x,y where x,y is the exact offset of every mouse click i get when i tap on the screen.