[Tutor] Text Directly to Screen?

[Alan Gauld]

> > What I want to do is output text *directly* to the screen. 

On Unix it is very platform specific. On a PC (including Linux) 
you could do it from assembler by writing direct to the screen 
memory map via the BIOS but that would probably break all the 
other stuff since the OS does a pile of mapping from the original 
memory area to the graphics card and in Windows it writes direct 
to the graphics card, so  the direct memory writes may not even 
work at all! In fact in NT/W2K/XP I suspect they wouldn't.

If you want to get really technical and low level in X Windows 
you could define a transparent window with no decorations that 
filled the screen. Writing to that would have the desired effect.

A similar technique may be possible in Win32 but I have no idea 
how to do it, never had to get that far down into the API. In 
either case it will require a lot of code to manage the window 
securely and allow it to operate without messing up the others 
underneath. - You would have to map all mouse movements and 
focus keystrokes to pass them to the underlying windows.

If anyone knows of an easier route I'll be interested to see it.

Alan G.