OK, some news.
1) I found my blatant mistake with awk: I didn't export variables used later in the awk. I found it just by manually trying to run the code line by line... Still working to finish the first draft of a functional code.
2) Now, I have no clue how to run different awk 'triggers' simultaneously. I need separate triggers for 'page forward', and 'page backward', at least. The brute force way in my mind is to run a separate script for each.
3) @NiLuJe, can you please support/crash my following idea:
— I found one of your projects to literally
"draw" clock on the screen.
— I am thinking that the frame of the progress bar (chapter and subchapter marks + the beginning and the end marks, maybe) is not changing from page to page. The only thing is changing, actually, is the current progress line.
— So, what if I draw the frame once at the script execution (when (sub)chapter locations are processed), then fbrab it and save as a png, and just draw it by fbink each time needed?
— The only potential obstacle now is whether transparency is supported in fbgrab/convert (or Kindle at all).
— At every page turn, I'd draw a) current progress fillers first, then b) on top of it, the frame with (sub)chapters marks with 'alpha channel gaps' in between. This way I'd save multiple loops for drawing the same (sub)chapter marks (and I don't know how to implement loops in the awk actions anyway
)
Thank you in advance!
I appreciate all your support
P. S. If no transparency is possible, I will attempt to make a rough progress bar, where the frame is drawn in a separate box from the progress bar...