Discussion
Once Papyrix has initialized a display driver it needs fancy software to generate visuals to display! Which may happen early in the boot sequence in order to show error messages.
So today I'm reading some of its support classes, leaving the central GfxRenderer class for tomorrow! Followed by some support libraries over the rest of the week.
A bitmap class decodes/validates bitmap headers, & applies an Atkinson or Floyd-Steinberg dithering via support classes.
1/?
This bitmap class also has several methods to read rows of pixels, with caching. And possibly reformatting the pixels with that dithering and/or grayscale conversion.
Also there's methods to read all rows in, reformat errors into human-legible names, etc.
A separate file implements a bitmap-serializer & image processing, to prepare an image for eink display. Whilst its headerfile implements the dithering formulas, tracking the difference what's displayed & the ideal image.
2/3?
There's some utility functions for locating, opening, & rendering a bitmap to represent a certain file. As well as utilities to aid generating such a "cover" image, though code specific to different filetypes need to perform the actual rendering.
There's an Ordered Dither class which consults a lookuptable for random noise to inject before reducing the colour-palette to next to nothing.
And...
3/3.2!
There's a routine for saving a bitmap to a file rescaled to certain dimensions with added Atkinson dither.
Atkinson dithering is what the original Apple Macintosh used, & is named after their talented computer-graphics engineer. Interesting to see it still being used today...
3.3/3.3 Fin for today!
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