2 - JOF: The Jump-Offset Band-Tile Atlas
This is the format the whole e-reader rests on, and the one I would point at if somebody asked what is actually hard about rendering on a microcontroller.
The short version of the problem: the images this thing has to display are far larger than the RAM it has to display them with, and the formats they arrive in are built in a way that makes partial decoding impossible. Something has to give. This post is the longest in the series, and it sets up the vocabulary – index, seek, working set, edge clamp – that the rest reuse.
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