# Xiaomi Mi Reader E Ink compatibility library

The extracted `libfakeRKEpdUtils.so` exposes an EBC overlay path on every
packaged ABI. `JniCall_CommitOverlay` accepts an Android bitmap, a source
rectangle and a destination point. The native implementation locks the bitmap
pixels, converts the selected RGBA region to Gray4 and commits that region to
the EBC overlay. It does not require an Android `View` redraw.

Notable uses two paths. Live stylus samples are rasterized into the smallest
dirty bitmap and passed directly to `sCommitImage` once per display frame. On
pen-up, one delayed regional capture reconciles the overlay with Qt's retained
canvas. Full `View.draw()` capture is not used while the pen is moving.

The relevant exported native functions are `obtain_ebc_target`,
`commit_overlay`, `convertRGBAtoGray4`, `set_overlay_commit`,
`set_overlay_bg_control`, `clearOverlayColor` and `release_ebc_target`.