Resolved merge conflicts:
- lib/Epub/Epub.h: Kept both upstream's cropped parameter and HEAD's thumb functions
- lib/JpegToBmpConverter/JpegToBmpConverter.cpp: Used upstream's version (dithering code moved to BitmapHelpers)
- src/activities/home/HomeActivity.cpp: Kept HEAD's comment about stack size
Added missing 1-bit dithering support to BitmapHelpers:
- Added Atkinson1BitDitherer class to BitmapHelpers.h
- Added quantize1bit() function to BitmapHelpers.cpp
1. Refactor Bitmap.cpp/h to expose the options for FloydSteinberg and
brightness/gamma correction at runtime
2. Fine-tune the thresholds for Floyd Steiberg and simple quantization
to better match the display's colors
Turns out that 2 is enough to make the images render properly, so the
brightness boost and gamma adjustment doesn't seem necessary currently
(at least for my test image).
Added a setting to select `fit` or `crop` for cover image on sleep
screen.
Might add a `expand` feature in the future that does not crop but rather
fills the blank space with a mirror of the image.
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
- Add 1-bit BMP generation with Atkinson dithering for better quality thumbnails
- Replace noise dithering with error diffusion for smoother gradients
- Add fillPolygon() to GfxRenderer for proper bookmark ribbon shape
- Change bookmark from rect+triangle carve to pentagon polygon
- Fix bookmark inversion when Continue Reading card is selected
- Show selection state on first render (not just after navigation)
- Fix 1-bit BMP palette lookup in Bitmap::readRow()
- Add drawBitmap1Bit() optimized path for 1-bit BMPs
The 1-bit format eliminates gray passes on home screen for faster rendering
while Atkinson dithering maintains good image quality through error diffusion.
## Summary
* Swap to updated SDCardManager which uses SdFat
* Add exFAT support
* Swap to using FsFile everywhere
* Use newly exposed `SdMan` macro to get to static instance of
SDCardManager
* Move a bunch of FsHelpers up to SDCardManager
## Summary
* **What is the goal of this PR?**
Replace simple threshold-based grayscale quantization with ordered
dithering using a 4x4 Bayer matrix. This eliminates color banding
artifacts and produces smoother gradients on e-ink display.
* **What changes are included?**
- Add 4x4 Bayer dithering matrix for 16-level threshold patterns
- Modify `grayscaleTo2Bit()` function to accept pixel coordinates and
apply position-based dithering
- Replace simple `grayscale >> 6` threshold with ordered dithering
algorithm that produces smoother gradients
## Additional Context
* Bayer matrix approach: The 4x4 Bayer matrix creates a repeating
pattern that distributes quantization error spatially, effectively
simulating 16 levels of gray using only 4 actual color levels (black,
dark gray, light gray, white).
* Cache invalidation: Existing cached `cover.bmp` files will need to be
deleted to see the improved rendering, as the converter only runs when
the cache is missing.
## Summary
* Builds on top of
https://github.com/daveallie/crosspoint-reader/pull/16 - adresses
https://github.com/daveallie/crosspoint-reader/discussions/14
* This PR adds the ability for the user to supply a custom `sleep.bmp`
image at the root of the SD card that will be shown instead of the
default sleep screen if present.
* Supports:
* Different BPPs:
* 1bit
* 2bit
* 8bit
* 24bit
* 32bit (with alpha-channel ignored)
* Grayscale rendering
---------
Co-authored-by: Sam Davis <sam@sjd.co>
