## Summary
* **What is the goal of this PR?**
This PR fixes bugs when using Copyparty as an OPDS server.
https://github.com/9001/copyparty?tab=readme-ov-file#opds-feeds
OPDS uses a query parameter `?opds` to differentiate between HTML
requests and OPDS requests for the same path. It also uses relative
paths in the responses instead of full paths. Crosspoint didn't handle
these two cases.
* **What changes are included?**
Fixes to the two issues above.
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
Here is some example XML from my Copyparty instance:
https://gist.github.com/philips/9ecec29dfb69ed0591b032f16e799675
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**< YES | PARTIALLY | NO
>**_
Partially. I used Claude code to write the fix. I am not a strong C++
programmer. But, I manually compiled and tested.
---------
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
## Summary
**What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
`DESTRUCTOR_CLOSES_FILE=1` is set in platformio.ini, which makes SdFat's
FsBaseFile destructor call close() automatically when a file goes out of
scope.
Three categories of file close calls remain untouched:
1. Close before Storage.remove() on the same path: ScreenshotUtil.cpp
closes the file before deleting it on write error. The remove might fail
if the file is still open.
2. Close before reopening the same variable: Epub.cpp writes a temp
NCX/nav file, closes it, then reopens it for reading. The
RecentBooksStore.cpp close before saveToFile() is the same pattern, it
rewrites the same file.
3. Close on member variables: BookMetadataCache.cpp (bookFile,
spineFile, tocFile), Section.cpp (file), XtcParser.cpp (m_file),
ZipFile.cpp (file). These persist beyond any single function scope, so
the destructor timing doesn't match the intended close point.
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**PARTIALLY**_
## Summary
**What is the goal of this PR?**
Replaced manual 1-bit BMP header logic in `Xtc::generateCoverBmp()` and
`Xtc::generateThumbBmp()` with calls to the existing `createBmpHeader()`
utility. Added a `BmpRowOrder` enum and param to support the top-down
row order of XTC cover images.
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**PARTIALLY**_
## Summary
Improves text antialiasing quality on the Xteink X3 (SSD1677) display to
bring it closer to X4 rendering quality. Addresses white lines through
letter strokes and ghosting artifacts during page turns and screen
transitions.
## Changes
### Display Driver (open-x4-sdk)
- Dedicated X3 grayscale LUTs with tuned VDL drive strengths for dark
gray (2 time units) and light gray (3 time units), with active GND hold
on non-gray transitions to prevent floating source crosstalk
- Tight scan timing: TP2/TP3 reduced to 1 (total gate-on 7 units vs 17),
minimizing parasitic charge leakage that caused white lines through
letter strokes
- Fast diff BB reinforcement: Added mild VDH reinforcing pulse to
lut_x3_bb_full so black pixels are actively driven during differential
refreshes, clearing gray residue/ghosting
- displayGrayBuffer() updated to use the dedicated gray LUT bank instead
of full refresh LUTs for X3
### Rendering Pipeline
- Re-enabled light gray rendering for X3 text and images, now safe with
dedicated gray LUTs providing proper 4-level gray
- Removed isLightGrayRestricted() gating that was limiting X3 to 3-level
gray
- Runtime display dimensions in DirectPixelWriter and ScreenshotUtil,
replaced hardcoded constants with runtime getters to support X3 792x528
resolution
### Note
The open-x4-sdk submodule references a commit on
juicecultus/community-sdk. A corresponding PR to
open-x4-epaper/community-sdk should be merged first so the submodule ref
resolves on upstream.
## Testing
Tested on physical X3 hardware. White lines through letters
significantly reduced, in-book ghosting improved via BB reinforcement,
antialiasing visually closer to X4 quality.
## AI Disclosure
Yes, AI was used to assist with the development of these changes.
---------
Replace hardcoded DISPLAY_WIDTH, DISPLAY_HEIGHT, and DISPLAY_WIDTH_BYTES
constants with runtime values from display object to support multiple
device models (X3 and X4) with different screen dimensions.
## Purpose
This PR includes some preparatory changes that are needed for an
upcoming performant CJK font feature. The changes have no impact on
render time and heap allocation for latin text. **Despite this, I think
these changes stand on their own as a better font
compression/decompression implementation.**
## Summary
- Font decompressor rewrite: Replaced the 4-slot LRU group cache with a
two-tier system — a page buffer (glyphs prewarmed before rendering
begins) and a hot-group fallback (last decompressed group retained for
non-prewarmed
glyphs).
- Byte-aligned compressed bitmap format: Glyph bitmaps within compressed
groups are now stored row-padded rather than tightly packed before
DEFLATE compression, improving compression ratios by making identical
pixel rows produce
identical byte patterns. Glyphs are compacted back to packed format on
demand at render time. Reduces flash size by 155 KB.
- Page prewarm system: Added `Page::collectText` and
`Page::getDominantStyle` to extract per-style glyph requirements before
rendering, and `GfxRenderer::prewarmFontCache` to pre-decompress only
the groups needed for the dominant style
— eliminating mid-render decompression for the common case.
- UTF-8 robustness fixes: `utf8NextCodepoint` now validates continuation
bytes and returns a replacement glyph on malformed input;
`ChapterHtmlSlimParser` correctly preserves incomplete multi-byte
sequences across word-buffer flush
boundaries rather than splitting them.
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**YES**_ Architecture and
design was done by me, refined a bit by Claude. Code mostly by Claude,
but not entirely.
## Summary
**What is the goal of this PR?**
This change avoids the pattern of creating a `std::string` using
`.substr` in order to compare against a file extension literal.
```c++
std::string path;
if (path.length() >= 4 && path.substr(path.length() - 4) == ".ext")
```
The `checkFileExtension` utility has moved from StringUtils to
FsHelpers, to be available to code in lib/. The signature now accepts a
`std::string_view` instead of `std::string`, which makes the single
implementation reusable for Arduino `String`.
Added utility functions for commonly repeated extensions.
These changes **save about 2 KB of flash (5,999,427 to 5,997,343)**.
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
## Summary
**What is the goal of this PR?**
Probable fix for #1118. `sanitizeFilename` was only passing through
ASCII characters from filenames. It now maintains valid UTF-8
codepoints, including non-ASCII multibyte sequences. Truncation happens
at a maximum number of bytes, rather than characters, to prevent
filenames with many multibyte sequences from unexpectedly exceeding
FAT32 limits.
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**YES, I described #1118
to Claude and it suggested sanitizeFilename as the likely cause**_
## Summary
fixing issue if book href are absolute url and not relative to the
server
## Additional Context
* Fixes
https://github.com/crosspoint-reader/crosspoint-reader/issues/632
* https://github.com/harshit181/RSSPub/issues/43
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**< PARTIALLY>**_
This PR unifies navigation handling & adds system-wide support for
continuous navigation.
## Summary
Holding down a navigation button now continuously advances through items
until the button is released. This removes the need for repeated
press-and-release actions and makes navigation faster and smoother,
especially in long menus or documents.
When page-based navigation is available, it will navigate through pages.
If not, it will progress through menu items or similar list-based UI
elements.
Additionally, this PR fixes inconsistencies in wrap-around behavior and
navigation index calculations.
Places where the navigation system was updated:
- Home Page
- Settings Pages
- My Library Page
- WiFi Selection Page
- OPDS Browser Page
- Keyboard
- File Transfer Page
- XTC Chapter Selector Page
- EPUB Chapter Selector Page
I’ve tested this on the device as much as possible and tried to match
the existing behavior. Please let me know if I missed anything. Thanks 🙏

---
Following the request from @osteotek and @daveallie for system-wide
support, the old PR (#379) has been closed in favor of this
consolidated, system-wide implementation.
---
### AI Usage
Did you use AI tools to help write this code? _**PARTIALLY**_
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
* Truncating chapter titles using utf8 safe functions (Cyrillic titles
were split mid codepoint)
* refactoring of lib/Utf8
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**< PARTIALLY >**_
## Summary
When uploading or downloading an updated ebook from SD/WebUI/OPDS with
same the filename the `.crosspoint` cache is not cleared. This can lead
to issues with the Table of Contents and hangs when switching between
chapters.
I encountered this issue in two places:
- When I need to do further ePub cleaning using Calibre after I load an
ePub and find that some of its formatting should be cleaned up. When I
reprocess the same book and want to place it back in the same location I
need a way to invalidate the cache.
- When syncing RSS feed generated epubs. I generate news ePubs with
filenames like `news-outlet.epub` and so every day when I fetch new news
the crosspoint cache needs to be cleared to load that file.
This change offers the following features:
- On web uploads, if the file already exists, the cache for that file is
cleared
- On OPDS downloads, if the file already exists, the cache for that file
is cleared
- There's now an action for `Clear Cache` in the Settings page which can
clear the cache for all books
Addresses
https://github.com/crosspoint-reader/crosspoint-reader/issues/281
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? PARTIALLY
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
Adds support for browsing and downloading books from a Calibre-web
server via OPDS.
How it works
1. Configure server URL in Settings → Calibre Web URL (e.g.,
https://myserver.com:port I use Cloudflare tunnel to make my server
accessible anywhere fwiw)
2. "Calibre Library" will now show on the the home screen
3. Browse the catalog - navigate through categories like "By Newest",
"By Author", "By Series", etc.
4. Download books - select a book and press Confirm to download the EPUB
to your device
Navigation
- Up/Down - Move through entries
- Confirm - Open folder or download book
- Back - Go to parent catalog, or exit to home if at root
- Navigation entries show with > prefix, books show title and author
- Button hints update dynamically ("Open" for folders, "Download" for
books)
Technical details
- Fetches OPDS catalog from {server_url}/opds
- Parses both navigation feeds (catalog links) and acquisition feeds
(downloadable books)
- Maintains navigation history stack for back navigation
- Handles absolute paths in OPDS links correctly (e.g.,
/books/opds/navcatalog/...)
- Downloads EPUBs directly to the SD card root
Note
The server URL should be typed to include https:// if the server
requires it - HTTP→HTTPS redirects may cause SSL errors on ESP32.
## Additional Context
* I also changed the home titles to use uppercase for each word and
added a setting to change the size of the side margins
---------
Co-authored-by: Dave Allie <dave@daveallie.com>