## Summary
* **What is the goal of this PR?** Address expected hyphenation issue
from
https://github.com/crosspoint-reader/crosspoint-reader/issues/998#issuecomment-3940533510
* Closes#998
* **What changes are included?** Add `„` (U+201E, _Double Low-9
Quotation Mark_), `‚` (U+201A, _Single Low-9 Quotation Mark_) and `‹`
(U+2039, _Single Left-pointing Angle Quotation Mark_) exceptions, other
quote types were handled correctly.
**Before**
<img width="480" height="155" alt="hyph3"
src="https://github.com/user-attachments/assets/e06b4071-2c8c-4814-965d-96fbe302a450"
/>
**After**
<img width="480" height="154" alt="hyph3-fix"
src="https://github.com/user-attachments/assets/4f7f5406-e200-451c-8bee-3f410cc84bbe"
/>
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
---
### AI Usage
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## Summary
**What is the goal of this PR?**
Consolidated repeated logic to fall back to REPLACEMENT_GLYPH.
---
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## Summary
* **What is the goal of this PR?**
A Ukrainian translation for the GUI
* **What changes are included?**
Everything according to
https://github.com/crosspoint-reader/crosspoint-reader/blob/master/docs/i18n.md
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
Nope
---
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Did you use AI tools to help write this code? _**< PARTIALLY >**_ as a
consistency validation
## Summary
* Remove miniz and move completely to uzlib
* Move uzlib interfacing to InflateReader to better modularise inflation
code
---
### AI Usage
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Did you use AI tools to help write this code? Yes, Claude helped with
the extraction and refactor
## Summary
* Resolve several build warnings
---
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## Summary
* This PR introduces a migration from binary file storage to JSON-based
storage for application settings, state, and various credential stores.
This improves readability, maintainability, and allows for easier manual
configuration editing.
* Benefits:
- Settings files are now JSON and can be easily read/edited manually
- Easier to inspect application state and settings during development
- JSON structure is more flexible for future changes
* Drawback: around 15k of additional flash usage
* Compatibility: Seamless migration preserves existing user data
## Additional Context
1. New JSON I/O Infrastructure files:
- JsonSettingsIO: Core JSON serialization/deserialization logic using
ArduinoJson library
- ObfuscationUtils: XOR-based password obfuscation for sensitive data
2. Migrated Components (now use JSON storage with automatic binary
migration):
- CrossPointSettings (settings.json): Main application settings
- CrossPointState (state.json): Application state (open book, sleep
mode, etc.)
- WifiCredentialStore (wifi.json): WiFi network credentials (Password
Obfuscation: Sensitive data like WiFi passwords, uses XOR encryption
with fixed keys. Note: This is obfuscation, not cryptographic security -
passwords can be recovered with the key)
- KOReaderCredentialStore (koreader.json): KOReader sync credentials
- RecentBooksStore (recent.json): Recently opened books list
3. Migration Logic
- Forward Compatibility: New installations use JSON format
- Backward Compatibility: Existing binary files are automatically
migrated to JSON on first load
- Backup Safety: Original binary files are renamed with .bak extension
after successful migration
- Fallback Handling: If JSON parsing fails, system falls back to binary
loading
4. Infrastructure Updates
- HalStorage: Added rename() method for backup operations
---
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---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
_Revision to @blindbat's #802. Description comes from the original PR._
- Replace `std::list` with `std::vector` for word storage in `TextBlock`
and `ParsedText`
- Use index-based access (`words[i]`) instead of iterator advancement
(`std::advance(it, n)`)
- Remove the separate `continuesVec` copy that was built from
`wordContinues` for O(1) access — now unnecessary since
`std::vector<bool>` already provides O(1) indexing
## Why
`std::list` allocates each node individually on the heap with 16 bytes
of prev/next pointer overhead per node. For text layout with many small
words, this means:
- Scattered heap allocations instead of contiguous memory
- Poor cache locality during iteration (each node can be anywhere in
memory)
- Per-node malloc/free overhead during construction and destruction
`std::vector` stores elements contiguously, giving better cache
performance during the tight rendering and layout loops. The
`extractLine` function also benefits: list splice was O(1) but required
maintaining three parallel iterators, while vector range construction
with move iterators is simpler and still efficient for the small
line-sized chunks involved.
## Files changed
- `lib/Epub/Epub/blocks/TextBlock.h` / `.cpp`
- `lib/Epub/Epub/ParsedText.h` / `.cpp`
## AI Usage
YES
## Test plan
- [ ] Open an EPUB with mixed formatting (bold, italic, underline) —
verify text renders correctly
- [ ] Open a book with justified text — verify word spacing is correct
- [ ] Open a book with hyphenation enabled — verify words break
correctly at hyphens
- [ ] Navigate through pages rapidly — verify no rendering glitches or
crashes
- [ ] Open a book with long paragraphs — verify text layout matches
pre-change behavior
---------
Co-authored-by: Kuanysh Bekkulov <kbekkulov@gmail.com>
## Summary
* This PR fixes decomposed diacritic handling end-to-end:
- Hyphenation: normalize common Latin base+combining sequences to
precomposed codepoints before Liang pattern matching, so decomposed
words hyphenate correctly
- Rendering: correct combining-mark placement logic so non-spacing marks
are attached to the preceding base glyph in normal and rotated text
rendering paths, with corresponding text-bounds consistency updates.
- Hyphenation around non breaking space variants have been fixed (and
extended)
- Hyphenation of terms that already included of hyphens were fixed to
include Liang pattern application (eg "US-Satellitensystem" was
*exclusively* broken at the existing hyphen)
## Additional Context
* Before
<img width="800" height="480" alt="2"
src="https://github.com/user-attachments/assets/b9c515c4-ab75-45cc-8b52-f4d86bce519d"
/>
* After
<img width="480" height="800" alt="fix1"
src="https://github.com/user-attachments/assets/4999f6a8-f51c-4c0a-b144-f153f77ddb57"
/>
<img width="800" height="480" alt="fix2"
src="https://github.com/user-attachments/assets/7355126b-80c7-441f-b390-4e0897ee3fb6"
/>
* Note 1: the hyphenation fix is not a 100% bullet proof implementation.
It adds composition of *common* base+combining sequences (e.g. O +
U+0308 -> Ö) during codepoint collection. A complete solution would
require implementing proper Unicode normalization (at least NFC,
possibly NFKC in specific cases) before hyphenation and rendering,
instead of hand-mapping a few combining marks. That was beyond the scope
of this fix.
* Note 2: the render fix should be universal and not limited to the
constraints outlined above: it properly x-centers the compund glyph over
the previous one, and it uses at least 1pt of visual distance in y.
Before:
<img width="478" height="167" alt="Image"
src="https://github.com/user-attachments/assets/f8db60d5-35b1-4477-96d0-5003b4e4a2a1"
/>
After:
<img width="479" height="180" alt="Image"
src="https://github.com/user-attachments/assets/1b48ef97-3a77-475a-8522-23f4aca8e904"
/>
* This should resolve the issues described in #998
---
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## Summary
* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
* The goal is to fix the title of books in the Home Screen.
Before

After:

* **What changes are included?**
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
---
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Did you use AI tools to help write this code? YES, Cursor
## Summary
* **What is the goal of this PR?**
* improve Spanish translations
* **What changes are included?**
- Fix typos and accents (Librería, conexión, etc.)
- Translate untranslated strings (BOOTING, SLEEPING, etc.)
- Improve consistency and conciseness
- Fix question mark placement (¿...?)
- Standardize terminology (Punto de Acceso, Suspensión, etc.)
---
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## Summary
* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
Add support for Catalan language user interface.
* **What changes are included?**
A new i18n file catalan.yml.
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
---
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Did you use AI tools to help write this code? NO
## Summary
* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
To add upport for a romanian language user interface.
* **What changes are included?**
A new i18n file `romanian.yml`
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
---
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## Summary
* Destroy CSS Cache file when invalid
## Additional Context
* Fixes issue where it would attempt to rebuild every book open
---
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## Summary
* In a sample book I loaded, it had 900+ CSS rules, and took up 180kB of
memory loading the cache in
* Looking at the rules, a lot of them were completely useless as we only
ever apply look for 3 kinds of CSS rules:
* `tag`
* `tag.class1`
* `.class1`
* Stripping out CSS rules with descendant, nested, attribute matching,
sibling matching, pseudo element selection (as we never actually read
these from the cache) reduced the rule count down to 200
## Additional Context
* I've left in `.class1.class2` rules for now, even though we
technically can never match on them as they're likely to be addressed
soonest out of the all the CSS expansion
* Because we don't ever delete the CSS cache, users will need to delete
the book cache through the menu in order to get this new logic
* A new PR should be done up to address this - tracked here
https://github.com/crosspoint-reader/crosspoint-reader/issues/1015
---
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## Summary
* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
When no width is set for an image, the image currently automatically
sets to the width of the page. However, with this fix, the parser will
use the height and aspect ratio of the image to properly set a height
for it. See below example:
Before:

After:

* **What changes are included?✱
Changes to the CSS parser
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
---
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## Summary
Fixes https://github.com/crosspoint-reader/crosspoint-reader/issues/1011
Use double FAST_REFRESH for image pages to prevent grayscale washout,
HALF_REFRESH sets e-ink particles too firmly for the grayscale LUT to
adjust, causing washed-out images (especially large, light-gray ones).
Replace HALF_REFRESH with @pablohc's double FAST_REFRESH technique:
blank only the image bounding box area, then re-render with images. This
clears ghosting while keeping particles loosely set for grayscale.
## Additional Context
---
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## Summary
* ``renderChar`` checked ``is2Bit`` on every pixel inside the inner
loop, even though the value is constant for the lifetime of a single
glyph
* Moved the branch above both loops so each path (2-bit antialiased /
1-bit monochrome) runs without a per-pixel conditional
* Eliminates redundant work in the two inner loops that render font
glyphs to the frame buffer, targeting ``renderChar`` and
``drawTextRotated90CW`` in ``GfxRenderer.cpp``
## Additional Context
* Measured on device using a dedicated framebuffer benchmark (no display
refresh). 100 repetitions of "The quick brown fox jumps".
| Test | Before | After | Change |
|-----------------|-----------------|-----------------|---------|
| drawText UI12 | 1,337 µs/call | 1,024 µs/call | −23%|
| drawText Bookerly14 | 2.174 µs / call | 1,847 µs/call | −15% |
---
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Did you use AI tools to help write this code? _**PARTIALLY**_ Claude did
the analysis and wrote the benchmarks
## Summary
The introduction of `HalGPIO` moved the `BatteryMonitor battery` object
into the member function `HalGPIO::getBatteryPercentage()`.
Then, with the introduction of `HalPowerManager`, this function was
moved to `HalPowerManager::getBatteryPercentage()`.
However, the original `BatteryMonitor battery` object is still utilized
by themes for displaying the battery percentage.
This PR replaces these deprecated uses of `BatteryMonitor battery` with
the new `HalPowerManager::getBatteryPercentage()` function.
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## Summary
* Increased `PNG_MAX_BUFFERED_PIXELS` from 6402 to 16416 in
`platformio.ini` to support up to 2048px wide RGBA images
* adds a check to abort decoding and log an error if the required PNG
scanline buffer exceeds the configured `PNG_MAX_BUFFERED_PIXELS`,
preventing possible buffer overruns.
* fixes
https://github.com/crosspoint-reader/crosspoint-reader/issues/993
---
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## Summary
* **What is the goal of this PR?**
I flashed the last revision before commit f1740dbe, and chapter indexing
worked without any crashes.
After applying f1740dbe, the same chapter consistently triggered a
device reboot during indexing.
The affected chapter contains inline equation images surrounded by
styled (bold/italic) text that includes special math/symbol characters.
## Additional Context
Prior to f1740dbe, both `getTextAdvanceX()` and `getSpaceWidth()` always
measured text using `EpdFontFamily::REGULAR`, regardless of the actual
style.
Commit f1740dbe improved correctness by passing the active style so
spacing is calculated using the actual bold/italic font variant.
However, bold and italic variants have narrower Unicode coverage than
the regular font. When a character exists in the regular font but not in
the selected styled variant, `pdFont::getGlyph()` returns `nullptr`.
The updated measurement functions did not check for this and immediately
dereferenced the pointer:
`width += font.getGlyph(cp, style)->advanceX; // nullptr->advanceX`
Because `advanceX` is located at byte offset 2 within `EpdGlyph`,
dereferencing a null pointer caused the CPU to attempt a load from
address `0x00000002`, resulting in a RISC-V:
Load access fault
MCAUSE = 5
MTVAL = 2
## Fix
Added null-safety checks to both `getTextAdvanceX()` and
`getSpaceWidth()`, following the same pattern used in the rendering
path:
If the glyph is missing in the selected style → fall back to the
replacement glyph.
If the replacement glyph is also unavailable → treat the character as
zero-width.
This preserves the improved style-correct spacing while preventing
crashes.
No behavioral changes occur for characters that are supported by the
selected font variant.
---
### AI Usage
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I encounter this bug while testing 1.1.0 RC.
I pasted the serial log to Claude, which identify the bug and fixed it.
I can confirm now the chapter in question is indexed and loaded
correctly.
I've been reading "Children of Time" over the last days and that book,
annyoingly, has some tabular content.
This content is relevant for the story so I needed some really basic way
to at least be able to read those tables.
This commit simply renders the contents of table cells as separate
paragraphs with a small header describing its position in the table. For
me, it's better than nothing.
## Summary
* **What is the goal of this PR?**
Implements really basic table support
* **What changes are included?**
* Minimal changes to ChapterHtmlSlimParser
* A demo book in test/epubs
## Additional Context
Here's some screenshots of the demo-book I provide with this PR.


---
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_Little bit of guidance on what to touch, parts of the impl, rest
manually._
## Summary
**What is the goal of this PR?**
* Implement feature request
[#954](https://github.com/crosspoint-reader/crosspoint-reader/issues/954)
* Ensure cover images are scaled up to match the dimensions of the
screen, as well as scaled down
**What changes are included?**
* Naïve implementation for scaling up the source image
## Additional Context
If you find the extra comments to be excessive I can pare them back.
Edit: Fixed title
---
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## Summary
* What is the goal of this PR?
- Allow users to create custom sleep screen images with standard tools
(ImageMagick, GIMP, etc.) that render cleanly on the e-ink display
without dithering artifacts. Previously, avoiding dithering required
non-standard 2-bit BMPs that no standard image editor can produce. ( see
issue #931 )
* What changes are included?
- Add 4-bit BMP format support to Bitmap.cpp (standard format, widely
supported by image tools)
- Auto-detect "native palette" images: if a BMP has ≤4 palette entries
and all luminances map within ±21 of the display's native gray levels
(0, 85, 170, 255), skip dithering entirely and direct-map pixels
- Clarify pixel processing strategy with three distinct paths:
error-diffusion dithering, simple quantization, or direct mapping
- Add scripts/generate_test_bmps.py for generating test images across
all supported BMP formats
## Additional Context
* The e-ink display has 4 native gray levels. When a BMP already uses
exactly those levels, dithering adds noise to what should be clean
output. The native palette detection uses a ±21 tolerance (~10%) to
handle slight rounding from color space conversions in image tools.
Users can now create a 4-color grayscale BMP with (imagemagic example):
```
convert input.png -colorspace Gray -colors 4 -depth
```
---
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## Summary
**What is the goal of this PR?**
`hasPrintableChars` does a pass over text before rendering. It looks up
glyphs in the font and measures dimensions, returning early if the text
results in zero size.
This additional pass doesn't offer any benefit over moving straight to
rendering the text, because the rendering loop already gracefully
handles missing glyphs. This change saves an extra pass over all
rendered text.
Note that both `hasPrintableChars` and `renderChar` replace missing
glyphs with `glyph = getGlyph(REPLACEMENT_GLYPH)`, so there's no
difference for characters which are not present in the font.
---
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## Summary
**What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
* Fixes:
https://github.com/crosspoint-reader/crosspoint-reader/issues/947
**What changes are included?**
* Check to see if there's free heap memory before processing CSS (should
we be doing this type of check or is it better to just crash if we
exhaust the memory?)
* Skip CSS files larger than 128kb
## Additional Context
* I found that a copy of `Release it` contained a 250kb+ CSS file, from
the homepage of the publisher. It has nothing to do with the epub, so we
should just skip it
* Major question: Are there better ways to detect CSS that doesn't
belong in a book, or is this size-based approach valid?
* Another question: Are there any epubs we know of that legitimately
include >128kb CSS files?
Code changes themselves created with an agent, all investigation and
write-up done by human. If you (the maintainers) would prefer a
different fix for this issue, let me know.
---
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## Summary
* GfxRender did handle horizontal and vertical lines but had a TODO for
arbitrary lines.
* Added integer based Bresenham line drawing
## Additional Context
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## Summary
* Original implementation had inconsistent positioning logic:
- When XPath parsing succeeded: incorrectly set pageNumber = 0 (always
beginning of chapter)
- When XPath parsing failed: used percentage for positioning (worked
correctly)
- Result: Positions restored to wrong locations depending on XPath
parsing success
- Mentioned in Issue #581
* Solution
- Unified ProgressMapper::toCrossPoint() to use percentage-based
positioning exclusively for both spine identification and intra-chapter
page calculation, eliminating unreliable XPath parsing entirely.
## Additional Context
* ProgressMapper.cpp: Simplified toCrossPoint() to always use percentage
for positioning, removed parseDocFragmentIndex() function
* ProgressMapper.h: Updated comments and removed unused function
declaration
* Tests confirmed appropriate positioning
* __Notabene: the syncing to another device will (most probably) end up
at the current chapter of crosspoints reading position. There is not
much we can do about it, as KOReader needs to have the correct XPath
information - we can only provide an apporximate position (plus
percentage) - the percentage information is not used in KOReaders
current implementation__
---
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## Summary
* **What is the goal of this PR?**
Add proper hyphenation support for the Ukrainian language.
* **What changes are included?**
- Added Ukrainian hyphenation rules/dictionary
## Additional Context
---
### AI Usage
Did you use AI tools to help write this code? _**NO**_
## Summary
**What is the goal of this PR?**
This change fixes an issue I noticed while reading where occasionally,
especially in italics, some words would have too much space between
them. The problem was that word width calculations were including any
negative X overhang, and combined with a space before the word, that can
lead to an inconsistently large space.
## Additional Context
Screenshots of some problematic text:
| In CrossPoint 1.0 | With this change |
| -- | -- |
| <img
src="https://github.com/user-attachments/assets/87bf0e4b-341f-4ba9-b3ea-38c13bd26363"
width="400" /> | <img
src="https://github.com/user-attachments/assets/bf11ba20-c297-4ce1-aa07-43477ef86fc2"
width="400" /> |
---
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## Summary
* During chapter parsing, every <img> tag triggered ZIP decompression
and an SD card write regardless of whether the image format was
supported. The mandatory delay(50) after each SD write compounded the
cost. A chapter with 6 GIF images (a common decorative element in older
EPUBs) wasted ~750 ms before any text rendering began.
* **What changes are included?**
Added an ``ImageDecoderFactory::isFormatSupported()`` check before any
file I/O in the img-handler. Only JPEG and PNG proceed to extraction;
all other formats (GIF, SVG, WebP, etc.) fall through immediately to
alt-text rendering with no SD card access.
## Additional Context
Measured impact on a representative chapter with 6 GIF decorations:
| | Before | After|
|-- | -- | --|
|Total parse time | ~882 ms | ~207 ms|
|Image handling | ~750 ms | ~76 ms|
---
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## Summary
**What is the goal of this PR?**
Compress reader font bitmaps to reduce flash usage by 30.7%.
**What changes are included?**
- New `EpdFontGroup` struct and extended `EpdFontData` with
`groups`/`groupCount` fields
- `--compress` flag in `fontconvert.py`: groups glyphs (ASCII base group
+ groups of 8) and compresses each with raw DEFLATE
- `FontDecompressor` class with 4-slot LRU cache for on-demand
decompression during rendering
- `GfxRenderer` transparently routes bitmap access through
`getGlyphBitmap()` (compressed or direct flash)
- Uses `uzlib` for decompression with minimal heap overhead.
- 48 reader fonts (Bookerly, NotoSans 12-18pt, OpenDyslexic) regenerated
with compression; 5 UI fonts unchanged
- Round-trip verification script (`verify_compression.py`) runs as part
of font generation
## Additional Context
## Flash & RAM
| | baseline | font-compression | Difference |
|--|--------|-----------------|------------|
| Flash (ELF) | 6,302,476 B (96.2%) | 4,365,022 B (66.6%) | -1,937,454 B
(-30.7%) |
| firmware.bin | 6,468,192 B | 4,531,008 B | -1,937,184 B (-29.9%) |
| RAM | 101,700 B (31.0%) | 103,076 B (31.5%) | +1,376 B (+0.5%) |
## Script-Based Grouping (Cold Cache)
Comparison of uncompressed baseline vs script-based group compression
(4-slot LRU cache, cleared each page). Glyphs are grouped by Unicode
block (ASCII, Latin-1, Latin Extended-A, Combining Marks, Cyrillic,
General Punctuation, etc.) instead of sequential groups of 8.
### Render Time
| | Baseline | Compressed (cold cache) | Difference |
|---|---|---|---|
| **Median** | 414.9 ms | 431.6 ms | +16.7 ms (+4.0%) |
| **Pages** | 37 | 37 | |
### Memory Usage
| | Baseline | Compressed (cold cache) | Difference |
|---|---|---|---|
| **Heap free (median)** | 187.0 KB | 176.3 KB | -10.7 KB |
| **Heap free (min)** | 186.0 KB | 166.5 KB | -19.5 KB |
| **Largest block (median)** | 148.0 KB | 128.0 KB | -20.0 KB |
| **Largest block (min)** | 148.0 KB | 120.0 KB | -28.0 KB |
### Cache Effectiveness
| | Misses/page | Hit rate |
|---|---|---|
| **Compressed (cold cache)** | 2.1 | 99.85% |
------
### 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**_
Implementation was done by Claude Code (Opus 4.6) based on a plan
developed collaboratively. All generated font headers were verified with
an automated round-trip decompression test. The firmware was compiled
successfully but has not yet been tested on-device.
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
## Summary
I want to preface this PR by stating that the proposed changes are
subjective to people's opinions. The following is just my suggestion,
but I'm of course open to changes.
The popups in the currently implemented version of the Lyra theme feel a
bit out of place. This PR suggests an updated version which looks a bit
more polished and in line with the rest of the theme.
I've also taken the liberty to remove the ellipsis behind the text of
the popups, as they made the popup feel a bit off balance (example
below).
With the applied changes, popups will look like this.

The vertical position is (more or less) aligned to be in line with the
sleep button. I'm aware the popup is used for other purposes aside from
the sleep message, but this still felt like a good place. It's also a
place where your eyes naturally 'rest'.
The popup has a small 2px white outline, neatly separating it from
whatever is behind it.
### Alternatives considered and rationale behind proposal
Initially I started out worked off the Figma design for the Lyra theme,
which [moves the
popups](https://www.figma.com/design/UhxoV4DgUnfrDQgMPPTXog/Lyra-Theme?node-id=2011-19296&t=Ppj6B2MrFRfUo9YX-1)
to the bottom of the screen. To me, this results in popups that are much
too easy to miss:

After this, I tried moving the popup back up (to the position of the
sleep button), but to me it still kinda disappeared into the text of the
book:

Inverting the colors of the popup made things stand out the perfect
amount in my opinion. The white outline separates the popup from what is
behind it.

This looked much better to me. The only thing that felt a bit off to me,
was the balance due to the ellipsis at the end of the popup text. Also,
"Entering Sleep..." felt a bit.. engineer-y. I felt something a bit more
'conversational' makes at all feel a bit more human-centric. But I'm no
copywriter, and English is not even my native language. So feel free to
chip in!
After tweaking that, I ended up with the final result:
_(Same picture as the first one shown in this PR)_

## Additional Context
* Figma design:
https://www.figma.com/design/UhxoV4DgUnfrDQgMPPTXog/Lyra-Theme?node-id=2011-19296&t=Ppj6B2MrFRfUo9YX-1
---
### 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
Continue my experiment from
https://github.com/crosspoint-reader/crosspoint-reader/pull/801
This PR add the ability to lower the CPU frequency on extended idle
period (currently set to 3 seconds). By default, the esp32c3 CPU is set
to 160MHz, and now on idle, we can reduce it to just 10MHz.
Note that while this functionality is already provided by [esp power
management](https://docs.espressif.com/projects/esp-idf/en/v4.3/esp32c3/api-reference/system/power_management.html),
the current Arduino build lacks of this, and enabling it is just too
complicated (not worth the effort compared to this PR)
Update: more info in
https://github.com/crosspoint-reader/crosspoint-reader/pull/852#issuecomment-3904562827
## Testing
Pre-condition for each test case: the battery is charged to 100%, and is
left plugged in after fully charged for an extra 1 hour.
The table below shows how much battery is **used** for a given duration:
| case / duration | 6 hrs | 12 hrs |
| --- | --- | --- |
| `delay(10)` | 26% | 48% |
| `delay(50)`, PR
https://github.com/crosspoint-reader/crosspoint-reader/pull/801 | 20% |
Not tested |
| `delay(50)` + low CPU freq (This PR) | Not tested | 25% |
| `delay(10)` + low CPU freq (1) | Not tested | Not tested |
(1) I decided not to test this case because it may not make sense. The
problem is that CPU frequency vs power consumption do not follow a
linear relationship, see
[this](https://www.arrow.com/en/research-and-events/articles/esp32-power-consumption-can-be-reduced-with-sleep-modes)
as an example. So, tight loop (10ms) + lower CPU freq significantly
impact battery life, because the active CPU time is now much higher
compared to the wall time.
**So in conclusion, this PR improves ~150% to ~200% battery use time per
charge.**
The projected battery life is now: ~36-48 hrs of reading time (normal
reading, no wifi)
---
### 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?**
Several methods in GfxRenderer were doing a `count()` followed by `at()`
on the fonts map, effectively doing the same map lookup unnecessarily.
This can be avoided by doing a single `find()` and reusing the iterator.
---
### 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?**
Skip constructing a `std::string` just to get the underlying `c_str()`
buffer, when a string literal gives the same end result.
---
### 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
This PR includes vocabulary and grammar fixes for Russian translation,
originally made as review comments
[here](https://github.com/crosspoint-reader/crosspoint-reader/pull/728).
---
### 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?**
This PR introduces Internationalization (i18n) support, enabling users
to switch the UI language dynamically.
**What changes are included?**
- Core Logic: Added I18n class (`lib/I18n/I18n.h/cpp`) to manage
language state and string retrieval.
- Data Structures:
- `lib/I18n/I18nStrings.h/cpp`: Static string arrays for each supported
language.
- `lib/I18n/I18nKeys.h`: Enum definitions for type-safe string access.
- `lib/I18n/translations.csv`: single source of truth.
- Documentation: Added `docs/i18n.md` detailing the workflow for
developers and translators.
- New Settings activity:
`src/activities/settings/LanguageSelectActivity.h/cpp`
## Additional Context
This implementation (building on concepts from #505) prioritizes
performance and memory efficiency.
The core approach is to store all localized strings for each language in
dedicated arrays and access them via enums. This provides O(1) access
with zero runtime overhead, and avoids the heap allocations, hashing,
and collision handling required by `std::map` or `std::unordered_map`.
The main trade-off is that enums and string arrays must remain perfectly
synchronized—any mismatch would result in incorrect strings being
displayed in the UI.
To eliminate this risk, I added a Python script that automatically
generates `I18nStrings.h/.cpp` and `I18nKeys.h` from a CSV file, which
will serve as the single source of truth for all translations. The full
design and workflow are documented in `docs/i18n.md`.
### Next Steps
- [x] Python script `generate_i18n.py` to auto-generate C++ files from
CSV
- [x] Populate translations.csv with initial translations.
Currently available translations: English, Español, Français, Deutsch,
Čeština, Português (Brasil), Русский, Svenska.
Thanks, community!
**Status:** EDIT: ready to be merged.
As a proof of concept, the SPANISH strings currently mirror the English
ones, but are fully uppercased.
---
### AI Usage
Did you use AI tools to help write this code? _**< PARTIALLY >**_
I used AI for the black work of replacing strings with I18n references
across the project, and for generating the documentation. EDIT: also
some help with merging changes from master.
---------
Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Co-authored-by: yeyeto2788 <juanernestobiondi@gmail.com>
This partially fixes#769 but is dependent upon PR #827 being merged
along side this @daveallie. I removed my PNG conversion code after
finding out that PR was already created. Without this PR though that
book in #769 will still fail to load because of how it's stored in the
file
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
- EPUB books with PNG cover images now display covers on the home screen
instead of blank rectangles
- Adds `PngToBmpConverter` library mirroring the existing
`JpegToBmpConverter` pattern
- Uses miniz (already in the project) for streaming zlib decompression
of PNG IDAT data
- Supports all PNG color types (Grayscale, RGB, RGBA, Palette,
Gray+Alpha)
- Optimized for ESP32-C3: batch grayscale conversion, 2KB read buffer,
same area-averaging scaling and Atkinson dithering as the JPEG path
## Changes
- **New:** `lib/PngToBmpConverter/PngToBmpConverter.h` — Public API
matching JpegToBmpConverter's interface
- **New:** `lib/PngToBmpConverter/PngToBmpConverter.cpp` — Streaming PNG
decoder + BMP converter
- **Modified:** `lib/Epub/Epub.cpp` — Added `.png` handling in
`generateCoverBmp()` and `generateThumbBmp()`
## Test plan
- [x] Tested with EPUB files using PNG covers — covers appear correctly
on home screen
- [ ] Verify with various PNG color types (most stock EPUBs use 8-bit
RGB)
- [ ] Confirm no regressions with JPEG cover EPUBs
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
**New Features**
- Added PNG format support for EPUB cover and thumbnail images. PNG
files are automatically processed and cached alongside existing
supported formats. This enhancement enables users to leverage PNG cover
artwork when generating EPUB files, improving workflow flexibility and
compatibility with common image sources.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Nik Outchcunis <outchy@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
* If an EPUB has:
```
<dc:creator>J.R.R. Tolkien</dc:creator>
<dc:creator>Christopher Tolkien</dc:creator>
```
the current result for epub.author would provide : "J.R.R.
TolkienChristopher Tolkien" (no separator!)
* The fix will seperate multiple authors: "J.R.R. Tolkien, Christopher
Tolkien"
## Additional Context
* Simple fix in ContentOpfParser - I am not seeing any dependence on the
wrong concatenated result.
---
### 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
This PR applies a micro optimization on `SerializedHyphenationPatterns`,
which allow reading `rootOffset` directly without having to parse then
cache it.
It should not affect storage space since no new bytes are added.
This also gets rid of the linear cache search whenever
`liangBreakIndexes` is called. In theory, the performance should be
improved a bit, although it may be too small to be noticeable in
practice.
## Testing
master branch:
```
english: 99.1023%
french: 100%
german: 97.7289%
russian: 97.2167%
spanish: 99.0236%
```
This PR:
```
english: 99.1023%
french: 100%
german: 97.7289%
russian: 97.2167%
spanish: 99.0236%
```
---
### 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 - mostly IDE
tab-autocompletions
## Summary
- Add embedded image support to EPUB rendering with JPEG and PNG
decoders
- Implement pixel caching system to cache decoded/dithered images to SD
card for faster re-rendering
- Add 4-level grayscale support for display
## Changes
### New Image Rendering System
- Add `ImageBlock` class to represent an image with its cached path and
display dimensions
- Add `PageImage` class as a new `PageElement` type for images on pages
- Add `ImageToFramebufferDecoder` interface for format-specific image
decoders
- Add `JpegToFramebufferConverter` - JPEG decoder with Bayer dithering
and scaling
- Add `PngToFramebufferConverter` - PNG decoder with Bayer dithering and
scaling
- Add `ImageDecoderFactory` to select appropriate decoder based on file
extension
- Add `getRenderMode()` to GfxRenderer for grayscale render mode queries
### Dithering and Grayscale
- Implement 4x4 Bayer ordered dithering for 4-level grayscale output
- Stateless algorithm works correctly with MCU block decoding
- Handles scaling without artifacts
- Add grayscale render mode support (BW, GRAYSCALE_LSB, GRAYSCALE_MSB)
- Image decoders and cache renderer respect current render mode
- Enables proper 4-level e-ink grayscale when anti-aliasing is enabled
### Pixel Caching
- Cache decoded/dithered images to `.pxc` files on SD card
- Cache format: 2-bit packed pixels (4 pixels per byte) with
width/height header
- On subsequent renders, load directly from cache instead of re-decoding
- Cache renderer supports grayscale render modes for multi-pass
rendering
- Significantly improves page navigation speed for image-heavy EPUBs
### HTML Parser Integration
- Update `ChapterHtmlSlimParser` to process `<img>` tags and extract
images from EPUB
- Resolve relative image paths within EPUB ZIP structure
- Extract images to cache directory before decoding
- Create `PageImage` elements with proper scaling to fit viewport
- Fall back to alt text display if image processing fails
### Build Configuration
- Add `PNG_MAX_BUFFERED_PIXELS=6402` to support up to 800px wide images
### Test Script
- Generate test EPUBs with annotated JPEG and PNG images
- Test cases cover: grayscale (4 levels), centering, scaling, cache
performance
## Test plan
- [x] Open EPUB with JPEG images - verify images display with proper
grayscale
- [x] Open EPUB with PNG images - verify images display correctly and no
crash
- [x] Navigate away from image page and back - verify faster load from
cache
- [x] Verify grayscale tones render correctly (not just black/white
dithering)
- [x] Verify large images are scaled down to fit screen
- [x] Verify images are centered horizontally
- [x] Verify page serialization/deserialization works with images
- [x] Verify images rendered in landscape mode
## Test Results
[png](https://photos.app.goo.gl/5zFUb8xA8db3dPd19)
[jpeg](https://photos.app.goo.gl/SwtwaL2DSQwKybhw7)








---
### AI Usage
Did you use AI tools to help write this code? _**< YES >**_
---------
Co-authored-by: Matthías Páll Gissurarson <mpg@mpg.is>
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
Closes#766. Thank you for the help @bramschulting!
**What is the goal of this PR?**
- First and foremost, fix issue #766.
- Through working on that, I realized the current CSS parsing/loading
code can be improved dramatically for large files and still had
additional performance improvements to be made, even with EPUBs with
small CSS.
**What changes are included?**
- Stream CSS parsing and reuse normalization buffers to cut allocations
- Add rule limits and selector validation to release rules and free up
memory when needed
- Skip CSS parsing/loading entirely when "Book's Embedded Style" is off
## Additional Context
- My test EPUB has been updated
[here](https://github.com/jdk2pq/css-test-epub) to include a very large
CSS file to test this out
---
### 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**_, Codex
## Summary
Closes#743.
**What is the goal of this PR?**
- Add back handling for HTML entities in expat. This was originally part
of the code that got removed
[here](https://github.com/crosspoint-reader/crosspoint-reader/pull/274)
- Handle ` ` characters to resolve issue #743
**What changes are included?**
- Brought back HTML entity table from previous commit and refactored it
to use a static const char * table with linear lookup to reduce heap
allocations.
- Used `XML_SetDefaultHandlerExpand` in expat to parse out the entities
correctly, without needing them defined in DOCTYPE
- Added handling for ` ` so that the text stays together and
doesn't break onto a new line with text separated by an ` `
## Additional Context
- This supersedes [this
PR](https://github.com/crosspoint-reader/crosspoint-reader/pull/751)
that simply handled `nbsp;` as whitespace. Instead, we want that
character to serve its true purpose and affect the line-breaking
algorithm.
- Updated my test EPUB [here](https://github.com/jdk2pq/css-test-epub)
with ` ` characters examples at the end of the book
---
### 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**_, Claude Code