Integrate SDK-based RTC and IMU backends as alternatives to direct hardware access. HalClock now attempts SDK RTC initialization and caches time values for reliability. HalTiltSensor adds SDK IMU backend with fallback logic. ClockOffsetActivity gains touch and swipe gesture support for field navigation.
Implements bottom-edge swipe-up gesture detection and delayed touch-select with tracking state. Adds isTouchTapCandidate() to distinguish taps from swipes. Includes LilyGo T5 S3 board configuration with USB CDC logging transport for boards where Serial operator bool reports false incorrectly.
Refactor UI font generation to support different rendering modes based on size. Small UI fonts (12pt) use 1-bit rendering for crisp display and reduced flash usage. Large UI fonts (14pt) now use 2-bit compressed rendering to stay smooth when scaled up on touch/high-density boards. Extract font generation logic into reusable generate_ui_font() function.
Removed the getFontXHeight method from GfxRenderer interface. Updated documentation to clarify that getFontCapHeight returns the 'H' glyph height for optical alignment, and improved the comment for getTextVisualCenterOffset to be more concise.
Implement orientation-aware icon rendering using freeink::Icon format that applies rotation transforms per-pixel. Add wasListScroll helper for touch-based list navigation with swipe gestures. Switch vertical centering from x-height to cap-height for better visual alignment with capital-led UI labels.
Introduces uiScale() method to apply per-board UI scaling based on device type (1.0 for button devices, >1 for touch devices to make UI elements finger-sized). Adds scaledMetrics member to store scaled theme metrics that are returned by getMetrics().
Simplify and clarify documentation for touch gesture detection (back gesture, item taps, long-press) and board detection flags. No functional changes, just improved comment readability.
Implements tap zones on touch devices for page back/forward navigation and press-and-hold actions, mirroring physical button behavior. Adds isXteinkDevice() helper to distinguish Xteink X3/X4 boards from touch devices. The sunlight fading fix setting is now exclusive to Xteink devices, while touch devices get the new touch reader controls toggle instead.
Implement touch-down event detection to provide immediate visual feedback when touching list items, mirroring button navigation behavior. Add long-press detection (500ms threshold) to distinguish between tap and hold gestures. Apply touch-down selection updates to file browser, home menu, and recent books activities.
Implements tapToLogical() to convert normalized touch coordinates to orientation-aware logical screen coordinates. Adds TouchRegistry hit testing for interactive UI elements and header back button. Touch gestures now work correctly across all screen orientations (Portrait, Landscape, etc.) by inverting the rotateCoordinates transform.
Add dynamic I2C bus selection for battery gauge to support boards with multiple I2C controllers (e.g., Sticky uses Wire1 to avoid conflicts with GT911 touch). Fix logging on ESP32-S3 USB-Serial-JTAG by using esp_rom_printf instead of Serial, which incorrectly reports disconnected state.
Replace hardcoded X3-specific I2C pins and frequencies with values from the active board profile. Add support for boards with I2C fuel gauges (X3, LilyGo, Sticky) and ADC-based battery sensing (X4, M5Paper). Skip ADC setup when batteryAdc is unassigned to prevent GPIO mux faults.
Prevent I2C pin collision on S3/ESP32 boards by skipping the X3/X4 fingerprint probe. The probe's I2C pins (GPIO20/0) conflict with onboard peripherals like the BQ27220 gauge and reconfigure strapping pins. Force deviceType to X4 for non-C3 builds.
Change SPI pre-claim logic to only apply on C3/Xteink hardware where EPD_* pins are hardcoded. Other boards (M5Paper, Sticky) need to initialize SPI from BoardConfig::ACTIVE pins to avoid incorrect pin assignments for display and SD card.
## Summary
This PR adds the [Libre Baskerville
](https://github.com/impallari/Libre-Baskerville) font family to the
fonts available for download in CrossPoint.
## Additional Context
Baskerville is a classic font family, widely available in some form or
the other in most ereaders and widely used in publishing and in the
academy.
Libre Baskerville is a libre (SIL Open Font License v1) implementation
of it, which makes it possible for CrossPoint to ship it without issues.

---
### AI Usage
Did you use AI tools to help write this code? _**NO**_
## Summary
Non-functional cleanup: `ChapterHtmlSlimParser::` prefix is redundant
when calling `applyDirectionToEntry` within `ChapterHtmlSlimParser`
methods.
---
### AI Usage
Did you use AI tools to help write this code? _**NO**_
## Summary
* **What is the goal of this PR?** Prevent heap memory exhaustion caused
by thousands of machine-generated anchor IDs injected by epub converters
like Kobo KePub.
* Fix#2292.
* **What changes are included?**
* **Element-type filter (Layer 1):** Introduced the
`isNonNavigableInlineElement()` function in `ChapterHtmlSlimParser.cpp`
to automatically skip recording IDs on `<span>` elements, as they are
purely inline wrappers used for tracking and lack navigable meaning.
* **Hard cap (Layer 2):** Added the `MAX_ANCHORS_PER_CHAPTER = 1024`
constant to act as a fallback safety net against unbounded heap growth
from unknown future ID-injection patterns on non-span elements.
* **TOC Safety net:** Ensured that IDs matching known Table of Contents
(TOC) entries explicitly bypass both the `<span>` filter and the
1024-anchor cap, guaranteeing that chapter page-break and core
navigation logic are never compromised.
---
### 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 >**_
Implements a reusable touch tap gesture in the top-left corner that maps to the Back button. The gesture is automatically integrated into wasPressed/wasReleased for Back button, making it available across all screens without per-activity code. Also fixes low-power CPU frequency floor to 80 MHz on PSRAM boards to prevent SD write and PSRAM instability caused by APB clock dropping below safe threshold.
## Summary
* **What is the goal of this PR?**
* Fix EPUBs where internal file references are written in URL-style
escaped form, like spaces appearing as `%20`, so the reader can find the
right files instead of treating those references as missing.
* **What changes are included?**
* Added a small shared helper that converts those escaped EPUB-internal
paths back into their normal filenames before we try to look them up.
* Applied that cleanup step across the EPUB parsing flow wherever we
resolve internal references, including cover images, manifest items, TOC
links, spine entries, and inline HTML images.
* Kept the change narrowly focused on EPUB-internal asset resolution
rather than changing broader URL or networking behavior.
## Additional Context
* The user-facing bug here is that some books package their internal
filenames in an escaped form, so a file like `Chapter 1.xhtml` may be
referenced more like `Chapter%201.xhtml`. The reader was treating that
escaped text as the literal filename, which means otherwise-valid books
could lose images, covers, or chapter targets because the lookup no
longer matched the real file inside the EPUB.
* Risk is intentionally low. The helper only rewrites valid `%XX` escape
sequences and leaves malformed input alone, so it should improve
compatibility with escaped filenames without broadening the parser’s
behavior in unrelated cases.
## Local Testing Performed
* This was tested on my device with the user-provided optimized epub
that was not rendering images within the text prior to this fix (cover
image and chapter headers were rendering fine):
[orv_main_baseline.epub.zip](https://github.com/user-attachments/files/28529545/orv_main_baseline.epub.zip)
* This was also tested by the user with a local build and the affected
epub and confirmed to be working
## Steps for Testing
* Try to open the affected epub (linked above) or any epub that has
similar percent-encoding on a build prior to this fix.
* Apply this fix, clear book cache, and re-open the affected book.
* Images should render properly.
---
### 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 >**_
## Summary
Use `std::string_view` and case-insensitive comparisons to avoid string
allocations during CSS parsing.
**Hot path:** `resolveStyle` (called per HTML start tag during chapter
rendering) now does zero heap allocations. Previously it allocated a
normalized tag string, a vector of class strings, and a composite key
per class. For a chapter with ~2000 tags × 2 classes each, that's ~12
000 small short-lived allocations eliminated per page render — primarily
a heap-fragmentation win on the ESP32-C3's ~380KB RAM.
**Cold path:** CSS load no longer allocates per-rule selector vectors or
per-token strings; `splitOnChar`/`splitWhitespace` are gone, replaced
with callback-based tokenization (`forEachDelimitedToken`).
**Behavioral notes:**
- The selector `unordered_map` now uses an ASCII-case-insensitive
hash/equal. Selectors are stored with their original case rather than
pre-lowercased; the observable lookup result is unchanged.
- `stripTrailingImportant` is now case-insensitive (per CSS spec;
previously matched only lowercase `!important`).
**Cache compatibility:** `CSS_CACHE_VERSION` unchanged. Old caches
(lowercase selectors) load correctly under the new lookup; new caches
will contain verbatim-case selectors — both forms work.
---
### AI Usage
Did you use AI tools to help write this code? _**PARTIALLY**_
## Summary
This PR optimizes the text rendering process by skipping underline style
calculations and measurements during the initial font cache scanning
phase. This prevents excessive and unnecessary SD card reads on pages
with heavy use of underlines (e.g., Table of Contents pages).
### **The Problem**
During the first rendering pass (the font cache scan pass used to
collect text for prewarming), `GfxRenderer::drawText()` early-returns
after recording text as expected. However, `TextBlock::render()`
continued past this point to execute the underline decoration logic.
Because underline calculation calls `getTextWidth()` and
`getTextAdvanceX()`, it triggered immediate glyph lookups via
`EpdFont::getGlyph()`. Since the SD card font had not been prewarmed yet
at this stage, the lookups fell back to the `glyphMissHandler`,
resulting in hundreds of individual, slow SD card reads into a limited
8-slot ring buffer.
### **The Fix**
1. **Exposed Scan State:** Added `GfxRenderer::isFontCacheScanning()` to
safely check if the font cache manager is currently in
text-collection/scan mode.
2. **Bypassed Underline Logic:** Modified `TextBlock::render()` to check
this state and skip underline measurement and drawing entirely while
scanning is active.
> [!NOTE]
> The text itself is still properly captured for prewarming via
`drawText()`. The underlines will be safely and efficiently calculated
and drawn during the actual render pass after the fonts have been
completely prewarmed.
---
### 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 >**_
## Summary
* **What is the goal of this PR?**
* This PR ports over Crossink's handling of large EPUBs that helps
prevent crashes during open after the book metadata cache is built.
* **What changes are included?**
* Removes the post-indexing ZIP-wide CSS discovery pass that built an
in-memory map of every ZIP entry.
* Reuses `content.opf` parsing to collect declared CSS files without
writing spine entries again.
* Temporarily releases the loaded book metadata cache while rebuilding
CSS for cached books.
* Parses CSS before reloading `book.bin` after a fresh cache build,
leaving more heap available during CSS rule parsing.
## Additional Context
* User reported their EPUB opening fine on Crossink but would crash on
Crosspoint. Verified this claim on my own devices.
* The crash this addresses happened after `book.bin` was successfully
built, when CSS discovery allocated a large `unordered_map` for ~3k EPUB
ZIP entries.
* Tradeoff: CSS files not declared in `content.opf` are no longer
discovered by scanning the full ZIP. This avoids the high-risk memory
allocation but improperly formatted EPUBs (ones that don't declare their
CSS styles in `content.opf` will render without styling and fallback to
inline styles.
* User provided epub that was crashing prior to this change:
https://www.mediafire.com/file/g57ea4mj13iunvh/Quang+%C3%82m+Chi+Ngo%E1%BA%A1i+-+Nh%C4%A9+C%C4%83n.epub/file
---
### 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 >**_