FluidCore v1.1.3 — Excerpt Card Resizing, Smooth Bézier Inking, Layer Stacking, & Memory Remediation

FluidCore v1.1.3 — Excerpt Card Resizing, Smooth Bézier Pen Inking, Layer Stacking, & Comprehensive Memory Remediation

FluidCore v1.1.3 delivers high-impact slice-of-life usability enhancements, inking rendering fidelity upgrades, and deep architectural memory leak remediations:

1. Interactive Excerpt Card Resizing: Resize text and visual crop excerpt cards with live high-resolution rasterization, strict aspect-ratio locking for visual crops, and full Undo/Redo integration.
2. Silky-Smooth Canvas Pen Inking: Eliminates low-pixel faceting, jagged lines, and polygonal clipping on tight circles and loops via curvature-adaptive deadzone scaling and centripetal Catmull–Rom Bézier spline interpolation.
3. Highlighter Layer Stacking: Highlighter strokes always render cleanly beneath solid pen strokes across both the PDF Document Reader and the Infinite Spatial Workspace canvas.
4. PDF Page Position Persistence: Projects now remember and automatically restore the active PDF reading page across saves and reloads, backed by an idempotent SQLite schema migration.
5. Comprehensive Memory Leak Remediation: Root-cause resolution of MinGW winpthread mutex retention via native Win32 CRITICAL_SECTION patching, ephemeral background search workers, and mimalloc heap slack reclamation.
6. Linux Distribution Packaging & ABI Portability Fix: Re-targeted Linux CI and release packagers to Ubuntu 22.04 LTS (GLIBC 2.35), statically linked C++ runtime (-static-libgcc -static-libstdc++), and refined library bundling in AppImage/.deb to eliminate GLIBC_2.38 and GLIBCXX_3.4.31 launch errors.

---

🌟 What's New in v1.1.3

1. Interactive Excerpt Card Resizing

• Intuitive Visual Grab Handles:
  • Hovering over or selecting any excerpt card reveals a 14 px circular grab handle at the bottom-right corner.
  • Contextual cursor updates to se-resize (GDK_BOTTOM_RIGHT_CORNER) upon hover.
• Strict Aspect-Ratio Locking for Visual Crop Cards:
  • Image crop cards automatically lock and preserve their original $(W:H)$ aspect ratio:
    $$\text{scale} = \max\left(\frac{W_0 + \Delta x}{W_0},, \frac{H_0 + \Delta y}{H_0}\right), \quad W = \text{clamp}(W_0 \cdot \text{scale}, 160, 1600), \quad H = \frac{W}{AR}$$
  • As visual cards enlarge or shrink, the excerpt image dynamically scales to fit the card geometry without any distortion or letterboxing.
• Full Undo / Redo Support (Ctrl+Z / Ctrl+Y):
  • Backed by the newly implemented ResizeNodeCommand in libfluidcore.
  • Seamlessly pushes commands to the undo stack upon mouse release, with automatic R-Tree spatial index recalculation.
• Dynamic Tile Cache Invalidation:
  • Upon completing a card resize, the excerpt tile cache automatically invalidates and re-renders the underlying PDF region at the new scale, ensuring vector-sharp clarity even at large expansions.

2. Silky-Smooth Canvas Pen Inking & Anti-Faceting Engine

• Curvature-Adaptive Deadzone Filtering:
  • Previous fixed-distance stabilization deadzones ($1.5$–$2.0$ px) truncated sharp directional changes, turning small loops and circles into faceted polygons at low pixel widths (1–2 px).
  • The new StrokeStabilizer measures the turning angle between successive stroke vectors:
    $$\cos \theta = \frac{\Delta \vec{v}{i} \cdot \Delta \vec{v}{i-1}}{|\Delta \vec{v}{i}| , |\Delta \vec{v}{i-1}|}$$
  • When a sharp turn or circle is detected ($\cos \theta < 0.95$), the deadzone automatically scales down to $0.15$ px, preserving tight curves and circular handwriting with zero polygonal flattening.
• Centripetal Catmull–Rom Bézier Splines:
  • Replaced linear segment chaining with centripetal Catmull–Rom cubic Bézier splining across both committed canvas strokes and live in-flight wet ink.
  • Live wet ink and committed nodes evaluate 4-step sub-segment Bézier curves with smooth pressure interpolation via evalCubicBezier, eliminating visual "popping" or snapping upon pen-up.

3. True Layer Stacking: Highlighter Sits Beneath Pen

• PDF Document Overlay (InkOverlay):
  • Split rendering into a two-pass compositor: Pass 1 renders all highlighter strokes in semi-transparent mode (CAIRO_OPERATOR_OVER); Pass 2 renders solid ink pens directly on top.
• Infinite Spatial Workspace Canvas (WorkspaceRenderer):
  • Re-architected canvas layer stacking order:
    1. Excerpt Cards, Stacks, and Structural Elements
    2. Committed Highlighter Strokes
    3. Active Wet Inking Highlighter Stroke
    4. Committed Pen Strokes
    5. Active Wet Inking Pen Stroke
    6. Selection Rings, Grab Handles, and Connectors
  • Highlighting over existing writing or sketching never dims, occludes, or muddies pen strokes.

4. PDF Reading Position Persistence Across Project Reloads

• Zero-Friction Context Restoration:
  • Saving a project (Ctrl+S) records the exact PDF page currently visible in the document reader viewport.
  • Reopening the .ltproj project bundle automatically scrolls the document reader directly to that page once dimensions and layout are computed.
• Idempotent SQLite Schema Migration:
  • Added last_viewed_page INTEGER NOT NULL DEFAULT 0 to the documents table in ProjectStore.
  • Uses PRAGMA table_info(documents) inspection prior to running ALTER TABLE, guaranteeing seamless, idempotent upgrades of existing project databases without throwing duplicate column errors.

5. Deep Memory Leak Remediation & Architecture Hardening

• Native Win32 CriticalSection Remediations:
  • Diagnosed and resolved a subtle memory retention bug in MinGW-w64's winpthread library, where std::mutex allocations bypassed standard CRT cleanup upon thread termination.
  • Applied native Win32 CRITICAL_SECTION fallbacks in ops/patches/poppler_win32_critical_section.patch for rock-solid concurrency stability.
• Ephemeral Background Search Document Lifecycle:
  • Document search workers now utilize an ephemeral PopplerDocument lifecycle and scheduled worker thread recycling (every 8 searches), releasing page descriptor caches immediately upon search completion.
• mimalloc Hardened Heap Management:
  • Linked mimalloc across fluidcore_app with PurgeDelay=0 and active decommit flags to aggressively return unmapped virtual memory slack directly to Windows.
  • Added internal live memory telemetry (MemoryTelemetry.h) and telemetry monitoring scripts in debug/scripts/.

6. Linux Distribution Packaging & ABI Portability Hardening

• Universal GLIBC 2.35+ Compatibility:
  • Re-targeted GitHub Actions release and packaging runners from ubuntu-24.04 to ubuntu-22.04.
  • Releases are now built against GLIBC 2.35, resolving runtime failures (version GLIBC_2.38 not found) on Ubuntu 22.04 LTS, Debian 12, Linux Mint 21, and other enterprise distributions, while maintaining forward compatibility with Ubuntu 24.04+.
• Static C++ Runtime Linking (-static-libgcc -static-libstdc++):
  • Statically linked libstdc++ and libgcc into fluidcore_app on Linux, eliminating GLIBCXX_3.4.xx runtime version mismatches.
• AppImage & Debian Package Refinements:
  • Updated package-appimage.sh excludelist to prevent bundling libstdc++/libgcc_s which could shadow newer host GPU display drivers.
  • Enhanced package-deb.sh dependencies with libpoppler-glib8 (>= 20.0) | libpoppler-glib8t64 for seamless installation across both Ubuntu 22.04 and Ubuntu 24.04 (t64 transition).

---

📦 Downloads & Binaries

Platform	Package	Format	File Name	Description
Windows	Native Installer	.exe	FluidCore-Setup-x64.exe	Recommended for Windows. Inno Setup 64-bit installer with Start Menu integration, desktop shortcut, uninstaller, and .ltproj project associations.
Windows	Portable Zip	.zip	fluidcore-windows-x64.zip	Standalone portable archive containing all required UCRT64 runtime DLLs, GLib schemas, GDK-Pixbuf loaders, and Adwaita icons. Run anywhere without admin privileges.
Linux	Debian Package	.deb	fluidcore_1.1.3_amd64.deb	Native Debian/Ubuntu package (apt install ./fluidcore_1.1.3_amd64.deb) with system dependency management and FreeDesktop menu entry.
Linux	AppImage Bundle	.AppImage	FluidCore-1.1.3-x86_64.AppImage	Recommended for Linux. Standalone portable executable with bundled dependencies and Wayland/X11 support. Run anywhere (chmod +x).

---

🧪 Verification & Test Suite Summary

• 100% CTest Suite Passing: All 39/39 unit and integration test suites pass with zero failures:
  • ProjectStoreTest: Validates lastViewedPage persistence round-trip and idempotent schema migration.
  • UndoStackTest: Validates ResizeNodeCommand execution, undo, redo, and spatial R-Tree index bounding box updates.
  • StrokeStabilizerTest: Validates adaptive curvature deadzone scaling on high-frequency directional turns.
  • PopplerMalformedRegressionTest & PopplerConcurrencyTest: Validates thread safety and memory bounds.
• Invariants Gate: python ops/scripts/check_invariants.py passed (zero runtime network calls, strict libfluidcore engine boundary).
• Code Style Compliance: 100% compliant with clang-format --dry-run --Werror.