GitLab

Major enhancements:
- Web interface: PHP-based UI for Gerber/bitmap upload with AJAX progress
- Performance: 5-10× speedup via rectangle decomposition (O(DPI²) → O(DPI))
- Configuration: Flexible config system with local overrides
- Model height: 0.01-20mm range for SLA printing layer control

Web Interface Features:
- Dual mode: Gerber files + optional drill / Bitmap upload
- Real-time AJAX conversion with progress updates
- Configurable parameters: resolution (DPI), model height, units, format
- File downloads: STL, BMP, TIFF outputs
- Auto-cleanup: Configurable file retention with cron support
- Apache deployment ready with example configs

Performance Optimization:
- Scanline rectangle decomposition: Converts bitmap to rectangles
- Fast O(n log n) merging: Reduces rectangle count via sorting
- Result: UI.03.GBL at 300 DPI: 12 seconds (was ~600 seconds)
- Result: Simple boards at 600 DPI: <0.1 seconds
- Linear scaling with resolution instead of quadratic

Technical Implementation:
- New mesh_generator_optimized.c with rectangle-based meshing
- Region decomposer with scanline algorithm
- Fast rectangle merger using qsort
- Proper triangle normals (top/bottom caps + side walls)
- Experimental diagonal detection (disabled by default - too slow)

Configuration System:
- config.php: Base configuration with defaults
- config.local.php: Local overrides (git-ignored)
- Supports: binary path, work directories, timeouts, constraints
- Production-ready with security best practices

Documentation:
- Performance benchmarks and analysis
- Deployment guides and checklists
- API documentation for web interface
- Algorithm explanations and results

Validated with production PCB files at 300-600 DPI.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>