Add core logic to detect and offset parallel edges (multiple edges between
the same two nodes) to make them visually distinguishable.
Features:
- Detect parallel edges using groupParallelEdges() utility
- Calculate perpendicular offset for each edge in a parallel group
- Distribute edges evenly around the center line (±0.5, ±1, ±1.5, etc.)
- Apply offset to Bezier control points for smooth curved paths
- Base offset of 30px provides clear visual separation
Technical implementation:
- Added calculatePerpendicularOffset() to compute offset vectors
- Added calculateEdgeOffsetMultiplier() for even distribution
- Extended getFloatingEdgeParams() to accept offsetMultiplier parameter
- Added offsetMultiplier and parallelGroupSize to RelationData type
- Updated GraphEditor to detect parallel edges and assign offsets
- Updated CustomEdge to apply offsets when rendering
Design documents included:
- EDGE_OVERLAP_UX_PROPOSAL.md: Complete UX design and implementation plan
- EDGE_OVERLAP_VISUAL_GUIDE.md: Visual specifications and design tokens
All 517 tests pass.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
