Architecture

univis_ui is organized around four main subsystems:

• layout/: layout solving and spatial computation
• interaction/: picking and interaction state
• widget/: ready-made UI widgets
• style/: fonts, icons, and shared theme resources

Core Idea

Everything in Univis is built from ECS entities and components:

• there is no external retained UI tree
• every UI element is an entity with UNode plus optional companion components
• layout, interaction, and rendering all run through Bevy systems

Standard Frame Flow

1. PreUpdate
   • the picking backend resolves hit entities
2. Update
   • widget logic, interaction logic, and visual state changes run here
3. PostUpdate
   • the layout pipeline runs:
     • update_layout_hierarchy
     • upward_measure_pass_cached
     • downward_solve_pass_safe
   • render and material sync systems apply visual output

Design Goals

• crisp visuals through SDF rendering
• flexible layout through Flex, Grid, Masonry, Stack, and Radial
• easy extension through ECS components and plugins
• debuggable performance through profiling and cache-aware systems