What problem does it solve? Working on classic-wgl's physics and pathfinding systems requires understanding a dense set of interacting mechanisms — PhysicsProvider lifecycle, click/enter/exit dispatch, GJK collision tests, quadtree partitioning, and A* search — whose behavior is spread across multiple crates and easy to get wrong. ## Core Features & Use Cases - Physics Lifecycle Reference: Explains the exact per-frame sequence (resize_screen, begin_frame, perform_calls, update_hover) and the rules for collider registration, enabled state, and virtual colliders (mouse PID 0, selection PID 1). - Interaction Dispatch Semantics: Details click priority sorting, consumes_click pre-scan, enter/exit transition detection, and drag-selection rectangle handling. - Algorithm Internals: Covers the GJK simplex evolution, quadtree split/retrieval behavior, and the A* pathfinder including octile heuristic, vehicle footprint/slope/jump/turn-cost gates, and worker offloading. - Use Case: When adding a new clickable UI element or debugging why a vehicle path avoids a slope, consult this Skill to understand collider sync, dispatch ordering, and the vehicle pathfinding gates before modifying engine code. ## Quick Start Ask the AI to explain how click dispatch priority and consumes_click work in classic-wgl's PhysicsProvider before modifying a UI button's click handler.
