Struct Obstacles 

pub struct Obstacles {
    rects: Vec<Block>,
    by_row: BTreeMap<i32, Vec<usize>>,
    by_col: BTreeMap<i32, Vec<usize>>,
}

The obstacle rectangles of a block, for the cheap “does a straight wire cross a block?” test that decides whether a leg can stay straight. Mirrors exactly the rects build_closed_router_for_block feeds to the router as blocks, so a straight leg judged clear here is the same one the router would leave alone — but without paying to build the routing graph (the point of the fast load path).

Rects are indexed by the rows and columns they span, so blocked/accessible only test the rects that could possibly hit the query line — not all of them. A linear scan here is quadratic across a whole document’s routes (each leg scans every block), which showed up as ~20s of load overhead at scale.

Fields

rects: Vec<Block>

by_row: BTreeMap<i32, Vec<usize>>

by_col: BTreeMap<i32, Vec<usize>>

Implementations

impl Obstacles

pub fn new(rects: Vec<ObstacleRect>) -> Self

pub fn blocked(&self, a: GridPoint, b: GridPoint) -> bool

Whether the axis-aligned wire a → b crosses any obstacle. Same result as ClosedRouter::is_wire_blocked, but only the rects spanning the wire’s row (horizontal wire) or column (vertical wire) are tested.

pub fn crossings( &self, a: GridPoint, b: GridPoint, ) -> impl Iterator<Item = (GridPoint, GridPoint)> + '_

Each stretch of the axis-aligned wire a → b that runs through an obstacle — what Self::blocked refuses, located.

pub fn hugs(&self, a: GridPoint, b: GridPoint) -> bool

Whether the axis-aligned wire a → b hugs any obstacle (runs alongside an edge within the routing gutter).

A hugging wire runs beside an edge rather than over it, so the index is queried a gutter wide either side of the wire: a rect with an edge within ROUTE_GUTTER of row y spans one of the rows y-gutter ..= y+gutter, and so is in one of their buckets. A rect spanning several of them is tested more than once, which costs less than the dedup would.

pub fn accessible(&self, p: GridPoint) -> bool

Whether p lies outside every obstacle (a waypoint inside one is dropped).

impl Obstacles

pub fn reroute_blocked(&self) -> LegRules<'_>

The rider’s rules: a leg through a block is routed again.

pub fn keep_blocked(&self) -> LegRules<'_>

A reconstruction’s rules: a leg through a block is kept as the document has it.