Struct FootprintSink 

pub struct FootprintSink<'a> { /* private fields */ }

A StampSink that measures the stamps passing through it and hands each one on.

The footprint counts every stamp, not every cell. A position the buffer behind it discards — outside its window — still moves the footprint, and so does a stamp the composition finds already decided: what is measured is how far the drawing reached, which is a fact of the traffic rather than of the picture that survived it. Accumulating before delegating is what makes those two the same question, and it is the whole of the rule this adapter carries.

Implementations

impl<'a> FootprintSink<'a>

pub fn new(sink: &'a mut dyn StampSink) -> Self

Wraps sink, so that every stamp written through this one is measured and then drawn.

pub fn footprint(&self) -> Option<Footprint>

The rectangle the stamps written through this sink reach, or None while none has been.

The answer is a value rather than a borrow, so a caller holds what it is given and may go on stamping and ask again.

Trait Implementations

impl StampSink for FootprintSink<'_>

fn stamp( &mut self, at: Pos, cell: Cell, mode: StampMode, owner: Option<ShapeId>, )

Writes cell at the absolute position at, under mode, recorded under owner.