History of knot 1 change

In crates/backdrop/src/field.rs, lines 218–229 on 15d3f6f7871b9ba24296599a30f4188cde40d8831dff7bdaad16c717bfadd9f4. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 218,229:crates/backdrop/src/field.rs.