compare

Helpers for validating geometry against expected areas and oracle fixtures (used in tests).

Imports

import {
  relativeAreaError,
  containmentAgreement,
  assertAreaClose,
  oraclePathsToGroup,
  ringsToPath,
  type OracleCase,
} from 'pattapatta'

Types

`OracleCase`

Fixture shape for oracle comparisons:

Field	Meaning
`id`	Case identifier
`seed`	RNG seed used to build the case
`operation`	Operation name under test
`outputs.paths`	Expected rings as `number[][][]` per path
`outputs.lines`	Expected open polylines
`outputs.circles`	Expected disks `{ x, y, r }`
`outputs.scalars`	Optional scalars (e.g. `area`)

Functions

Function	Description
`ringsToPath(rings)`	Convert `number[][][]` rings → closed `Path`
`oraclePathsToGroup(paths)`	Map oracle path rings → `Group`
`relativeAreaError(a, b)`	`\\|area(a) − area(b)\\| / max(\\|a\\|, \\|b\\|, ε)`
`assertAreaClose(actual, expectedArea, tol?)`	Throw if relative area error exceeds `tol` (default `1e-3`)
`containmentAgreement(a, b, samples?)`	Fraction of grid samples with matching point-in-group (default `20×20`)

Example

const got = union(a, b)
assertAreaClose(got, 150, 1e-3)
relativeAreaError(got, expected) // ~0 when areas match
containmentAgreement(got, expected, 16) // 1 when regions agree