containsPoint

function containsPoint(  region: PlaneRegion, ,  point: PlanePoint,): boolean;

Each path is treated as a closed polygon (the last point connects back to the first, so a repeated closing point is optional) and every path toggles inside/outside. A path nested inside another therefore cuts a hole, which matches the compound paths returned by plane queries and region booleans and SVG fill-rule="evenodd". Coordinates are compared as-is, so region and point must share a space (plane-normalized [0, 1] for query results). Points exactly on an edge may resolve either way.

Parameters

regionPlaneRegion

Region whose paths form one compound polygon.

pointPlanePoint

Point to test, in the same coordinate space as region.

Returns

booleantrue when the point is inside an odd number of paths.

Example

import { containsPoint } from '@pbroom/color-kit/plane';

const outer = [{ x: 0, y: 0 }, { x: 1, y: 0 }, { x: 1, y: 1 }, { x: 0, y: 1 }];
const hole = [{ x: 0.25, y: 0.25 }, { x: 0.75, y: 0.25 }, { x: 0.75, y: 0.75 }, { x: 0.25, y: 0.75 }];
const frame = { paths: [outer, hole] };

containsPoint(frame, { x: 0.1, y: 0.1 }); // → true
containsPoint(frame, { x: 0.5, y: 0.5 }); // → false (inside the hole)

See also

Also exported from

• @pbroom/color-kitthe same declaration, re-exported