thi-ng/umbrella

import type { FnU } from "@thi.ng/api";
import type { MatOpMV, ReadonlyMat } from "@thi.ng/matrices";
import { mulV } from "@thi.ng/matrices/mulv";
import type { ReadonlyVec, Vec } from "@thi.ng/vectors";
import type {
    IShape2,
    IShape3,
    PathSegment,
    PathSegment2,
    TransformVertexFn,
} from "../api.js";

/** @internal */
export const __transformedPoints = (
    pts: ReadonlyVec[],
    mat: ReadonlyMat,
    op: MatOpMV = mulV
) => pts.map((p) => op([], mat, p));

/** @internal */
export const __transformedPointsWith = (
    pts: ReadonlyVec[],
    fn: TransformVertexFn,
    op: MatOpMV = mulV
) => pts.map((p) => op([], fn(p), p)!);

// path segments

type SegmentShapeMap<T extends PathSegment> = T extends PathSegment2
    ? IShape2
    : IShape3;

/** @internal */
export const __segmentTransformer =
    <S extends PathSegment>(
        txGeo: FnU<SegmentShapeMap<S>>,
        txPoint: FnU<Vec>
    ) =>
    (segments: S[]) =>
        segments.map(
            (s): S =>
                s.geo
                    ? <any>{
                            type: s.type,
                            geo: txGeo(<any>s.geo),
                      }
                    : s.point
                    ? <S>{
                            type: s.type,
                            point: txPoint(s.point),
                      }
                    : <S>{ ...s }
        );