thi-ng/umbrella

// thing:export
import type { Maybe } from "@thi.ng/api";
import { isNumber } from "@thi.ng/checks/is-number";
import { DEFAULT_SAMPLES } from "@thi.ng/geom-resample/api";
import { TAU } from "@thi.ng/math/api";
import type { ReadonlyVec } from "@thi.ng/vectors";
import type { Attribs, HiccupPathSegment, SamplingOpts } from "../api.js";

/** @internal */
export const __circleOpts = (
    opts: number | Partial<SamplingOpts>,
    r: number
): [number, number, boolean] =>
    isNumber(opts)
        ? [opts, 0, false]
        : [
                opts.theta
                    ? Math.floor(TAU / opts.theta)
                    : opts.dist
                    ? Math.floor(TAU / (opts.dist / r))
                    : opts.num || DEFAULT_SAMPLES,
                (opts.start || 0) * TAU,
                opts.last === true,
          ];

/**
 * @param opts
 * @param attribs
 *
 * @internal
 */
export const __sampleAttribs = (
    opts?: number | Partial<SamplingOpts>,
    attribs?: Attribs
): Maybe<number | Partial<SamplingOpts>> => {
    if (attribs) {
        const val = attribs.__samples;
        return isNumber(opts)
            ? isNumber(val)
                ? val
                : { num: opts, ...val }
            : isNumber(val)
            ? { ...opts, num: val }
            : { ...opts, ...val };
    }
    return opts;
};

export const __hiccupLineSegment = (
    a: ReadonlyVec,
    b: ReadonlyVec
): HiccupPathSegment =>
    a[0] === b[0] ? ["V", b[1]] : a[1] === b[1] ? ["H", b[0]] : ["L", b];