@thi.ng/geom-axidraw/as-axidraw.js

Conversion and preparation of thi.ng/geom shapes & shape groups to/from AxiDraw pen plotter draw commands

import { DOWN, MOVE, UP } from "@thi.ng/axidraw/commands";
import { polyline } from "@thi.ng/axidraw/polyline";
import { defmulti } from "@thi.ng/defmulti/defmulti";
import { clipPolylinePoly } from "@thi.ng/geom-clip-line/clip-poly";
import { pointInPolygon2 } from "@thi.ng/geom-isec/point";
import { applyTransforms } from "@thi.ng/geom/apply-transforms";
import { asPolyline } from "@thi.ng/geom/as-polyline";
import { __dispatch } from "@thi.ng/geom/internal/dispatch";
import { __sampleAttribs } from "@thi.ng/geom/internal/vertices";
import { withAttribs } from "@thi.ng/geom/with-attribs";
import { mapcat } from "@thi.ng/transducers/mapcat";
import { takeNth } from "@thi.ng/transducers/take-nth";
import { pointsByNearestNeighbor } from "./sort.js";
const asAxiDraw = defmulti(
  __dispatch,
  {
    arc: "circle",
    cubic: "circle",
    ellipse: "circle",
    line: "polyline",
    path: "circle",
    poly: "polyline",
    quad: "polyline",
    quadratic: "circle",
    rect: "polyline",
    tri: "polyline"
  },
  {
    points: ($, opts) => __points(applyTransforms($).points, $.attribs, opts),
    // used for all shapes which need to be sampled
    circle: ($, opts) => mapcat(
      (line) => __polyline(line.points, $.attribs, opts),
      asPolyline(applyTransforms($), opts?.samples)
    ),
    complexpoly: ($, opts) => mapcat(
      (poly) => asAxiDraw(withAttribs(poly, $.attribs, false), opts),
      [$.boundary, ...$.children]
    ),
    // ignore sample opts for polyline & other polygonal shapes
    // i.e. use points verbatim
    polyline: ($, opts) => __polyline(
      asPolyline(applyTransforms($))[0].points,
      $.attribs,
      opts
    ),
    group: __group
  }
);
function* __interleaved(emitChunk, items, opts) {
  const { num, commands } = opts;
  if (opts.start !== false) yield* commands(0);
  for (let i = 0, n = items.length; i < n; ) {
    yield* emitChunk(items.slice(i, i + num));
    i += num;
    if (i < n) yield* commands(i);
  }
  if (opts.end) yield* opts.commands(items.length);
}
function* __group($, opts) {
  const $sampleOpts = __sampleAttribs(opts?.samples, $.attribs);
  const { skip, sort, interleave } = __axiAttribs($.attribs);
  const children = skip ? [...takeNth(skip + 1, $.children)] : $.children;
  function* emitChunk(chunk) {
    const iter = sort ? sort(chunk) : chunk;
    for (const child of iter) {
      const shape = applyTransforms(child);
      shape.attribs = {
        ...$.attribs,
        ...shape.attribs,
        __samples: __sampleAttribs($sampleOpts, shape.attribs)
      };
      yield* asAxiDraw(shape, opts);
    }
  }
  yield* interleave ? __interleaved(emitChunk, children, interleave) : emitChunk(children);
}
function* __points(pts, attribs, opts) {
  if (!pts.length) return;
  const {
    sort = pointsByNearestNeighbor(),
    clip,
    delayDown,
    delayUp,
    down,
    interleave,
    skip,
    speed
  } = __axiAttribs(attribs);
  const clipPts = clip || opts?.clip;
  if (clipPts) {
    pts = pts.filter((p) => !!pointInPolygon2(p, clipPts));
    if (!pts.length) return;
  }
  if (skip) {
    pts = [...takeNth(skip + 1, pts)];
  }
  function* emitChunk($pts) {
    if (down != void 0) yield ["pen", down];
    for (const p of sort ? sort($pts) : $pts) {
      yield MOVE(p, speed);
      yield DOWN(delayDown);
      yield UP(delayUp);
    }
    if (down != void 0) yield ["pen"];
  }
  yield UP();
  yield* interleave ? __interleaved(emitChunk, pts, interleave) : emitChunk(pts);
}
function* __polyline(pts, attribs, opts) {
  if (!pts.length) return;
  const { clip, down, delayDown, delayUp, speed } = __axiAttribs(attribs);
  const clipPts = clip || opts?.clip;
  const chunks = clipPts ? clipPolylinePoly(pts, clipPts) : [pts];
  if (!chunks.length) return;
  for (const chunk of chunks) {
    yield* polyline(chunk, { down, delayDown, delayUp, speed });
  }
}
const __axiAttribs = (attribs) => attribs ? attribs.__axi || {} : {};
export {
  asAxiDraw
};