fitIntoBounds3

fitIntoBounds3.ts

// 3d version of the 2d fitIntoBounds2
// https://github.com/thi-ng/umbrella/blob/feaf8d3f8c1dd3e9141a151b4e473423a6f62242/packages/geom/src/ops/fit-into-bounds.ts#L34


import { Vec, MAX3, MIN3, ReadonlyVec, neg, div4, div3, abs3, sub3, dist3 } from '@thi.ng/vectors';
import { concat, translation44, ReadonlyMat, scale44, mulV344 } from '@thi.ng/matrices';
import { bounds, centroid } from '@thi.ng/geom-poly-utils';
import { isArray, isNull } from '@thi.ng/checks';

/**
 * Transform an array of 3d points by a 4x4 matrix.
 *
 * @param out
 * @param pts
 * @param mat
 * @returns out
 */
function transformV344(out: Vec[], pts: ReadonlyVec[], mat: ReadonlyMat) {
  if (isNull(out)) {
    out = pts;
  }

  if (isArray(out) && out.length === 0) {
    out = pts.map(_ => [0, 0, 0]);
  }

  if (!isArray(out)) {
    throw new Error('transform3 out must me an array or null');
  }

  if (isArray(out) && out.length !== pts.length) {
    throw new Error(`transform3: out must be an array with the the same length of input array`);
  }

  pts.forEach((point, i) => mulV344(out[i], mat, point));
  return out;
}

const translateScale3 = (
  out: Vec[],
  pts: Vec[],
  c1: ReadonlyVec,
  c2: ReadonlyVec,
  scaleMat: ReadonlyMat,
) =>
  /* prettier-ignore */
  transformV344(
    out,
    pts,
    concat(
      translation44([], c1),
      scaleMat,
      translation44([], c2)
    )
  );

/**
 * Fit a 3d point array into a 3d bounding box.
 *
 * @example
 * ```
 * const positions = [ [-1, 1, 1], [1, 1, 1] ]
 * fitIntoBounds3(null, positions, [
 *   [-8, -8, -8],
 *   [8, 8, 8],
 * ]);
 * ```
 *
 * @param out
 * @param pts
 * @param dest
 */
const fitIntoBounds3 = (out: Vec[], pts: Vec[], dest: Vec[]) => {
  const src = bounds(pts, [...MAX3], [...MIN3]);
  if (!src) return;

  const c = centroid(src);
  if (!c) return;

  /* prettier-ignore */
  const destSize = abs3(
    [], 
    [
      dest[0][0] - dest[1][0],
      dest[0][1] - dest[1][1],
      dest[0][2] - dest[1][2],
    ])

  /* prettier-ignore */
  const srcSize = abs3(
    [], 
    [
      src[0][0] - src[1][0],
      src[0][1] - src[1][1],
      src[0][2] - src[1][2],
    ])

  const tscale = div3([], destSize, srcSize);
  return translateScale3(out, pts, centroid(dest)!, neg(null, c), scale44([], tscale));
};

/*
######## ########  ######  ########
   ##    ##       ##    ##    ##
   ##    ##       ##          ##
   ##    ######    ######     ##
   ##    ##             ##    ##
   ##    ##       ##    ##    ##
   ##    ########  ######     ##
*/

const positions = [
  [-1, 1, 1],
  [1, 1, 1],
  /* NOTE: with a translation should works the same */
  // [4 + -1, 4 + 1, 4 + 1],
  // [4 + 1, 4 + 1, 4 + 1],
];
const positionsFit = fitIntoBounds3([], positions, [
  [-8, -8, -8],
  [8, 8, 8],
]);
/* NOTE: should be [-8, 8, 8], [8, 8, 8] */

console.log({ positionsFit });

/* NOTE: works perfectly */
const icosahedron = [
  [0, 0, 1.176],
  [1.051, 0, 0.526],
  [0.324, 1, 0.525],
  [-0.851, 0.618, 0.526],
  [-0.851, -0.618, 0.526],
  [0.325, -1, 0.526],
  [0.851, 0.618, -0.526],
  [0.851, -0.618, -0.526],
  [-0.325, 1, -0.526],
  [-1.051, 0, -0.526],
  [-0.325, -1, -0.526],
  [0, 0, -1.176],
]
const icosahedronFit = fitIntoBounds3([], icosahedron, [
  [-8, -8, -8],
  [8, 8, 8],
]);
const icosahedronFitBounds = bounds(icosahedronFit, [...MAX3], [...MIN3])
console.log({icosahedronFit, icosahedronFitBounds})