@sutton-signwriting/font-db/swu/swu-sign-normalize.js

a javascript package for node that generates SVG and PNG images for individual symbols and complete signs

const { db } = require('../db/db');
const { swu, convert } = require('@sutton-signwriting/core');

/**
 * Function that normalizes an SWU sign for a center of 500,500
 * @function swu.signNormalize
 * @param {string} swuSign - an SWU sign with optional style string
 * @returns {string} normalized sign
 * @example
 * // using promise.then
 * swu.signNormalize('𝠃𝤟𝤩񋛩𝣵𝤐񀀒𝤇𝣤񋚥𝤐𝤆񀀚𝣮𝣭').then( norm => {
 *   console.log(norm)
 * })
 * @example
 * // using async/await
 * const norm = await swu.signNormalize('𝠃𝤟𝤩񋛩𝣵𝤐񀀒𝤇𝣤񋚥𝤐𝤆񀀚𝣮𝣭')
 */
const signNormalize = async (swuSign) => {
  const blank = '';
  const parsed = swu.parse.sign(swuSign);
  if (!parsed.spatials) return blank;

  const symbols = parsed.spatials.map((spatial) => spatial.symbol);
  const syms = await db.query(`select id, width, height from symbol where id in (${symbols.map(s => convert.swu2id(s)).join(',')})`);
  if (!syms.length) return blank;
  const symbolsizes = syms.reduce((obj, row) => {
    obj[convert.id2swu(row.id)] = row
    return obj;
  }, {})
  const bbox = (symbols) => {
    const x1 = Math.min(...symbols.map(spatial => spatial.coord[0]));
    const y1 = Math.min(...symbols.map(spatial => spatial.coord[1]));
    const x2 = Math.max(...symbols.map(spatial => spatial.coord[0] + parseInt(symbolsizes[spatial.symbol].width)));
    const y2 = Math.max(...symbols.map(spatial => spatial.coord[1] + parseInt(symbolsizes[spatial.symbol].height)));
    return {
      x1: x1,
      y1: y1,
      x2: x2,
      y2: y2
    };
  }

  const hrange = swu.ranges['hcenter'];
  const hsyms = parsed.spatials.filter((spatial) => {
    const dec = parseInt(spatial.symbol.slice(1, 4), 16);
    return (hrange[0] <= dec && hrange[1] >= dec);
  })

  const vrange = swu.ranges['vcenter'];
  const vsyms = parsed.spatials.filter((spatial) => {
    const dec = parseInt(spatial.symbol.slice(1, 4), 16);
    return (vrange[0] <= dec && vrange[1] >= dec);
  })

  let abox = bbox(parsed.spatials);
  let max = [abox.x2, abox.y2];
  if (hsyms.length) {
    const hbox = bbox(hsyms);
    abox.x1 = hbox.x1;
    abox.x2 = hbox.x2;
  }
  if (vsyms.length) {
    const vbox = bbox(vsyms);
    abox.y1 = vbox.y1;
    abox.y2 = vbox.y2;
  }

  const offset = [parseInt((abox.x2 + abox.x1) / 2) - 500, parseInt((abox.y2 + abox.y1) / 2) - 500]
  return (parsed.sequence ? '𝠀' + parsed.sequence.join('') : '') +
    parsed.box + convert.coord2swu([max[0] - offset[0], max[1] - offset[1]]) +
    parsed.spatials.map(spatial => spatial.symbol + convert.coord2swu([spatial.coord[0] - offset[0], spatial.coord[1] - offset[1]])).join('') +
    (parsed.style || '');
}

if (require.main === module) {
  signNormalize(process.argv[2]).then( res => {
    console.log(res);
  })
} else {
  module.exports = { signNormalize }
}