pokemon-color-search/nearest.js

const stripForm = ["flabebe", "floette", "florges", "vivillon", "basculin", "furfrou", "magearna"];

const getSprite = pokemon => {
  pokemon = pokemon
    .replace("-alola", "-alolan")
    .replace("-galar", "-galarian")
    .replace("darmanitan-galarian", "darmanitan-galarian-standard");
  if (stripForm.find(s => pokemon.includes(s))) {
    pokemon = pokemon.replace(/-.*$/, "");
  }
  return `https://img.pokemondb.net/sprites/sword-shield/icon/${pokemon}.png`;
}

const titleCase = s => s.charAt(0).toUpperCase() + s.substr(1);

const vectorDot = (u, v) => u.map((x, i) => x * v[i]).reduce((x, y) => x + y);

const vectorMag = v => Math.sqrt(vectorDot(v, v));

const getContrastingTextColor = rgb => vectorDot(rgb, [0.3, 0.6, 0.1]) >= 128 ? "#222" : "#ddd"

const pokemonLookup = new Fuse(database, { keys: [ "name" ] });

// hex codes already include leading # in these functions
// rgb values are [0, 255] in these functions
const jab2hex = jab => d3.jab(...jab).formatHex();
const rgb2hex = rgb => d3.rgb(...rgb).formatHex();
const rgb2jab = rgb => {
  const { J, a, b } = d3.jab(d3.rgb(...rgb));
  return [ J, a, b ];
}
const hex2rgb = hex => {
  const { r, g, b } = d3.rgb(hex);
  return [ r, g, b ];
};

// scoring functions
const getNormedScorer = (c, qRGB, qJAB) => {
  const fRGB = c / vectorMag(qRGB);
  const fJAB = c / vectorMag(qJAB);
  return ({ yRGB, yJAB }) => ({
    scoreRGB: fRGB * vectorDot(qRGB, yRGB) / vectorMag(yRGB),
    scoreJAB: fJAB * vectorDot(qJAB, yJAB) / vectorMag(yJAB),
  });
};
const getUnnormedScorer = (c, qRGB, qJAB) => ({ yRGB, yJAB }) => ({
  scoreRGB: c * vectorDot(qRGB, yRGB),
  scoreJAB: c * vectorDot(qJAB, yJAB),
});

// create a tile of a given hex color
const createTile = hexColor => {
  const tile = document.createElement("div");
  tile.setAttribute("class", "color-tile");
  tile.setAttribute("style", `background-color: ${hexColor};`)
  tile.textContent = hexColor;
  return tile;      
}

const renderPokemon = (
  { name, scoreRGB = null, scoreJAB = null, yRGB, yJAB },
  { rgbClass = "", jabClass = "" } = {},
) => {
  const titleName = titleCase(name);
  const rgbHex = rgb2hex(yRGB);
  const jabHex = jab2hex(yJAB);
  const textHex = getContrastingTextColor(yRGB);
  const rgbVec = yRGB.map(c => c.toFixed()).join(", ")
  const jabVec = yJAB.map(c => c.toFixed(2)).join(", ")
  const scoreClass = scoreRGB === null || scoreJAB === null ? "hide" : "";
  
  const pkmn = document.createElement("div");
  pkmn.setAttribute("class", "pokemon_tile");
  pkmn.innerHTML = `
    <div class="pokemon_tile-image-wrapper">
      <img src="${getSprite(name)}" />
    </div>
    <div class="pokemon_tile-info_panel">
      <span class="pokemon_tile-pokemon_name">${titleName}</span>
      <div class="pokemon_tile-results">
        <div class="pokemon_tile-labels">
          <span class="${jabClass}">Jab: </span>
          <span class="${rgbClass}">RGB: </span>
        </div>
        <div class="pokemon_tile-score_column ${scoreClass}">
          <span class="pokemon_tile-no_flex ${jabClass}">
            ${scoreJAB?.toFixed(2)}
          </span>
          <span class="pokemon_tile-no_flex ${rgbClass}">
            ${scoreRGB?.toFixed(2)}
          </span>
        </div>
        <div class="pokemon_tile-hex_column">
          <div class="pokemon_tile-hex_color ${jabClass}" style="background-color: ${jabHex}; color: ${textHex}">
            ${jabHex}
          </div>
          <div class="pokemon_tile-hex_color ${rgbClass}" style="background-color: ${rgbHex}; color: ${textHex}">
            ${rgbHex}
          </div>
        </div>
        <div class="pokemon_tile-vector_column">
          <span class="pokemon_tile-no_flex ${rgbClass}">(${rgbVec})</span>
          <span class="pokemon_tile-no_flex ${jabClass}">(${jabVec})</span>
        </div>
      </div>
    </div>
  `;
  return pkmn;
}

let lastColorSearch = null;
let lastPkmnSearch = null;

const paramsChanged = (...args) => {
  const old = lastColorSearch;
  lastColorSearch = args;
  return old === null || old.filter((p, i) => p !== args[i]).length > 0
}

const renderVec = math => `\\vec{${math.charAt(0)}}${math.substr(1)}`;

const renderNorm = vec => `\\frac{${vec}}{\\left|\\left|${vec}\\right|\\right|}`;

const renderMath = (includeX, normQY, closeCoeff) => {
  const xTerm = includeX ? "X\\left(P\\right)" : "";
  const qyMod = normQY ? c => renderNorm(renderVec(c)) : renderVec;
  return TeXZilla.toMathML(`\\arg\\min_{P}\\left[${xTerm}-${closeCoeff}${qyMod("q")}\\cdot ${qyMod("Y\\left(P\\right)")}\\right]`);
}

const renderQVec = (q, id) => {
  document.getElementById(id).innerHTML = TeXZilla.toMathMLString(`\\vec{q}_{\\text{RGB}} = \\left(${q.join(", ")}\\right)`);
}

const changePageColors = color => {
  // calculate luminance to determine if text should be dark or light
  const textColor = getContrastingTextColor([color.r, color.g, color.b]);
  document.querySelector("body").setAttribute("style", `background: ${color.formatHex()}; color: ${textColor}`);
}

const readColor = rgb => {
  const { J, a, b } = d3.jab(rgb);
  return [[rgb.r, rgb.g, rgb.b], [J, a, b]];
}

const onUpdate = (event) => {
  if (event) {
    event.preventDefault();
  }
  
  // Configuration Loading
  const includeX = document.getElementById("include-x")?.checked ?? false;
  const normQY = document.getElementById("norm-q-y")?.checked ?? false;
  const closeCoeff = document.getElementById("close-coeff")?.value ?? 2;
  const useRGB = document.getElementById("color-space")?.textContent === "RGB";
  const numPoke = document.getElementById("num-poke")?.value ?? 20;
  const pokemonName = document.getElementById("pokemon-name")?.value?.toLowerCase() ?? "";
  const colorInput = "#" + (document.getElementById("color-input")?.value?.replace("#", "") ?? "FFFFFF");

  // Check if parameters have changed
  const newParams = paramsChanged(includeX, normQY, closeCoeff, useRGB, numPoke, colorInput);

  if (newParams) {
    // Update display values
    document.getElementById("close-coeff-display").innerHTML = closeCoeff;
    document.getElementById("num-poke-display").textContent = numPoke;
    const objFnElem = document.getElementById("obj-fn");
    objFnElem.innerHTML = "";
    objFnElem.appendChild(renderMath(includeX, normQY, closeCoeff));
  }

  // Only modified if current color is valid
  let totalScorer = info => info;

  // Lookup by color
  if (colorInput.length === 7) {
    // Convert input color
    const targetColor = d3.color(colorInput);
    const [ targetRGB, targetJAB ] = readColor(targetColor);

    // Update the color display
    changePageColors(targetColor);
    renderQVec(targetRGB.map(c => c.toFixed()), "q-vec-rgb");
    renderQVec(targetJAB.map(c => c.toFixed(2)), "q-vec-jab");

    // Determine metrics from configuration
    const xSelector = includeX ? ({ xRGB, xJAB }) => [ xRGB, xJAB ] : () => [ 0, 0 ];
    const yScorer = (normQY ? getNormedScorer : getUnnormedScorer)(closeCoeff, targetRGB, targetJAB);
    
    // Set the scoring function
    totalScorer = info => {
      const [ xRGB, xJAB ] = xSelector(info);
      const { scoreRGB, scoreJAB } = yScorer(info);
      return {
        ...info,
        scoreRGB: xRGB - scoreRGB,
        scoreJAB: xJAB - scoreJAB,
      }
    };

    // Rescore Pokemon and update lists if config has changed
    if (newParams) {
      const scored = database.map(info => totalScorer(info));
  
      const bestListRGB = document.getElementById("best-list-rgb");
      bestListRGB.innerHTML = '';
      scored
        .sort((a, b) => a.scoreRGB - b.scoreRGB)
        .slice(0, numPoke)
        .forEach(info => {
          const li = document.createElement("li");
          li.appendChild(renderPokemon(info, { jabClass: "hide" }))
          bestListRGB.appendChild(li);
        });
  
      const bestListJAB = document.getElementById("best-list-jab");
      bestListJAB.innerHTML = '';
      scored
        .sort((a, b) => a.scoreJAB - b.scoreJAB)
        .slice(0, numPoke)
        .forEach(info => {
          const li = document.createElement("li");
          li.appendChild(renderPokemon(info, { rgbClass: "hide" }))
          bestListJAB.appendChild(li);
        });
    }
  }

  // Lookup by name
  const searchList = document.getElementById("search-list");
  searchList.innerHTML = '';
  if (pokemonName.length > 0 && (lastPkmnSearch !== pokemonName || newParams)) {
    pokemonLookup
      .search(pokemonName, { limit: 10 })
      // If scoring is impossible, totalScorer will just be identity
      .map(({ item }) => totalScorer(item))
      .forEach(item => {
        const li = document.createElement("li");
        li.appendChild(renderPokemon(item))
        searchList.appendChild(li);
      });
  }
  lastPkmnSearch = pokemonName;
};

const onRandomColor = () => {
  document.getElementById("color-input").value = rgb2hex([Math.random(), Math.random(), Math.random()].map(c => c * 255));
  onUpdate();
};