@thi.ng/pixel/format/float-format.js

Typedarray integer & float pixel buffers w/ customizable formats, blitting, drawing, convolution

import { identity } from "@thi.ng/api/fn";
import { clamp01 } from "@thi.ng/math/interval";
import { Lane } from "../api.js";
import { __luminanceABGR } from "../internal/utils.js";
const defFloatFormat = (fmt) => {
  const chan = fmt.channels;
  const chanShift = chan.reduce(
    (acc, ch) => (acc[ch] = 3 - ch << 3, acc),
    {}
  );
  const res = {
    ...fmt,
    __float: true,
    size: chan.length,
    shift: chanShift,
    range: [0, 1],
    normalized: clamp01,
    fromNormalized: identity
  };
  if (fmt.convert) {
    Object.assign(res, fmt.convert);
    return res;
  }
  const to = (col, i) => (clamp01(col[i]) * 255 + 0.5 | 0) << chanShift[chan[i]];
  const from = (col, i) => (col >>> chanShift[chan[i]] & 255) / 255;
  switch (chan.length) {
    case 1:
      fmt.gray ? __defConvert1Gray(res) : __defConvert1(res, from, to);
      break;
    case 2:
      fmt.gray ? __defConvert2Gray(res, from) : __defConvert2(res, from, to);
      break;
    case 3:
      __defConvert3(res, from, to);
      break;
    case 4:
      __defConvert4(res, from, to);
      break;
  }
  return res;
};
const __defConvert1 = (res, from, to) => {
  res.toABGR = (col) => {
    let out = res.alpha ? 0 : 4278190080;
    out |= to(col, 0);
    return out >>> 0;
  };
  res.fromABGR = (col, out = []) => {
    out[0] = from(col, 0);
    return out;
  };
};
const __defConvert1Gray = (res) => {
  res.toABGR = (col) => ((clamp01(col[0]) * 255 + 0.5 | 0) * 65793 | 4278190080) >>> 0;
  res.fromABGR = (col, out = []) => (out[0] = __luminanceABGR(col) / 255, out);
};
const __defConvert2 = (res, from, to) => {
  res.toABGR = (col) => {
    let out = res.alpha ? 0 : 4278190080;
    out |= to(col, 0);
    out |= to(col, 1);
    return out >>> 0;
  };
  res.fromABGR = (col, out = []) => {
    out[0] = from(col, 0);
    out[1] = from(col, 1);
    return out;
  };
};
const __defConvert2Gray = (res, from) => {
  const gray = ~~(res.channels[0] === Lane.ALPHA);
  const alpha = gray ^ 1;
  res.toABGR = (col) => {
    let out = (clamp01(col[gray]) * 255 + 0.5 | 0) * 65793;
    out |= (col[alpha] * 255 + 0.5 | 0) << 24;
    return out >>> 0;
  };
  res.fromABGR = (col, out = []) => {
    out[gray] = __luminanceABGR(col) / 255;
    out[alpha] = from(col, alpha);
    return out;
  };
};
const __defConvert3 = (res, from, to) => {
  res.toABGR = (col) => {
    let out = res.alpha ? 0 : 4278190080;
    out |= to(col, 0);
    out |= to(col, 1);
    out |= to(col, 2);
    return out >>> 0;
  };
  res.fromABGR = (col, out = []) => {
    out[0] = from(col, 0);
    out[1] = from(col, 1);
    out[2] = from(col, 2);
    return out;
  };
};
const __defConvert4 = (res, from, to) => {
  res.toABGR = (col) => {
    let out = res.alpha ? 0 : 4278190080;
    out |= to(col, 0);
    out |= to(col, 1);
    out |= to(col, 2);
    out |= to(col, 3);
    return out >>> 0;
  };
  res.fromABGR = (col, out = []) => {
    out[0] = from(col, 0);
    out[1] = from(col, 1);
    out[2] = from(col, 2);
    out[3] = from(col, 3);
    return out;
  };
};
export {
  defFloatFormat
};