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

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

import { assert } from "@thi.ng/errors/assert";
import { clamp01 } from "@thi.ng/math/interval";
import { __compileFromABGR, __compileToABGR } from "../internal/codegen.js";
const __defChannel = (ch, idx, shift) => {
  const num = 1 << ch.size;
  const mask0 = num - 1;
  const maskA = mask0 << shift >>> 0;
  const invMask = ~maskA >>> 0;
  const lane = ch.lane != null ? ch.lane : idx;
  const int = (x) => x >>> shift & mask0;
  const setInt = (src, x) => src & invMask | (x & mask0) << shift;
  return {
    size: ch.size,
    num,
    abgrShift: 24 - lane * 8 - shift,
    lane,
    shift,
    mask0,
    maskA,
    int,
    setInt,
    float: (x) => int(x) / mask0,
    setFloat: (src, x) => setInt(src, clamp01(x) * mask0)
  };
};
const defIntFormat = (fmt) => {
  assert(fmt.channels.length > 0, "no channel specs given");
  const channels = fmt.channels.reduce(
    ([defs, shift], ch, i) => {
      shift -= ch.size;
      defs.push(__defChannel(ch, i, shift));
      return [defs, shift];
    },
    [[], fmt.size]
  )[0];
  return {
    __packed: true,
    type: fmt.type,
    size: fmt.size,
    alpha: fmt.alpha || 0,
    channels,
    fromABGR: fmt.fromABGR || __compileFromABGR(channels),
    toABGR: fmt.toABGR || __compileToABGR(channels, !!fmt.alpha)
  };
};
export {
  defIntFormat
};