@thi.ng/shader-ast-stdlib/math/pack-float.js

Function collection for modular GPGPU / shader programming with @thi.ng/shader-ast

import { F, V4 } from "@thi.ng/shader-ast/api/types";
import { defn, ret } from "@thi.ng/shader-ast/ast/function";
import { vec4 } from "@thi.ng/shader-ast/ast/lit";
import { mul, sub } from "@thi.ng/shader-ast/ast/ops";
import { $ } from "@thi.ng/shader-ast/ast/swizzle";
import { sym } from "@thi.ng/shader-ast/ast/sym";
import { dot, fract } from "@thi.ng/shader-ast/builtin/math";
const packFloat = defn(V4, null, [F], (x) => {
  let res;
  return [
    res = sym(fract(mul(vec4(1, 255, 65025, 16581375), x))),
    ret(sub(res, mul($(res, "yzww"), vec4(1 / 255, 1 / 255, 1 / 255, 0))))
  ];
});
const unpackFloat = defn(F, null, [V4], (v) => [
  ret(dot(v, vec4(1, 1 / 255, 1 / 65025, 1 / 16581375)))
]);
export {
  packFloat,
  unpackFloat
};