@thi.ng/shader-ast-stdlib/noise/curl3.js

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

import { F, V3 } from "@thi.ng/shader-ast/api/types";
import { defn, ret } from "@thi.ng/shader-ast/ast/function";
import { vec2, vec3 } from "@thi.ng/shader-ast/ast/lit";
import { add, div, mul, sub } from "@thi.ng/shader-ast/ast/ops";
import { $, $x, $y, $z } from "@thi.ng/shader-ast/ast/swizzle";
import { sym } from "@thi.ng/shader-ast/ast/sym";
import { snoiseVec3 } from "./simplex3.js";
const curlNoise3 = defn(V3, "curlNoise3", [V3, F], (p, e) => {
  let D;
  let px0;
  let px1;
  let py0;
  let py1;
  let pz0;
  let pz1;
  return [
    D = sym(vec2(e, 0)),
    px0 = sym(snoiseVec3(sub(p, $(D, "xyy")))),
    px1 = sym(snoiseVec3(add(p, $(D, "xyy")))),
    py0 = sym(snoiseVec3(sub(p, $(D, "yxy")))),
    py1 = sym(snoiseVec3(add(p, $(D, "yxy")))),
    pz0 = sym(snoiseVec3(sub(p, $(D, "yyx")))),
    pz1 = sym(snoiseVec3(add(p, $(D, "yyx")))),
    ret(
      div(
        vec3(
          add(sub(sub($z(py1), $z(py0)), $y(pz1)), $y(pz0)),
          add(sub(sub($x(pz1), $x(pz0)), $z(px1)), $z(px0)),
          add(sub(sub($y(px1), $y(px0)), $x(py1)), $x(py0))
        ),
        mul(2, e)
      )
    )
  ];
});
export {
  curlNoise3
};