@thi.ng/shader-ast-stdlib/sdf/cross.js

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

import { F, V2 } from "@thi.ng/shader-ast/api/types";
import { assign } from "@thi.ng/shader-ast/ast/assign";
import { ifThen, ternary } from "@thi.ng/shader-ast/ast/controlflow";
import { defn, ret } from "@thi.ng/shader-ast/ast/function";
import { FLOAT0, FLOAT05, VEC2_0, vec2 } from "@thi.ng/shader-ast/ast/lit";
import { add, gt, madd, mul, neg, sub } from "@thi.ng/shader-ast/ast/ops";
import { $, $x, $y } from "@thi.ng/shader-ast/ast/swizzle";
import { sym } from "@thi.ng/shader-ast/ast/sym";
import { abs, length, max, min, sign } from "@thi.ng/shader-ast/builtin/math";
import { maxComp2 } from "../math/maxcomp.js";
const sdfCross2 = defn(F, "sdfCross2", [V2, V2, F], (p, size, r) => {
  let a, q, w;
  let k;
  return [
    a = sym(abs(p)),
    ifThen(gt($y(a), $x(a)), [assign(a, $(a, "yx"))]),
    q = sym(sub(a, size)),
    k = sym(maxComp2(q)),
    w = sym(
      ternary(gt(k, FLOAT0), q, vec2(sub($y(size), $x(a)), neg(k)))
    ),
    ret(madd(sign(k), length(max(w, VEC2_0)), r))
  ];
});
const sdfRoundedX2 = defn(F, "sdfRoundedX", [V2, F, F], (p, size, r) => {
  let q;
  return [
    q = sym(abs(p)),
    ret(sub(length(sub(q, mul(min(add($x(q), $y(q)), size), FLOAT05))), r))
  ];
});
export {
  sdfCross2,
  sdfRoundedX2
};