@thi.ng/shader-ast-stdlib/raymarch/direction.js

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

import { F, V2, V3 } from "@thi.ng/shader-ast/api/types";
import { defn, ret } from "@thi.ng/shader-ast/ast/function";
import { FLOAT2, vec3 } from "@thi.ng/shader-ast/ast/lit";
import { div, neg, sub } from "@thi.ng/shader-ast/ast/ops";
import { $y } from "@thi.ng/shader-ast/ast/swizzle";
import { sym } from "@thi.ng/shader-ast/ast/sym";
import { normalize, radians, tan } from "@thi.ng/shader-ast/builtin/math";
const raymarchDir = defn(
  V3,
  "raymarchDir",
  [V2, V2, F],
  (frag, res, fov) => {
    let uv;
    return [
      uv = sym(sub(frag, div(res, FLOAT2))),
      ret(
        normalize(
          vec3(uv, neg(div($y(res), tan(div(radians(fov), FLOAT2)))))
        )
      )
    ];
  }
);
export {
  raymarchDir
};