@thi.ng/shader-ast-stdlib/tex/blur.js

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

import { S2D, V2, V4 } from "@thi.ng/shader-ast/api/types";
import { defn, ret } from "@thi.ng/shader-ast/ast/function";
import { vec2 } from "@thi.ng/shader-ast/ast/lit";
import { add, addSelf, div, mul, sub } from "@thi.ng/shader-ast/ast/ops";
import { sym } from "@thi.ng/shader-ast/ast/sym";
import { texture } from "@thi.ng/shader-ast/builtin/texture";
const __singlePass = (col, tex, uv, off, k) => addSelf(
  col,
  mul(add(texture(tex, add(uv, off)), texture(tex, sub(uv, off))), k)
);
const blur5 = defn(
  V4,
  "blur5",
  [S2D, V2, V2, V2],
  (tex, res, uv, dir) => {
    let col;
    let off;
    const k1 = 0.29411764705882354;
    const k2 = 0.35294117647058826;
    return [
      off = sym(div(mul(vec2(1 + 1 / 3), dir), res)),
      col = sym(mul(texture(tex, uv), k1)),
      __singlePass(col, tex, uv, off, k2),
      ret(col)
    ];
  }
);
const blur9 = defn(
  V4,
  "blur9",
  [S2D, V2, V2, V2],
  (tex, res, uv, dir) => {
    let col;
    let off;
    let off2;
    let delta;
    const k1 = 0.3162162162;
    const k2 = 0.0702702703;
    return [
      delta = sym(div(dir, res)),
      off = sym(mul(delta, 1.3846153846)),
      off2 = sym(mul(delta, 3.2307692308)),
      col = sym(mul(texture(tex, uv), 0.227027027)),
      __singlePass(col, tex, uv, off, k1),
      __singlePass(col, tex, uv, off2, k2),
      ret(col)
    ];
  }
);
const blur13 = defn(
  V4,
  "blur13",
  [S2D, V2, V2, V2],
  (tex, res, uv, dir) => {
    let col;
    let off;
    let off2;
    let off3;
    let delta;
    const k1 = 0.2969069646728344;
    const k2 = 0.09447039785044732;
    const k3 = 0.010381362401148057;
    return [
      delta = sym(div(dir, res)),
      off = sym(mul(delta, 1.411764705882353)),
      off2 = sym(mul(delta, 3.2941176470588234)),
      off3 = sym(mul(delta, 5.176470588235294)),
      col = sym(mul(texture(tex, uv), 0.1964825501511404)),
      __singlePass(col, tex, uv, off, k1),
      __singlePass(col, tex, uv, off2, k2),
      __singlePass(col, tex, uv, off3, k3),
      ret(col)
    ];
  }
);
export {
  blur13,
  blur5,
  blur9
};