// -- https://xemantic.github.io/shader-web-background/
const shaderWebBackground = {}; (() => {
  'use strict'; const t = (a, b) => {
    b.initHalfFloatRGBATexture(b.width, b.height); a.texParameteri(a.TEXTURE_2D,
      a.TEXTURE_MIN_FILTER, a.LINEAR); a.texParameteri(a.TEXTURE_2D, a.TEXTURE_MAG_FILTER,
        a.LINEAR); a.texParameteri(a.TEXTURE_2D, a.TEXTURE_WRAP_S, a.CLAMP_TO_EDGE); a.texParameteri(a.TEXTURE_2D,
          a.TEXTURE_WRAP_T, a.CLAMP_TO_EDGE)
  }, x = (a, b) => {
    console.warn("shader-web-background cannot shade, adding fallback CSS classes");
    document.documentElement.classList.add("shader-web-background-fallback"); b.classList.add("shader-web-background-fallback");
    if (a instanceof shaderWebBackground.GlError) console.warn("Not sufficient WebGL support:",
      a); else throw a;
  };
  function y(a, b) { if (!a) throw new shaderWebBackground.ConfigError(b); }
  function z(a) {
    y(a instanceof HTMLCanvasElement, "config.canvas must be instance of canvas");
    return a
  }
  function A() {
    const a = document.createElement("canvas"), b = a.style; a.id = "shader-web-background"; b.width =
      "100vw"; b.height = "100vh"; b.position = "fixed"; b.top = "0"; b.left = "0"; b.zIndex = -9999; return a
  }
  function B(a, b, c) {
    y(a instanceof HTMLScriptElement && a.type === b, 'Shader source element of id "' +
      c + '" should be of type: <script type="' + (b + '" id="' + c + '">'))
  }
  function D(a) {
    const b = document.getElementById(a); y(b, 'Missing shader source: <script type="x-shader/x-fragment" id="' +
      (a + '">')); B(b, "x-shader/x-fragment", a); return b.text
  }
  function E(a) {
    a += "Vertex"; const b = document.getElementById(a); return b ? (B(b, "x-shader/x-vertex",
      a), b.text) : "attribute vec2 V;void main(){gl_Position=vec4(V,0,1);}"
  }
  function F(a, b) { "loading" !== document.readyState ? b() : window.addEventListener(a, b) }
  class G {
    constructor(a, b, c, d) {
      this.g = c; const l = a.gl; this.h = () => {
        for (const f of d) f.u(l,
          f.location, b)
      }; this.i = () => {
        var f = c.v, h = a.gl; h.bindBuffer(h.ARRAY_BUFFER, a.j); h.enableVertexAttribArray(f);
        h.vertexAttribPointer(f, 2, h.FLOAT, !1, 0, 0); h.drawArrays(h.TRIANGLE_STRIP, 0, 4); h.disableVertexAttribArray(f);
        h.bindBuffer(h.ARRAY_BUFFER, null); f = a.gl; for (h = 0; h < a.g; h++)f.activeTexture(f.TEXTURE0 +
          h), f.bindTexture(f.TEXTURE_2D, null); a.g = 0
      }
    }
  }
  function H(a) {
    var b = { antialias: !1, depth: !1, alpha: !1 }; try { return new I(a, b) } catch (c) {
      throw new shaderWebBackground.GlError(c.message);
    }
  }
  function J(a, b, c, d, l, f) {
    function h(e, m, n) {
      try {
        {
          var k = p; const q = k.gl, P = K(k, e, q.VERTEX_SHADER, m),
            Q = K(k, e, q.FRAGMENT_SHADER, n), v = q.createProgram(); q.attachShader(v, P); q.attachShader(v,
              Q); q.linkProgram(v); var r = v
        } return r
      } catch (q) {
        throw new shaderWebBackground.ConfigError(q.message);
      }
    } const p = H(a), w = [], g = {
      gl: p.gl, canvas: a, width: 0, height: 0, cssPixelRatio: 0, cssWidth: 0,
      cssHeight: 0, isOverShader: (e, m) => {
        const n = a.getBoundingClientRect(); return e >= n.left &&
          e <= n.right && m >= n.top && m <= n.bottom
      }, toShaderX: e => (e - a.getBoundingClientRect().left) *
        g.cssPixelRatio + .5, toShaderY: e => a.height - (e - a.getBoundingClientRect().top) * g.cssPixelRatio -
          .5, s: () => g.cssWidth !== a.clientWidth || g.cssHeight !== a.clientHeight ? (g.resize(), !0) :
            !1, resize: () => {
              const e = window.devicePixelRatio || 1, m = a.clientWidth, n = a.clientHeight,
              k = Math.floor(m * e), r = Math.floor(n * e); a.width = k; a.height = r; g.width = k; g.height = r; g.cssPixelRatio =
                e; g.cssWidth = m; g.cssHeight = n; p.gl.viewport(0, 0, p.canvas.width, p.canvas.height); for (const q of w) q.g.l(k,
                  r)
            }, texture: (e, m) => {
              {
                var n = p; const k = n.gl; m = m instanceof L ? m.g : m; k.activeTexture(k.TEXTURE0 +
                  n.g); k.bindTexture(k.TEXTURE_2D, m); k.uniform1i(e, n.g++)
              }
            }, buffers: {}, initHalfFloatRGBATexture: (e,
              m) => { p.h.g(e, m) }
    }, R = Object.keys(b).length - 1; let S = 0; for (const e in b) {
      if (S++ < R) {
        const k =
          b[e].texture || t; g.buffers[e] = M(p, () => { k(p.gl, g) })
      } const m = N(p, h(e, E(e), D(e)), g.buffers[e]),
        n = b[e].uniforms || {}; var u = Object.keys(n); for (const k of m.m) y(n[k.name], 'No configuration for uniform "' +
          k.name + '" defined in shader "' + e + '"'), u = u.filter(r => r !== k.name); 0 !== u.length && console.warn('Extra uniforms configured for shader "' +
            e + '", which are not present in the shader code - might have been removed by GLSL compiler if not used: ' +
            u.join(", ")); u = m.m.map(k => ({ location: k.location, u: n[k.name] })); w.push(new G(p, g,
              m, u))
    } const C = () => {
      g.s() && d && d(g.width, g.height, g); l && l(g); for (const e of w) e.g.i(e.h,
        e.i); f && f(g); requestAnimationFrame(C)
    }; F("load", () => {
      g.resize(); c && c(g); d && d(g.width,
        g.height, g); requestAnimationFrame(C)
    }); return g
  }
  shaderWebBackground.Error = class extends Error { constructor(a) { super(a); this.name = "shaderWebBackground.Error" } };
  shaderWebBackground.ConfigError = class extends shaderWebBackground.Error {
    constructor(a) {
      super(a);
      this.name = "shaderWebBackground.ConfigError"
    }
  };
  shaderWebBackground.GlError = class extends shaderWebBackground.Error {
    constructor(a) {
      super(a); this.name =
        "shaderWebBackground.GlError"
    }
  };
  shaderWebBackground.shade = function(a) {
    y(a, "Missing config argument"); const b = a.canvas ?
      z(a.canvas) : A(); y(a.shaders, "No shaders specified in config"); try {
        const c = J(b, a.shaders,
          a.onInit, a.onResize, a.onBeforeFrame, a.onAfterFrame); a.canvas || F("DOMContentLoaded",
            () => { document.body.appendChild(b) }); return c
      } catch (c) { (a.onError || x)(c, b) }
  }; const O = [-1, 1, 1, 1, -1, -1, 1, -1];
  function T(a, b) { return a.j(a.gl.getExtension(b), b + " extension is not supported") }
  class U { constructor(a, b) { this.gl = a; this.j = b } g() { } }
  class V extends U {
    constructor(a, b) {
      super(a, b); this.h = T(this, "OES_texture_half_float");
      T(this, "OES_texture_half_float_linear")
    } g(a, b) {
      const c = this.gl; c.texImage2D(c.TEXTURE_2D,
        0, c.RGBA, a, b, 0, c.RGBA, this.h.HALF_FLOAT_OES, null)
    }
  }
  class W extends U {
    constructor(a, b) { super(a, b); T(this, "EXT_color_buffer_float"); this.gl.getExtension("OES_texture_float_linear") } g(a,
      b) {
        const c = this.gl; c.texImage2D(c.TEXTURE_2D, 0, c.RGBA16F, a, b, 0, c.RGBA, c.HALF_FLOAT,
          null)
    }
  }
  function X(a) {
    a = a.split(/\r?\n/); const b = a.length.toString().length; var c = []; a.forEach((d,
      l) => {
        l = (l + 1).toString(); l = l.length >= b ? l : " ".repeat(b - l.length) + l; c.push(l + ": " + d +
          "\n")
    }); return c.join("")
  } function M(a, b) { return new L(a.gl, () => { b(a.gl) }) }
  function N(a, b, c) {
    const d = a.gl; a = []; const l = d.getProgramParameter(b, d.ACTIVE_UNIFORMS);
    for (let f = 0; f < l; f++) {
      const h = d.getActiveUniform(b, f); a.push({
        name: h.name, location: d.getUniformLocation(b,
          h.name)
      })
    } return {
      v: d.getAttribLocation(b, "V"), m: a, l: c ? (f, h) => c.l(f, h) : () => { }, i: (f,
        h) => { d.useProgram(b); f(); c ? (f = c.g, c.g = c.h, c.h = f, c.i(h)) : h() }
    }
  }
  function K(a, b, c, d) {
    a = a.gl; c = a.createShader(c); a.shaderSource(c, d); a.compileShader(c);
    if (!a.getShaderParameter(c, a.COMPILE_STATUS)) {
      const l = String(a.getShaderInfoLog(c));
      a.deleteShader(c); b = "Cannot compile shader - " + b + ": " + l; console.log(b); console.log(X(d));
      throw Error(b);
    } return c
  }
  class I {
    constructor(a, b) {
      this.canvas = a; const c = (l, f) => { if (!l) throw Error(f); return l };
      let d = a.getContext("webgl2", b); if (d) this.h = new W(d, c); else if (d = a.getContext("webgl",
        b)) this.h = new V(d, c); c(d, "webgl context not supported on supplied canvas element: " +
          a); this.gl = d; a = d.createBuffer(); d.bindBuffer(d.ARRAY_BUFFER, a); d.bufferData(d.ARRAY_BUFFER,
            new Float32Array(O), d.STATIC_DRAW); d.bindBuffer(d.ARRAY_BUFFER, null); this.j = a; this.buffers =
              {}; this.g = 0
    }
  }
  function Y(a) {
    const b = a.gl, c = b.createTexture(); b.bindTexture(b.TEXTURE_2D, c); a.o(b);
    b.bindTexture(b.TEXTURE_2D, null); return c
  }
  class L {
    constructor(a, b) {
      this.j = a.createFramebuffer(); this.gl = a; this.o = b; this.g = this.h =
        null
    } l() {
      this.h && this.gl.deleteTexture(this.h); this.g && this.gl.deleteTexture(this.g);
      this.h = Y(this); this.g = Y(this)
    } i(a) {
      const b = this.gl; b.bindFramebuffer(b.FRAMEBUFFER,
        this.j); b.framebufferTexture2D(b.FRAMEBUFFER, b.COLOR_ATTACHMENT0, b.TEXTURE_2D, this.g,
          0); a(); b.framebufferTexture2D(b.FRAMEBUFFER, b.COLOR_ATTACHMENT0, b.TEXTURE_2D, null,
            0); b.bindFramebuffer(b.FRAMEBUFFER, null)
    }
  };
})()