@thi.ng/webgl/shaders/lambert.js

WebGL & GLSL abstraction layer

import {
  diffuseLighting,
  halfLambert,
  lambert
} from "@thi.ng/shader-ast-stdlib/light/lambert";
import { transformMVP } from "@thi.ng/shader-ast-stdlib/matrix/mvp";
import { surfaceNormal } from "@thi.ng/shader-ast-stdlib/matrix/normal";
import { M4, S2D, V2, V3 } from "@thi.ng/shader-ast/api/types";
import { assign } from "@thi.ng/shader-ast/ast/assign";
import { defMain } from "@thi.ng/shader-ast/ast/function";
import { vec4 } from "@thi.ng/shader-ast/ast/lit";
import { mul } from "@thi.ng/shader-ast/ast/ops";
import { $ } from "@thi.ng/shader-ast/ast/swizzle";
import { normalize } from "@thi.ng/shader-ast/builtin/math";
import { texture } from "@thi.ng/shader-ast/builtin/texture";
import { defMaterial } from "../material.js";
import { autoNormalMatrix2 } from "../matrices.js";
import { colorAttrib, positionAttrib } from "../utils.js";
const LAMBERT = (opts = {}) => ({
  vs: (gl, unis, ins, outs) => [
    defMain(() => [
      opts.uv ? assign(outs.vuv, ins[opts.uv]) : null,
      assign(outs.vcolor, colorAttrib(opts, ins, unis.diffuseCol)),
      assign(outs.vnormal, surfaceNormal(ins.normal, unis.normalMat)),
      assign(
        gl.gl_Position,
        transformMVP(
          positionAttrib(opts, ins),
          unis.model,
          unis.view,
          unis.proj
        )
      )
    ])
  ],
  fs: (_, unis, ins, outs) => [
    defMain(() => [
      assign(
        outs.fragColor,
        vec4(
          diffuseLighting(
            (opts.bidir !== false ? halfLambert : lambert)(
              normalize(ins.vnormal),
              unis.lightDir
            ),
            opts.uv ? mul(
              $(texture(unis.tex, ins.vuv), "xyz"),
              ins.vcolor
            ) : ins.vcolor,
            unis.lightCol,
            unis.ambientCol
          ),
          1
        )
      )
    ])
  ],
  // pre: ALIAS_TEXTURE,
  attribs: {
    position: V3,
    normal: V3,
    ...opts.uv ? { [opts.uv]: V2 } : null,
    ...opts.color && !opts.instanceColor ? { [opts.color]: V3 } : null,
    ...opts.instancePos ? { [opts.instancePos]: V3 } : null,
    ...opts.instanceColor ? { [opts.instanceColor]: V3 } : null
  },
  varying: {
    vcolor: V3,
    vnormal: V3,
    ...opts.uv ? { vuv: V2 } : null
  },
  uniforms: {
    model: M4,
    view: M4,
    proj: M4,
    normalMat: [M4, autoNormalMatrix2()],
    lightDir: [V3, [0, 1, 0]],
    lightCol: [V3, [1, 1, 1]],
    ...defMaterial(
      { diffuseCol: [1, 1, 1], ...opts.material },
      { specularCol: false }
    ),
    ...opts.uv ? { tex: S2D } : null
  },
  state: {
    depth: true,
    cull: true,
    ...opts.state
  }
});
export {
  LAMBERT
};