import * as THREE from 'three';

export class SimulatorDepthMaterial extends THREE.MeshBasicMaterial {
  override onBeforeCompile(shader: {
    vertexShader: string;
    fragmentShader: string;
    uniforms: object;
  }) {
    shader.vertexShader = shader.vertexShader
      .replace(
        '#include <clipping_planes_pars_vertex>',
        [
          '#include <clipping_planes_pars_vertex>',
          'varying vec4 vViewCoordinates;',
        ].join('\n')
      )
      .replace(
        '#include <project_vertex>',
        ['#include <project_vertex>', 'vViewCoordinates = mvPosition;'].join(
          '\n'
        )
      );
    shader.fragmentShader = shader.fragmentShader
      .replace(
        '#include <clipping_planes_pars_fragment>',
        [
          '#include <clipping_planes_pars_fragment>',
          'varying vec4 vViewCoordinates;',
        ].join('\n')
      )
      .replace(
        '#include <dithering_fragment>',
        [
          '#include <dithering_fragment>',
          'gl_FragColor = vec4(-vViewCoordinates.z, 0.0, 0.0, 1.0);',
        ].join('\n')
      );
  }
}