struct LightingResult
{
  // material-dependent lighting data
  vec3 diffuseColorWithLighting, specularColorWithLighting;

  // pure lighting
  vec3 directDiffuse, directSpecular, directGF;
  vec3 environmentDiffuse, environmentSpecular, environmentGF;
  float shadow, ao;
  vec3 lightmapColor;
  vec3 emissive;

  // advanced
  vec3 fresnel; // for transmit materials , rim or special effects

#if CC_SURFACES_LIGHTING_USE_MULTIPLE_LAYER_BLEND
  vec3 directDiffuseSubLayers, directSpecularSubLayers;
  vec3 environmentDiffuseSubLayers, environmentSpecularSubLayers;
#endif

#if CC_SURFACES_LIGHTING_TRANSMIT_SPECULAR
  vec3 directTransmitSpecular, environmentTransmitSpecular;
#endif
#if CC_SURFACES_LIGHTING_TRANSMIT_DIFFUSE
  vec3 directTransmitDiffuse, environmentTransmitDiffuse;
#endif
  // used for retro/internal-reflection such as TRT, Dual-Lobe Specular, Sheen...
  // multi-layer (coat) just temporary use here, it should be moved to LightingResultPerLayer member
#if CC_SURFACES_LIGHTING_2ND_LAYER_SPECULAR
  vec3 direct2ndSpecular, environment2ndSpecular;
  vec3 specularColorWithLighting2ndSpecular;
  vec3 directGF2ndSpecular, environmentGF2ndSpecular;
  vec3 directSubLayerF, environmentSubLayerF;
#endif
#if CC_SURFACES_LIGHTING_TT
  vec3 directTT;
  vec3 diffuseColorWithLightingTT;
#endif
  //vec3 scattered;
};


/* for multi-layer materials, should define:
struct LightingResultPerLayer
{
  vec3 diffuseColorWithLighting, specularColorWithLighting;
  vec3 directDiffuse, directSpecular, directGF;
  vec3 environmentDiffuse, environmentSpecular, environmentGF;
  vec3 directSubLayerF, environmentSubLayerF;
}*/