message: cleanup DifferentialGeometry.ih
  [ci skip]
diff: @@ -26,33 +26,32 @@ typedef enum
  {
  DG_FACEFORWARD = (1 << 0), /*!< face-forward normals */
  DG_NORMALIZE = (1 << 1), /*!< normalize normals */
  -// DG_WORLD_SPACE = (1<<2) obsolete: is always done
  - DG_NG = (1<<3), /*!< need geometry normal Ng */
  - DG_NS = (1<<4), /*!< need shading normal Ns */
  -// DG_MATERIAL = (1<<5), /*!< need material pointer; deprecated: is always done*/
  -// DG_GEOMETRY = (1<<6), /*!< need geometry pointer; deprecated: is always done*/
  - DG_MATERIALID = (1<<7), /*!< hack for now - return materialID as
  - stored in "prim.materialID" array */
  - DG_COLOR = (1<<8), /*!< hack for now - need interpolated vertex color */
  - DG_TEXCOORD = (1<<9), /*!< calculate texture coords st */
  - DG_TANGENTS = (1<<10),/*!< calculate tangents, i.e. the partial
  + DG_NG = (1 << 2), /*!< need geometry normal Ng */
  + DG_NS = (1 << 3), /*!< need shading normal Ns */
  + DG_MATERIALID = (1 << 4), /*!< return materialID if
  + "prim.materialID" array present*/
  + DG_COLOR = (1 << 5), /*!< hack for now - need interpolated vertex color */
  + DG_TEXCOORD = (1 << 6), /*!< calculate texture coords st */
  + DG_TANGENTS = (1 << 7), /*!< calculate tangents, i.e. the partial
  derivatives of position wrt. texture coordinates */
  } DG_PostIntersectFlags;
  -
  /*! differential geometry information that gives more detailed
  information on the actual geometry that a ray has hit */
  struct DifferentialGeometry
  {
  - vec3f P; //!< location of the hit-point, includes epsilon offset towards front side
  + vec3f P; //!< location of the hit-point, includes epsilon offset towards
  + //!< front side
  vec3f Ng; /*!< geometry normal if DG_NG was set, possibly not
  normalized/facefordwarded if DG_NORMALIZE and/or
  DG_FACEFORWARD weren't specified */
  vec3f Ns; /*!< shading normal if DG_NS was set, possibly not
  normalized/facefordwarded if DG_NORMALIZE and/or
  DG_FACEFORWARD weren't specified */
  - vec3f dPds; //!< tangent, the partial derivative of the hit-point wrt. texcoord s
  - vec3f dPdt; //!< bi-tangent, the partial derivative of the hit-point wrt. texcoord t
  + vec3f dPds; //!< tangent, the partial derivative of the hit-point wrt.
  + //!< texcoord s
  + vec3f dPdt; //!< bi-tangent, the partial derivative of the hit-point wrt.
  + //!< texcoord t
  vec2f st; //!< texture coordinates if DG_TEXCOORD was set
  vec4f color; /*! interpolated vertex color (rgba) if DG_COLOR was set;
  defaults to vec4f(1.f) if queried but not present in geometry
  