Class callback_t

source/external/tinyobj/tiny_obj_loader.h:424–460

};

struct callback_t {
  // W is optional and set to 1 if there is no `w` item in `v` line
  void (*vertex_cb)(void *user_data, real_t x, real_t y, real_t z, real_t w);
  void (*vertex_color_cb)(void *user_data, real_t x, real_t y, real_t z,
                          real_t r, real_t g, real_t b, bool has_color);
  void (*normal_cb)(void *user_data, real_t x, real_t y, real_t z);

  // y and z are optional and set to 0 if there is no `y` and/or `z` item(s) in
  // `vt` line.
  void (*texcoord_cb)(void *user_data, real_t x, real_t y, real_t z);

  // called per 'f' line. num_indices is the number of face indices(e.g. 3 for
  // triangle, 4 for quad)
  // 0 will be passed for undefined index in index_t members.
  void (*index_cb)(void *user_data, index_t *indices, int num_indices);
  // `name` material name, `material_id` = the array index of material_t[]. -1
  // if
  // a material not found in .mtl
  void (*usemtl_cb)(void *user_data, const char *name, int material_id);
  // `materials` = parsed material data.
  void (*mtllib_cb)(void *user_data, const material_t *materials,
                    int num_materials);
  // There may be multiple group names
  void (*group_cb)(void *user_data, const char **names, int num_names);
  void (*object_cb)(void *user_data, const char *name);

  callback_t()
      : vertex_cb(NULL),
        vertex_color_cb(NULL),
        normal_cb(NULL),
        texcoord_cb(NULL),
        index_cb(NULL),
        usemtl_cb(NULL),
        mtllib_cb(NULL),
        group_cb(NULL),
        object_cb(NULL) {}
};

class MaterialReader {
 public: