text: #define R_NO_REMAP
  #include <Rinternals.h>
  
  #include <freetypeharfbuzz.h>
  
  
  int (*fthb_get_font_info)(const char*, double, struct fthb_font_info*) = NULL;
  int (*fthb_calc_string_info)(const char*, const char*, double, struct fthb_string_info*) = NULL;
  int (*fthb_calc_string_width)(const char*, const char*, double, double*) = NULL;
  
  void fthb_init() {
    fthb_get_font_info =
      (int (*)(const char*, double, struct fthb_font_info*))
      R_GetCCallable("freetypeharfbuzz", "fthb_get_font_info");
  
    fthb_calc_string_info =
      (int (*)(const char*, const char*, double, struct fthb_string_info*))
      R_GetCCallable("freetypeharfbuzz", "fthb_calc_string_info");
  
    fthb_calc_string_width =
      (int (*)(const char*, const char*, double, double*))
      R_GetCCallable("freetypeharfbuzz", "fthb_calc_string_width");
  }
  