#include <graphics.h>
int registerbgifont(void (*font)(void));
 

Calling registerbgifont informs the graphics system that the font pointed
to by font was included at link time. This routine checks the linked-in
code for the specified font; if the code is valid, it registers the code
in internal tables.
By using the name of a linked-in font in a call to registerbgifont, you
also tell the compiler (and linker) to link in the object file with that
public name.
If you register a user-supplied font, you must pass the result of
registerbgifont to settextstyle as the font number to be used.

/* registerbgifont example */
 
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
 
int main(void)
{
   /* request autodetection */
   int gdriver = DETECT, gmode, errorcode;
   int midx, midy;
 
   /* register a font file that was added into GRAPHICS.LIB */
   errorcode = registerbgifont(triplex_font);
 
   /* report any registration errors */
   if (errorcode < 0) {
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
 
getch();
exit(1);   /* terminate with an error code */
   }
 
   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, "");
 
   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk) {  /* an error occurred */
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1);   /* terminate with an error code */
 
   }
 
   midx = getmaxx() / 2;
   midy = getmaxy() / 2;
 
   /* select the registered font */
   settextstyle(TRIPLEX_FONT, HORIZ_DIR, 4);
 
   /* output some text */
   settextjustify(CENTER_TEXT, CENTER_TEXT);
   outtextxy(midx, midy, "The TRIPLEX FONT");
 
   /* clean up */
   getch();
   closegraph();
   return 0;
}

graphresult initgraph installuserdriver registerbgidriver settextstyle

  no output of example at the moment
  do not hesitate and add it...