PRODUCT  :  Borland C++                            NUMBER  :  707
  VERSION  :  2.0
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  1/3

    TITLE  :  Linking Third Party BGI Drivers




  /*************************************************************
  This document explains how to link third party graphics drivers
  into your program.  This example is specific to the vga256.bgi
  driver which is available on the Borland BBS (408) 431-5096.  The
  procedure is the same to link in one of the drivers that was
  shipped with your product except that  you don't need to make the
  call to installuserdriver() function which means that you also
  don't need the alwayszero() function.

     1.  Convert vga256.bgi to an object file with this command:

         BGIOBJ vga256.bgi vga256.obj _vga256_driver

     2.  Create a project file for the program that links in the
         driver.  The project should contain two items:

                 A.  test.c
                 B.  vga256.obj

     3.  Here's what test.c would look like:

  ************************************************************/

  #include <graphics.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <conio.h>

  /* function prototypes */
  int huge alwayszero(void);
  void checkerrors(void);
  void  _Cdecl vga256_driver(void);


  int main(void)
  {
     int gdriver, gmode;

     /* install the user defined driver into the system */
     gdriver = installuserdriver("vga256", alwayszero);

     /* check for any installation errors */
     checkerrors();













  PRODUCT  :  Borland C++                            NUMBER  :  707
  VERSION  :  2.0
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  2/3

    TITLE  :  Linking Third Party BGI Drivers




     /* register the driver with the graphics system */
     registerbgidriver(vga256_driver);

     /* check for any installation errors */
     checkerrors();

     /* initialize graphics and local variables */
     initgraph(&gdriver, &gmode, "");

     /* check for any initialization errors */
     checkerrors();

     /* draw a line */
     setcolor(WHITE);
     line(0, 0, getmaxx(), getmaxy());

     /* clean up */
     getch();
     closegraph();
     return 0;
  }

  int huge alwayszero(void)
  {
        return 0;
  }

  /* check for and report any graphics errors */
  void checkerrors(void)
  {
     int errorcode;

     /* read result of last graphics operation */
     errorcode = graphresult();
     if (errorcode != grOk)
     {
        printf("Graphics error: %s\n", grapherrormsg(errorcode));
        printf("Press any key to halt:");
        getch();
        exit(1);
     }
  }














  PRODUCT  :  Borland C++                            NUMBER  :  707
  VERSION  :  2.0
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  3/3

    TITLE  :  Linking Third Party BGI Drivers




  DISCLAIMER: You have the right to use this technical information
  subject to the terms of the No-Nonsense License Statement that
  you received with the Borland product to which this information
  pertains.