Your program must make a successful call to initgraph before calling
getgraphmode.
The enumeration graphics_mode, defined in graphics.h, gives names for the
predefined graphics modes. For a table listing these enumeration values,
refer to the description for initgraph.
/* getgraphmode 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, mode;
char numname[80], modename[80];
/* 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;
/* get mode number and name strings */
mode = getgraphmode();
sprintf(numname, "%d is the current mode number.", mode);
sprintf(modename, "%s is the current graphics mode.", getmodename
(mode));
/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, numname);
outtextxy(midx, midy+2*textheight("W"), modename);
/* clean up */
getch();
closegraph();
return 0;
}