getmaxx returns the maximum (screen-relative) x value for the current
graphics driver and mode.
For example, on a CGA in 320*200 mode, getmaxx returns 319. getmaxx is
invaluable for centering, determining the boundaries of a region
onscreen, and so on.
/* getmaxx 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;
char xrange[80], yrange[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;
/* convert max resolution values to strings */
sprintf(xrange, "X values range from 0..%d", getmaxx());
sprintf(yrange, "Y values range from 0..%d", getmaxy());
/* display the information */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(midx, midy, xrange);
outtextxy(midx, midy + textheight("W"), yrange);
/* clean up */
getch();
closegraph();
return 0;
}