The y aspect factor, *yasp, is normalized to 10,000. On all graphics
adapters except the VGA, *xasp (the x aspect factor) is less than *yasp
because the pixels are taller than they are wide. On the VGA, which has
"square" pixels, *xasp equals *yasp. In general, the relationship between
*yasp and *xasp can be stated as
*yasp = 10,000
*xasp <= 10,000
getaspectratio gets the values in *xasp and *yasp.
/* getaspectratio example */
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
main()
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
int xasp, yasp, midx, midy;
/* 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;
setcolor(getmaxcolor());
/* get current aspect ratio settings */
getaspectratio(&xasp, &yasp);
/* draw normal circle */
circle(midx, midy, 100);
getch();
/* draw wide circle */
cleardevice();
setaspectratio(xasp/2, yasp);
circle(midx, midy, 100);
getch();
/* draw narrow circle */
cleardevice();
setaspectratio(xasp, yasp/2);
circle(midx, midy, 100);
/* clean up */
getch();
closegraph();
return 0;
}