setactivepage

Sets active page for graphics output.

Defined in header <graphics.h>

Syntax

#include <graphics.h>
void far setactivepage(int page);

Portability

Remarks

setactivepage makes page the active graphics page. All subsequent graphics output will be directed to that graphics page.

The active graphics page might not be the one you see onscreen, depending on how many graphics pages are available on your system. Only the EGA, VGA, and Hercules graphics cards support multiple pages.

Return value

None.

See also

• setvisualpage

Example

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

int main (void)
{
   /* select driver and mode  that supports multiple pages */
   int gdriver = EGA, gmode  = EGAHI, errorcode;
   int X, y, ht;
   /* initialize graphics and  local variables '/
   initgraph(&gdriver, &gmode,  "");

   /* read result of initialization  */
   errorcode = graphresult ();
   if (errorcode  != grOk)    /* an error occurred V
   {
      printf ("Graphics error: %s\n", grapherrormsg(errorcode)
      printf("Press any key to halt:");
      getchO ;
      exit(l);                /* terminate with an error code */

   X = getmaxx () / 2 ;
   y = getmaxy () / 2;
   ht = textheight("W") ;
/*  select the off screen page  for drawing */
setactivepage (1);
/* draw a line on page  #1 */
line(0, 0, getmaxxO,   getmaxy ()) ;

/* output a message on page  #1 */
settextjustify (CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y,  "This is page #1:");
outtextxy(x, y+ht,  "Press any key to halt:");
/* select drawing to page     7
setactivepage (0);

/* output a message  on page  #0 */
outtextxy(x, y,  "This is page #0.");
outtextxy(x, y+ht,  "Press any key to view page #1:
getchO ;

/* select page #1 as the visible  page */
setvisualpage(l) ;

/* clean up */
getchO ;
closegraph() ;
return 0;

Differences from modern implementations

Nothing recorded yet.

Modern references

• Microsoft C runtime (search)

These are search links, not yet checked by hand.

Stable link: /3.1/graphics.h/setactivepage/ · short form /3.1/setactivepage/