setviewport

Syntax

#include <graphics.h>
void setviewport(int left, int top, int right, int bottom, int clip);

Description

setviewport establishes a new viewport for graphics output.

The viewport corners are given in absolute screen coordinates by (left,top) and (right,bottom). The current position (CP) is moved to (0,0) in the new window.

The parameter clip determines whether drawings are clipped (truncated) at the current viewport boundaries. If clip is nonzero, all drawings will be clipped to the current viewport.

Return Value

If invalid input is passed to setviewport, graphresult returns -11, and the current view settings remain unchanged.

See also

clearviewport

getviewsettings

graphresult

Example

/* setviewport example */ 

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

#define CLIP_ON 1            /* activates clipping in viewport */

int main(void)
{
   /* request autodetection */
   int gdriver = DETECT, gmode, errorcode;


   /* 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 */
   }

   setcolor(getmaxcolor());

   /* message in default full-screen viewport */
   outtextxy(0, 0, "* <-- (0, 0) in default viewport");

   /* create a smaller viewport */
   setviewport(50, 50, getmaxx()-50, getmaxy()-50, CLIP_ON);

   /* display some text */
   outtextxy(0, 0, "* <-- (0, 0) in smaller viewport");

   /* clean up */
   getch();

   closegraph();
   return 0;
}