Function:ss2qfra

float ss2qfra(void);

#include <stdio.h>
#include <stdlib.h>
#include "s2plot.h"

void cb(double *t, int *kc)
{
   ss2sas(1);                                   /* Autospin mode on */

   static int lkc = 0;                          /* Count of key presses */

   if (lkc != *kc) {                            /* Space bar pressed? */
     ss2sfra(drand48()*90-45.0);                /* Rotate the centre up */
   }

   float fra = ss2qfra();               /* Query fisheye rotation angle */
   s2sch(5);
   char string[32];
   sprintf(string,"Fisheye angle = %.2f",fra);  /* Write to string */
   s2textxy(0,0,0,string);                      /* Display text */

   lkc = *kc;                                   /* Update count */
}


int main(int argc, char *argv[])
{

   fprintf(stderr,"Press <spacebar> to change fisheye rotation angle\n"); 
   s2opend("/S2FISH",argc, argv);               /* Open the display: fisheye */
   s2swin(-1.,1., -1.,1., -1.,1.);              /* Set the window coordinates */

   ss2tc(0);                                    /* Don't allow translation */

   cs2scb(cb);                                  /* Install dynamic callback */
   s2show(1);                                   /* Open the s2plot window */
   
   return 1;
}