Function:cs2srcb

void cs2srcb(void *remcb);

setenv S2PLOT_REMOTEPORT 3333

telnet localhost 3333
S2 setcolor 0.9,0.1,0.5

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

unsigned int tid;

float _bb_r, _bb_g, _bb_b;

int remote_cb(char *data);
void cb(double *t, int *kc);

int main(int argc, char *argv[])
{
   int width = 16, height = 16;         /* Dimensions of texture */
   int i, j;                            /* Loop variables */
   int idx;                             /* Index into texture array */
   unsigned char *tex;                          /* Array of texture values */

   srand48((long)time(NULL));                   /* Seed random numbers */

   s2opend("/?",argc,argv);                     /* Open the display */
   s2svp(-1.0,1.0, -1.0,1.0, -1.0,1.0);         /* Set the viewport coords */
   s2swin(-1.0,1.0, -1.0,1.0, -1.0,1.0);        /* Set the window coordinates */
   s2box("BCDE",0,0,"BCDE",0,0,"BCDE",0,0);     /* Draw a bounding box */

   tid = ss2ct(width, height);          /* Create a new texture */
   tex = ss2gt(tid, &width, &height);   /* Get the texture */

   for (j=0;j<height;j++) {
      for (i=0;i<width;i++) {
         idx = (j*width + i) * 4;               /* Stored as (r,g,b,alpha) */
         tex[idx  ] = 255;                      /* solid red */
         tex[idx+1] = 255;                      /* Green */
         tex[idx+2] = 255;                      /* Blue */
         tex[idx+3] = 127 * drand48()+128;      /* Random transparency */
      }
   }
   ss2pt(tid);                          /* Push texture for usage */

   _bb_g = 0.7;
   _bb_b = 0.9;

   cs2scb(&cb);                         /* Install a callback */
   cs2srcb(&remote_cb);                 /* Install remote callback */

   s2show(1);                           /* Open the s2plot window */

   return 1;
}

void cb(double *t, int *kc)
{
   float x = 0.0, y = 0.3, z = 0.4;                     /* Location */
   float isize = 0.02;                                  /* Texture scale */
   float str_x = 0.0, str_y = 0.0, str_z = 0.0;         /* No stretch */
   float alpha = 0.9;                                   /* Alpha channel */
   char trans = 't';                                    /* Transparency */

   ds2bb(x,y,z, str_x,str_y,str_z, isize, _bb_r, _bb_g, _bb_b, tid, alpha, trans);
                                        /* Draw the billboard */
}

int remote_cb(char *data) {
  // this remote callback will receive strings coming in on
  // the S2PLOT_REMOTEPORT port.

  char *contype, *ctype, *cargs;

  contype = strtok(data, " ");

  // for this demo, we will only parse commands preceded by "S2"
  if (!contype || strcmp(contype, "S2")) {
    // return 0 to indicate we have not "consumed" this event
    fprintf(stderr, "remote_cb: no valid command prefix\n");
    return 0;
  }

  ctype = strtok(NULL, " ");
  if (!ctype) {
    fprintf(stderr, "remote_cb: no command present\n");
    return 0;
  }

  int consumed = 0;

  // the only command we accept is "setcolor" to set the
  // billboard color
  if (!strcmp(ctype, "setcolor")) {
    cargs = strtok(NULL, " ");
    if (!cargs) {
      fprintf(stderr, "remote_cb: no argument for setcolor present\n");
      return 0;
    }
    float vr, vg, vb;
    sscanf(cargs, "%f,%f,%f", &vr, &vg, &vb);

    if ((vr >= 0.) && (vr <= 1.) &&
        (vg >= 0.) && (vg <= 1.) &&
        (vb >= 0.) && (vb <= 1.)) {
      _bb_r = vr;
      _bb_g = vg;
      _bb_b = vb;
    }


    consumed = 1;
  } else {
    fprintf(stderr, "remote_cb: unknown command %s\n", ctype);
  }

  return consumed;
}