x_windows_stream_example.cpp

Free C++ toolkit to facilitate Monte-Carlo simulation. This is a library covered under the LGPL. "MC

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <cstdio>
#include <cstdlib>
#include <cstring>

// include mcsLibre simulation library
#include "mcsLibre.h" 

void draw_stuff(Window win, GC gc, Display *display, int screen, XColor font_color, int stream_base)
{
  // Prepare graphics
  XSetForeground(display, gc, font_color.pixel);
  XDrawString(display, win, gc, 19, 110, "Uniform", strlen("Uniform"));
  XDrawString(display, win, gc, 124, 110, "Normal", strlen("Normal"));
  XDrawString(display, win, gc, 20, 157, "Click in window to", strlen("Click in window to"));
  XDrawString(display, win, gc, 7, 172, "alter random streams.", strlen("alter random streams."));

  // create object for simulation
  mcsLibre sim;

  // random variables
  int ux, uy, nx, ny;
  
  // simulation loop
  int samples = 1000;      // number of simulations
  for (int loopvar = 0; loopvar < samples; loopvar++)
    {
      // get values from streams
      ux = (int) sim.uniform(20, 80, stream_base); 
      uy = (int) sim.uniform(20, 80, stream_base + 1); 
      nx = (int) sim.normal(150, 10, stream_base + 2); 
      ny = (int) sim.normal(50, 10, stream_base + 3); 

      // display results
      XDrawLine(display,win, gc, ux, uy, ux, uy);
      XDrawLine(display,win, gc, nx, ny, nx, ny);
    }
}

main()
{
  Display *display;
  int screen;
  Window win;
  XColor blue;
  unsigned int width = 200;
  unsigned int height = 200;
  XFontStruct *font_info;

  GC gc;
  Colormap cmap;
  XEvent x_event;
  XGCValues values;

  if ( (display = XOpenDisplay(NULL)) == NULL ) 
    {
      perror("Could not open X display.");
      exit(1);
    }

  screen = DefaultScreen(display);
  win = XCreateSimpleWindow(display, RootWindow(display, screen), 0, 0, width, height, 5, BlackPixel(display, screen), WhitePixel(display, screen));
  cmap = DefaultColormap(display, screen);
  XParseColor(display, cmap, "blue", &blue);
  XAllocColor(display, cmap, &blue);
  XParseColor(display, cmap, "ZZ_NO_SUCH_COLOR", &blue);

  if ((font_info = XLoadQueryFont(display, "9x15")) == NULL) 
    {
      perror("Use fixed font\n");
      font_info = XLoadQueryFont(display, "fixed");
    }

  gc = XCreateGC(display, win, (unsigned long)0, &values);
  XSetFont(display, gc, font_info->fid);
  XSetForeground(display, gc, BlackPixel(display, screen));

  XSetStandardProperties(display, win, "Stuff", "QQQ", None, 0, 0, NULL);
  XSelectInput(display, win, ExposureMask | ButtonPressMask);
  XMapWindow(display, win);
 
  int streams = 1;

  draw_stuff(win, gc, display, screen, blue, streams);

  while (1) {
    XNextEvent(display, &x_event);
    switch (x_event.type) {
    case Expose:
      draw_stuff(win,gc,display,screen,blue, streams);
      break;
    case ButtonPressMask:
      streams = streams + 5;
      if (streams >= 90)
	{
	  streams = 1;
	}
      XClearWindow(display, win);
      draw_stuff(win,gc,display,screen,blue, streams);
      break;
    default:
      break;
    }
  }
}