#include <gtk/gtk.h>
#include <cairo.h>
#include <stdlib.h>

#define SIZE 380
#define NBR 20000

static double
frand (void)
{
    return ((double) rand() / RAND_MAX * SIZE);
}

static
expose(GtkWidget *widget, GdkEventExpose *event, gpointer data)
{
	cairo_surface_t *surface;
	cairo_t *cairo;
	int i;
	
	cairo = gdk_cairo_create(widget-> window);

	cairo_rectangle (cairo, 0, 0, SIZE, SIZE);
	cairo_set_source_rgba (cairo, 1, 1, 1, 0);
	cairo_fill (cairo);

	cairo_set_line_join (cairo, CAIRO_LINE_JOIN_ROUND);
	cairo_set_line_cap (cairo, CAIRO_LINE_CAP_ROUND);
	
	cairo_set_line_width (cairo, 1.0);
	cairo_set_source_rgba (cairo, 0., 0., 0., 1.0);
	cairo_move_to (cairo, frand(), frand());
	for (i = 0; i < NBR; i++)
		cairo_line_to (cairo, frand(), frand ());
	cairo_stroke (cairo);
	cairo_destroy (cairo);

	return 0;
}


int main (int argc, char **argv)
{
	gtk_init(&argc, &argv);
	
	GtkWidget *win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	g_signal_connect(win, "delete_event", gtk_main_quit, NULL);
	
	GtkWidget* area = gtk_drawing_area_new(); 
	gtk_widget_set_size_request (area, SIZE, SIZE);
	g_signal_connect(G_OBJECT(area), "expose_event", G_CALLBACK(expose), NULL);
	
	gtk_container_add(GTK_CONTAINER(win), area);
	
	gtk_widget_show_all(win);
	
	gtk_main();
	return 0;
}