2 * webcam.c - fetch data from webcam
20 int main(int argc,char **argv) {
23 int screen_id,screen_width,screen_height;
24 Window root_window,win;
25 unsigned long white_pixel,black_pixel;
28 display=XOpenDisplay(NULL); /* connect on local display :0 */
30 printf("cannot connect to xserver!\n");
34 /* getting basic xserver information */
36 screen_id=DefaultScreen(display);
37 // dimensions of screen
38 screen_width=DisplayWidth(display,screen_id);
39 screen_height=DisplayHeight(display,screen_id);
40 // how to draw white/black pixels */
41 white_pixel=WhitePixel(display,screen_id);
42 black_pixel=BlackPixel(display,screen_id);
43 // the screen's root window id
44 root_window=RootWindow(display,screen_id);
46 /* print basic xserver settings */
47 printf("screen ID: %d\n",screen_id);
48 printf("dimensions: %d x %d\n",screen_width,screen_height);
49 printf("white color -> %d\n",white_pixel);
50 printf("black color -> %d\n",black_pixel);
53 win=XCreateSimpleWindow(display,
56 screen_width/3,screen_height/3,
57 500,black_pixel,white_pixel);
60 XMapWindow(display,win);
67 printf("blabla ....\n");
70 XCloseDisplay(display);