webcam.c

   1 /*
   2  * webcam.c - fetch data from webcam
   3  *
   4  * author: hackbard
   5  *
   6  */
   7
   8 /* includes */
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13 #include <X11/Xlib.h>
  14 #include "minirgb.h"
  15
  16 /* variables */
  17 Display *display;
  18
  19 /* main routine */
  20 int main(int argc,char **argv) {
  21
  22  /* local variables */
  23  int screen_id,screen_width,screen_height;
  24  Window root_window,win;
  25  unsigned long white_pixel,black_pixel;
  26
  27  /* opening display */
  28  display=XOpenDisplay(NULL); /* connect on local display :0 */
  29  if(display==NULL) {
  30   printf("cannot connect to xserver!\n");
  31   exit(EXIT_FAILURE);
  32  }
  33
  34  /* getting basic xserver information */
  35  // our screen id
  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);
  45
  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);
  51
  52  /* open a window */
  53  win=XCreateSimpleWindow(display,
  54                          root_window,
  55                          0,0, // coordinates
  56                          screen_width/3,screen_height/3,
  57                          500,black_pixel,white_pixel);
  58
  59  /* map the window */
  60  XMapWindow(display,win);
  61
  62  /* flush */
  63  XFlush(display);
  64
  65  /* wait a bit */
  66  sleep(5);
  67  printf("blabla ....\n");
  68
  69  /* close display */
  70  XCloseDisplay(display);
  71
  72 }