Qt與XComposite問題

我想寫一個簡單的程序，它將所有的窗口重定向到後臺緩存（作爲複合管理器），然後將它們寫入pixmap並保存到磁盤。但我得到這個錯誤：Qt與XComposite問題

(.text.startup+0x5e):-1: error: undefined reference to `XCompositeRedirectSubwindows' 
(.text.startup+0x171):-1: error: undefined reference to `XCompositeNameWindowPixmap' 
:-1: error: collect2: ld returned 1 exit status

下面是代碼：

#include <QApplication> 
#include <QDebug> 
#include <X11/Xlib.h> 
#include <QPaintDevice> 
#include <QX11Info> 
#include <X11/Xlib.h> 
#include <X11/Xutil.h> 
#include <X11/Xatom.h> 
#include <X11/extensions/Xcomposite.h> 
#include <X11/extensions/Xrender.h> 
#include <X11/extensions/Xdamage.h> 

#include <QPixmap> 
#include <QWidget> 

int main(int argc, char *argv[]) 
{ 
    QApplication app(argc, argv); 
    app.setGraphicsSystem("native"); 

    Picture frontBuffer; 
    XRenderPictFormat *format; 
    Window rootWindow; 
    int depth; 

    Display *dpy = XOpenDisplay(getenv("DISPLAY")); 
    rootWindow = XRootWindow(dpy, XDefaultScreen(dpy)); 

    depth = DefaultDepth(dpy, DefaultScreen(dpy)); 

    // Redirect all the windows 
    XCompositeRedirectSubwindows(dpy, rootWindow, CompositeRedirectManual); 

    // Get the format 
    format = XRenderFindVisualFormat(dpy, DefaultVisual(dpy, DefaultScreen(dpy))); 

    XRenderPictureAttributes pa; 
    pa.subwindow_mode = IncludeInferiors; 

    // Creating front buffer 
    frontBuffer = XRenderCreatePicture(dpy, rootWindow, format, CPSubwindowMode, &pa); 

    uint nwindows; 
    Window root_return, parent_return, *windows; 

    XQueryTree(dpy, rootWindow, &root_return, 
        &parent_return, &windows, &nwindows); 

    for (uint i = 0; i < nwindows; i++) { 
      XWindowAttributes attr; 
      if (!XGetWindowAttributes(dpy, windows[i], &attr)) 
        continue; 

      Pixmap pix = XCompositeNameWindowPixmap(dpy, windows[i]); 

      Picture pic = XRenderCreatePicture(dpy, pix, format, 0, 0); 

      QPixmap pixmap(540, 900); 
      XRenderComposite(dpy, PictOpSrc, pic, None, pixmap.x11PictureHandle(), 
              0, 0, 0, 0, 0 , 0, 540, 900); 
      pixmap.save(QString::number(i)+".png", "PNG"); 
     } 
    } 
    XFree(windows); 
    return app.exec(); 
}

來源

2011-08-31 Islam Wazery