I have created a fake mouse pointer using the xinput command as outlined here which produces a second pointer that hovers in the center of my screen.
I would now like to automate it using the xte command, but unfortunately xte only seems grab control of the hardware mouse that I wish to keep free.
The man page for xte does not have any flags to specify which pointer to take control of.
I was wondering if anybody had any ideas?
NB: The second pointer is purely for me to able to work on the same computer whilst running the graphical pipeline
Edit: So by looking at the xte source I've found references to XQueryPointer
Bool XQueryPointer(display, w, root_return, child_return, root_x_return, root_y_return,
win_x_return, win_y_return, mask_return)
Display *display;
Window w;
Window *root_return, *child_return;
int *root_x_return, *root_y_return;
int *win_x_return, *win_y_return;
unsigned int *mask_return;
//Arguments:
display Specifies the connection to the X server.
w Specifies the window.
root_return Returns the root window that the pointer is in.
child_return Returns the child window that the pointer is located in, if any.
root_x_return
root_y_return Return the pointer coordinates relative to the root window's origin.
win_x_return
win_y_return Return the pointer coordinates relative to the specified window.
mask_return Returns the current state of the modifier keys and pointer buttons.
from the Xlib class, which as you can see returns only the first mouse pointer and does not give option for another.
Edit2: Looking through the libx11-dev source I'm finding mentions of it at ./src/QuPntr.c and Xlibint.h, but the code is getting harder to read and I'm out of my depth here
xinput makes use of the XI2 extension to allow for multiple pointers.
This library (X11/extensions/XInput2.h) provides functions prefixed by "XI" which accept a device parameter (the same referenced by xinput --list), for instance XIQueryPointer, XIWarpPointer or XIGetClientPointer.
Thus you can control your fake pointer programmatically if your automation tool doesn’t support XI2.
In a simpler way, it could suffice to xinput --reattach the hardware device (a slave device) to the new pointer (a master device).
Very late answer I know, but I came across this question via web search so I add what I know for reference.
Actually there isn't any mention of XQueryPointer inside the source code of xte.c (there are only a few inside xmousepos.c, which is code for a different tool).
I checked a few older versions that existed before you asked the question.
The relevant functions are XIWarpPointer and XTestFakeDeviceButtonEvent. As seen here in the reduced source code:
#include <X11/Xlib.h>
#include <X11/extensions/XInput2.h>
#include <X11/extensions/XTest.h>
int main (int argc, char *argv[])
{
int delta_x = 500, delta_y = 160;
Display *display = XOpenDisplay(0);
Window root = DefaultRootWindow(display);
XIWarpPointer(display, 14, None, root, 0, 0, 0, 0, delta_x, delta_y);
XDevice *device = NULL;
device = XOpenDevice(display, 16);
XTestFakeDeviceButtonEvent(display, device, 1, True, 0, 0, CurrentTime);
XTestFakeDeviceButtonEvent(display, device, 1, False, 0, 0, CurrentTime);
XCloseDisplay(display);
}
which does the same thing as xte -i 16 "mousemove 500 160" "mouseclick 1".
But what might bother you (at least it bothers me): Windows that got clicked gain focus, effectively unfocusing the window that you were working on.
Actually I asked a question that asks for an alternative to XTestFakeDeviceButtonEvent just recently (Sending a button press event for a second pointing device; I also provided some example code that actually performs mouse clicks without giving focus to a window, so it's possible but dunno how it's done with another pointing device)..
An alternative might be to work with multiple X sessions like this user did it: Controlling multiple pointers with Xlib or xinput in ubuntu/linux. Sadly he hasn't shared any code.
I have some hope with uinput (https://www.kernel.org/doc/html/v4.12/input/uinput.html) but haven't tried it yet.
Related
I have a touch screen with events at /dev/input/event12 and /dev/input/event13. /dev/input/event12 is the main touch input, and in essence, I'd like to send instructions to the event directly to control behavior (ie, click location etc).
Tools like xdotool do not want to work because this device is being set as a second pointer (see: https://dwm.suckless.org/multi-pointer/) and the recommendation of using xinput set-cp <window> <master> does not appear to work as expected.
A solution was found using Python and Python-evdev. Using evdev you can assign the device and pass parameters within the allowed functions. In my case it is as follows:
device.write(e.EV_KEY, e.BTN_TOUCH, 1)
device.write(e.EV_KEY, e.BTN_TOUCH, 0)
device.write(e.EV_SYN, 0, 0)
I can copy the contents of the root window to an xcb_image_t in client (ie. CPU) memory using xcb_image_get() (regardless of its map status, although presumably the root window is always mapped?). Eg:
xcb_image_t* xcb_img = xcb_image_get(xcb_connection, xcb_screen->root, 0, 0, xcb_screen->width_in_pixels, xcb_screen->height_in_pixels, 0x00ffffff, XCB_IMAGE_FORMAT_Z_PIXMAP);
Now the pixels of the root window are in xcb_img->data.
But I'm trying to copy the contents of the root window to an xcb_pixmap_t (in server memory), and it's not working (the call doesn't
fail, but it returns garbage, as if the window wasn't mapped):
xcb_void_cookie_t copy_cookie = xcb_copy_area_checked(xcb_connection, xcb_screen->root, xcb_pixmap, xcb_gc_null, 0, 0, 0, 0, xcb_screen->width_in_pixels, xcb_screen->height_in_pixels);
xcb_generic_error_t* copy_error = xcb_request_check(xcb_connection, copy_cookie);
if(copy_error)
exit(1);
However, it works for other windows that happen to be mapped (and it fails for subregions of those windows that are occluded by other windows, in the sense that the copy returns garbage.)
I understand that a window needs to be mapped in order to have meaninful contents. This leads me to think that the root window is never mapped (or something).
All I want is to copy the contents of the display (ie. the pixels that are currently being shown in the physical display/monitor) to an xcb_pixmap_t (or, equivalently, to an Xlib Pixmap). How can I do this? (It works so easily for xcb_get_image()...)
You want your GC to have SubwindowMode set to IncludeInferiors (default is ClipByChildren).
From the X11 protocol description:
For ClipByChildren, both source and destination windows are additionally clipped by all viewable InputOutput children. For IncludeInferiors, neither source nor destination window is clipped by inferiors. This will result in including subwindow contents in the source and drawing through subwindow boundaries of the destination. The use of IncludeInferiors with a source or destination window of one depth with mapped inferiors of differing depth is not illegal, but the semantics is undefined by the core protocol.
https://www.x.org/releases/X11R7.5/doc/x11proto/proto.html
What this means is that with ClipByChildren, you are only copying from the window that you used as the source. If the window has subwindows, the pixels "in there" are not owned by the window you are using as the source. Thus, X11 assumes you do not want those pixels.
I've been googling for quite a long time and I just can't find any information on how to get screen_number for every screen connected to computer. Here I found a list of macros and some of them (like for example ScreenOfDisplay(display, screen_number) ) use argument screen_number. However there is no such macro that could give me a list of those numbers (one for every connected screen). I know how to get number of default screen (DefaultScreen() ) and count of all screens ( ScreenCount() ) but what about other screens? I noticed that screen_number of default screen is 0, although I have only one screen connected to my computer so I can't really test what happens when there are more of them. I think that screen_number could be assigned in a very simple way which is screen_number=0 for first screen,screen_number=1 for second,screen_number=2 for third and so on but as I said... I can't test wheather it's true and even if I had multiple screens how could I be sure that it works like this for all computers .Please ,if anyone of you has more experience with X11 and knows all details about how it works,tell me if I am right.
The ScreenCount(dpy) macro and int XScreenCount(Display*) function both return the number of screens connected to the display. Valid screen numbers are 0 to ScreenCount(dpy)-1. Macros in Xlib.h confirm:
#define ScreenCount(dpy) (((_XPrivDisplay)dpy)->nscreens)
#define ScreenOfDisplay(dpy, scr) (&((_XPrivDisplay)dpy)->screens[scr])
Your source (2.2.1. Display Macros) provides enough information. Normally the default screen-number is 0, e.g., when connecting to the local host you could use :0.0 as indicated in the documentation for XOpenDisplay.
That is "normally". If you run VNC, normally that runs on a different display (the first 0 in the simple connection string shown).
But (reading the documentation), when an application calls XOpenDisplay, it asks for the given screen-number (which the X server may/may not honor):
screen_number
Specifies the screen to be used on that server. Multiple screens can be controlled by a single X server. The screen_number sets an internal variable that can be accessed by using the DefaultScreen() macro or the XDefaultScreen() function if you are using languages other than C (see "Display Macros").
I want to mask the moving objects from video.
I found that OpenCV has some built-in BackgroundSubtractors which could possibly saving my time a lot. However, according to the official reference, the function:
void BackgroundSubtractorMOG2::operator()(InputArray image, OutputArray fgmask, double learningRate=-1)
should output a mask, fgmask, but it doesn't. The fgmask variable will contain the "contour of the mask" instead after invoking above method. That's weird. All I want is a simple closed region filled with white color(for example) to represent the moving objects. How could I do that?
Any reply or recommendation would be very appreciate. Thanks a lot.
Here's my code:
int main(int argc, char *argv[])
{
cv::BackgroundSubtractorMOG2 bg = BackgroundSubtractorMOG2(30,16.0,false);
cv::VideoCapture cap(0);
cv::Mat frame, mask, _frame, _fmask;
cvNamedWindow("mask", CV_WINDOW_AUTOSIZE);
for(;;)
{
cap >> frame;
bg(frame,fmask,-1);
_frame = IplImage(frame);
_fmask = IplImage(fmask);
cvShowImage("mask", &_fmask);
if(cv::waitKey(30) >= 0) break;
}
return 0;
}
A snapshot of the output video is:
p.s. My working environment is OpenCV2.4.3 on OSX 10.8 and XCode 4.5.2 with apple LLVM compiler 4.1.
If you want to acquire the whole objects filled with white pixels in the foreground then I would ask you to tell me something about your experience.
My question is, for the code, you mentioned above, do you get more white pixels when you generate more motion in front of your camera?
If yes then there are two paramenters to learn about for your requirement.
First is the History parameter. which you have configured as 30 in the constructor BackgroundSubtractorMOG2(30,16.0,false);. You can test this param by incresing, say to 300. It will maintain the motion history of the object in the foreground. So if you have moved completely from your starting location within the 300 frames then you will get whole object covered with white pixels as you want. but it will be erased gradually. So it cannot give you the 100% solution.
The second parameter is called learning rate. In the code you mentioned bg(frame,fmask,-1); where -1 is your learning rate. you can set it to 0.0 to 1.0 and default is -1. When you set it 0, you will get what you want for the objects which are not part of the frame in the starting of the video. You can call this kind of object "foreign objects". You will get foreign object covered with white pixels.
Explore your testing from the information I have mentioned above and share your experience.
I'm using MFC's doc/view architecture to implement printing. I use double buffering, I draw everything onto my backbuffer which is DIB bitmap. Than I use StretchBlt to copy that DIB onto printer DC.
The strange thing is - print preview is working well! When I print on virtual PDF printer, it is working well! But when I print on actual printer (I'm testing on two different printers - same results) - it just prints "garbage". The "garbage" means sometimes it prints totally black page, sometimes it prints the first few pages repeatedly, i.e. it prints wrong part of DIB, just like if I messed up coordinates to StretchBlt, but I didn't mess anything up, I checked multiple times, plus why is print preview is working flawlessly then?
I tried many variations:
Using memory DC compatible to screen DC, when printing.
Using memory DC compatible to printer DC, and selecting my DIB into it.
Using memory DC compatible to printer DC, and using dedicated DIB onto which I copy my original backbuffer DIB.
etc.
But the results are same. Below is the code where i create the DIB. I think the DIB format might be the problem, so please advice if there is something wrong with it. I tried both 24 bits and 32 bits as values for bmiHeader.biBitCount.
// Setup proper backbuffer:
_CleanupBackBufferStuff();
_pMemDc = new CDC;
_pMemDc->CreateCompatibleDC(&aDC);
BITMAPINFO bmi;
memset(&bmi, 0, sizeof(BITMAPINFO));
bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmi.bmiHeader.biWidth = _sizeBackBuffer.cx;
bmi.bmiHeader.biHeight = -_sizeBackBuffer.cy; // top-down
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = 24; // Tried 32 as well
bmi.bmiHeader.biCompression = BI_RGB;
unsigned char *pBitmapRawBits = 0;
HANDLE hMemBitmap = CreateDIBSection(aDC.GetSafeHdc(), &bmi, DIB_RGB_COLORS, (void**)&pBitmapRawBits, 0, 0);
_hOldSelBitmap = (HBITMAP)_pMemDc->SelectObject(hMemBitmap);
Also here is the code for StretchBlt (nothing special here):
pDC->SetStretchBltMode(HALFTONE);
SetBrushOrgEx(pDC->GetSafeHdc(), 0, 0, 0);
BOOL bSuccess = pDC->StretchBlt(rectClipBoxPlayground.left, rectClipBoxPlayground.top, rectClipBoxPlayground.Width(), rectClipBoxPlayground.Height(),
_pMemDc, rectClipBoxBackBuffer.left, rectClipBoxBackBuffer.top, rectClipBoxBackBuffer.Width(), rectClipBoxBackBuffer.Height(), SRCCOPY);
StretchBlt returns true, also (pDC->GetDeviceCaps(RASTERCAPS) & RC_STRETCHBLT) is true as well.
UPDATE: After Adrian's comment, I changed my code to use StretchDIBits. The problem is still the same! Below is the code I'm using currently:
// Copy back buffer to screen dc:
pDC->SetStretchBltMode(HALFTONE);
SetBrushOrgEx(pDC->GetSafeHdc(), 0, 0, 0);
HBITMAP hMemBitmap = (HBITMAP)_pMemDc->SelectObject(_hOldSelBitmap);
DWORD dwLines = StretchDIBits(pDC->GetSafeHdc(),
rectClipBoxPlayground.left, rectClipBoxPlayground.top, rectClipBoxPlayground.Width(), rectClipBoxPlayground.Height(),
rectClipBoxBackBuffer.left, _sizeBackBuffer.cy - rectClipBoxBackBuffer.top - rectClipBoxBackBuffer.Height(), rectClipBoxBackBuffer.Width(), rectClipBoxBackBuffer.Height(),
_pBitmapRawBits, &_bitmapInfo, DIB_RGB_COLORS, SRCCOPY);
_pMemDc->SelectObject(hMemBitmap);
It still behaives like the source coordinates are incorrect. It either prints one of first few pages (no matter what page I select), or prints almost-fully-black pages. The print preview is working perfectly, so this makes me think there should be no problems with my coordinate-calculation code. It works in preview, it works with virtual (pdf) printer, it fails when printing on actual printer. What the hell?....
Make sure you don't have the DIBSECTION selected into more than one DC at a time. That can cause all sorts of unpredictable behavior.
For printing, you can probably bypass the memory DC altogether if you keep your bmi and pBitmapRawBits handy. Make sure the DIBSECTION is not selected into any DC, and then call SetDIBitsToDevice or StretchDIBits to transfer the image to the printer DC.
If you're still having problems, you might want to check the capabilities of your printers. Not all the drivers support all the bitmap transfer methods. I believe the printing system is supposed to hide those differences from you, but perhaps not. Call GetDeviceCaps on your printer DC, and check the RASTERCAPS for RC_BITBLT and friends.