I'm trying to adjust user mouse input (slow down/fasten mouse pointer) by calculating and setting the new position of the pointer every mouseMoveEvent().
It looks like the pointer is drawn in it's normal position before mouseMoveEvent() is executed. This results in a bad looking, twitching cursor.
Here is an example of how I would try to keep the pointer in a place, ignoring user input.
Expected behaviour: The pointer stays steady in one place when I move the mouse.
Observed bahaviour: The pointer jiggles. For a fraction of a second, a new pointer is drawn in the position where the mouse is moved, after which it's moved back to it's oldPosition.
void MainWindow::mouseMoveEvent(QMouseEvent *)
{
// [event->accept();] Setting this does not help
// [setCursor(Qt::BlankCursor);] Setting this does not help
QCursor::setPos(oldPosition);
// [setCursor(Qt::ArrowCursor);]
}
P.S. May be there are other ways to adjust mouse sensitivity in qt embedded. Am I doing it right?
Short answer: No.
Unfortunately, there is no way to adjust mouse sensitivity using only QT libraries.
The twitching you are experiencing is because the OS does the work of drawing the mouse pointer, the frequency of which can be different from how frequently you receive mouse move events from the OS.
There is also no way to tell QT or the OS to send you mouse move events before every frame the cursor is drawn.
Workaround: You could hide the mouse pointer completely, and draw your own. This way you will have full control over when the cursor is drawn avoiding the glitches.
Related
I want to have my code read the movement of the mouse and act accordingly, for example, if you are moving your mouse up, you print the mouse is moving up in the console and sort of like that. (I am using Windows 10.)
The problem is, I could find a lot of articles that take the coordinates of the mouse cursor, but couldn't find one that deals with the real raw mouse input. The reason I want to do it this way is that when your cursor hits the border and cannot go further, the cursor position wouldn't change and the program won't recognize the mouse movement even though the mouse is "physically" moving. Another problem is that certain programs can "lock" your cursor to stay in a fixed position. For example, most FPS games do that.
Therefore, I wanted to get the raw input that the sensor of the mouse gives to the computer and utilize them instead of cursor position.
Therefore, I wanted to get the raw input that the sensor of the mouse gives to the computer and utilize them instead of cursor position.
Use the Raw Input API for that. Call RegisterRawInputDevices() to register the target mouse device(s) you want to monitor (there could be multiple connected to the PC), and then handle WM_INPUT messages containing the raw input data from the mouse(s).
At the moment I simply use the WM_MOUSEMOVE message, but it limits the mouse movement to the maximum resolution. So what's the best way of capturing the mouse with Win32 (on a OpenGl window)? I don't want to use freeglut or any extra library.
For games and realtime DirectInput is very suitable, it's moderately hard to use.
That is not core win32 api, the winapi way of getting the input is either GetCursorPos/SetCursorPos driven by your own update loop, so you query and reset with your own frequency.
Or SetCapture and then upon WM_MOUSEMOVE you call SetCursorPos.
The point of setting the cursor pos is to give room for movement so you can get the delta, the amount the cursor moved since the last update and then put it back the cursor into the center of your window.
If you want to be able to capture mouse events after the mouse has existed the window, then you might want to look into the SetCapture function
If your problem is that you want to make a FPS game and you want your character to be able to spin in a continuous motion, then you want to set the mouse position to the center of the window after each mouse move event and handle input based on the difference between the position of the cursor when the mouse move event is fired and the center of the screen. To set the position of the mouse you can use the SetCursorPos function.
Your best bets are to either use DirectInput (which can be a bit of a pain to set up) or RawInput.
There is a fairly comprehensive example available in the Using RawInput page (See example 2).
I'm trying to use SetCursorPos to move the cursor location when it hits the edge of the screen (for a scrubby control); the standard "track until the edge is hit, move cursor to middle of screen" thing.
The problem is that Windows resets the cursor location back to where it was as soon as it gets a mouse event.
For debugging purposes, I made a test app using the code at:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms648380(v=vs.85).aspx#_win32_Using_the_Keyboard_to_Move_the_Cursor
This is showing me the same behavior: I use the mouse to park the cursor in the top left corner of the window (right under the File menu) and use the keyboard to move the cursor off to wherever. But as soon as I touch the mouse, the cursor is right back to the top left corner.
This is obviously less than helpful for my control that uses the mouse to scrub.
How can I make Windows accept my SetCursorPos position as truth?
Thanks!
Using SetCursorPos usually works fine (even though to use it is considered bad style in general.) Some devices such as a Wacom tablet send absolute positions, though. As soon as the device sends a new location, the cursor will jump back. You really can't help this if this is the case.
However, am I right assuming you're doing this because you're trying to detect the speed of the cursor? If so, you should probably use a different API that gives you the low-level values without the need to use the position of the cursor at all. Have a look at DirectInput!
Reading this article "Taking Advantage of High-Definition Mouse Movement" - http://msdn.microsoft.com/en-us/library/windows/desktop/ee418864(v=vs.100).aspx, I surmise that one should use raw input for more precise readings from input devices.
The article states that WM_MOUSEMOVE's primary disadvantage is that it is limited to the screen resolution.
Upon close inspection of the RAWMOUSE structure I see that lLastX and lLastY are long values and you get the delta via them.
To me it looks like WM_MOUSEMOVE and WM_INPUT is the same except with WM_INPUT you do not get acceleration (pointer ballistics) applied.
Are both WM_MOUSEMOVE and WM_INPUT limited to the screen resolution?
If so, what is the benefit of using WM_INPUT?
RAWMOUSE gives you logical coordinates for the mouse based on the mouse's native resolution.
That is, you see the actual movement of the mouse.
Windows will use the mouse speed and acceleration (ballistics) settings to update the cursor position. Because of course the two are not linked - the apparent movement of the mouse must be interpreted to generate a cursor movement else how can more than one mouse be supported?
If you wish to control a pointer, as far as I can tell there is no reason to duplicate the Windows mouse ballistics calculations. Just let windows do it. Therefore for controlling the pointer, you should just use WM_MOUSEMOVE. That is, unless you wish to disable the mouse acceleration settings in your application.
However, if you want to control the player's POV (point of view), or use the mouse to control an in-game object such as a spaceship flight yoke, then the RAWMOUSE data gives you the best possible access to the movement of the mouse, and you can implement your own algorithm to convert that into flight yoke/POV movement.
The main benefit and reason to use it is that that with rawInput you can use two mouses or more. Presently I write small game prototype which is designed to be played by two players with two mouses/mices - It is more complicated but It works and it is not bad because I do nod need to link external libs.
I'm currently writing a c++ console application that grabs the mouse position at regular intervals and sends it to another visual application where it is used to drive some 3d graphics in real time. The visual app is closed source and cannot be altered outside it's limited plug-in functionality.
Currently I'm using the GetCursorPos() function which is easy and fast enough, but I'm running into the issue that all of the data is clipped based on the current screen resolution of 1920x1600 so that all x values are between 0 and 1920 and all y values are between 0 and 1600 no matter how far the mouse is physically moved.
I need to get the mouse position before it's clipped at the edge of the screen, or possibly the deltas which I could use to calculate the current position.
I've seen some references to the windows MouseMove event but I would really not want to implement a window to make it work or especially have it as the active to receive those events.
I'm working in a windows environment and a language change is not feasible.
I might be wrong, but in Win32 land you don't get mouse move messages when the mouse is at the edge of the screen because, well, the mouse isn't moving. The usual way to get an infinite mouse area is to do the following:
Hide the mouse, get exclusive access and record position
Centre mouse to window
When mouse moves, get delta from centre of screen to current position
Centre mouse to window again
The next mouse move should have a delta of (0,0), so ignore it
Go to 3 until end of mouse move operation
Reset position, show the mouse and release exclusive access
If you didn't hide the mouse, then you'd see the mouse moving a small distance and then snapping back to the centre position, which looks nasty.
This method does require a message pump for the mouse move messages so the console application idea probably won't work with this. Can you create a full screen invisible window for grabbing the mouse?
Just get the position, and move it to the center and return the delta yourself
This is how FPS games do it
I don't have any direct experience with raw input, which is probably what you need to tap into. According to MSDN, you have to register the device, then setup your winproc to accept the WM_INPUT messages and then do your calculations based on the raw data.
Here's another relevant link.