I have a Windows 7 system, a regular monitor as the primary display (serving as a desktop, etc.), and an additional screen attached to the same graphics card.
I want to write a program that takes control of the secondary display and uses it for fullscreen OpenGL rendering. I tried to enumerate displays with EnumDisplaySettings, pick the secondary display, create a device context associated with the display, set the pixel format on the DC, and create a WGL context associated with it. I can get this far without errors, but then the call to wglMakeCurrent fails for no apparent reason (return value is 0, GetLastError() is 0, and OpenGL does not function.)
The only way I could get it to work is to extend the desktop onto the secondary display (manually, from Windows display settings), create a window and move it onto the secondary display. Which is tolerable but undesirable (I don't want the secondary display to interfere with the desktop. For example, in this setup, I can move the mouse cursor from the desktop into the secondary display.) Is there a way to avoid this?
More generally, in order to get OpenGL to work on a display, do I need (1) to have the display attached to the desktop (or "a" desktop?), and/or (2) to have a window of my own on that display?
P.S. It seems that I might be able to get this to work with a third-party library such as glfw3, but I don't want extra baggage (I don't need 90% of functionality of glfw3) and I'd prefer to get this done directly through native API calls if possible.
Unfortunately the Windows graphics driver model does not allow to use displays independently. You will have to extend the desktop to the second display and create a fullscreen window on it. When it comes to constraining the mouse, the usual way is to hook into the system mouse events and whenever the mouse pointer is moved into the secondary screen remove it back to the primary screen.
Related
So I`m very new to win32ui, basically just starting. I was once using BitBlt wit python win32api module and as far as I remember to draw on top of display (so any application - if they are opened) I had to get specific context handle. But my memory is hazy on whether it simply was NULL or was it some specific context? Null doesn't seem to work, so I wonder how to obtain that general context? I really want to avoid to create fully transparent un blocking window.
The GetDC API allows you to get a device context for any given window. Alternatively,
If [hWnd] is NULL, GetDC retrieves the DC for the entire screen.
You can use the device context for the entire screen to read from, reliably (with restrictions). Rendering into a device context for a window you do not own won't be reliable, though. While it won't fail straight away, the window owner can overwrite your rendering at any point. There's no way for you to even be notified about this.
If you need to render on top of the screen you will have to create a top-most (transparent) window yourself, and use its device context. Make sure you ask the question: What if two programs did this?
I have founds some resource like this dealing with the subject of attaining multiple cursors on windows for more than one mouse attached to the system. My requirement is a little simpler but I need some inputs on it.
1) What I want is to invoke an application (lets say IE) and do mouse activity(hovering , clicking etc) on it. All of this while there should be no disturbance to the system cursor , which should be free to be used by the user of the desktop.
2)I understand that this can not be done using the windows cursor apis as the documentation always mentions "the cursor" and there is no concept of multiple cursors inbuilt.
3)
This leaves me to drawing a cursor on the target window. A bitmap perhaps and to move it randomly? What APIs will be of use here?
How do I simulate the visual effects that are actually done my actual cursor movement. Do I need to send messages to the target
window like WM_MOUSEMOVE , WM_SETCURSOR etc.?
Does sending mouse messages to the other window interfere with the mouse activities that the user is involved in currently? The
intention is not to disturb the user while the application runs.
Thanks for your inputs.
Create a separate window for each extra mouse that is installed, and put an image of the desired cursor in each window. Then use the Raw Input API to monitor activity on the extra mouses and move your windows around as needed, and use mouse_event() or SendInput() to send out your own mouse events (movements, clicks, etc) as needed.
We're making a user-space device driver for OS X that moves the cursor using Quartz Events, and we ran into a problem when games — especially ones that run in a windowed mode — can't properly capture the mouse pointer (= contain/keep it within the boundaries of their windows). For example, it would go outside the game window and click on the desktop or nearby inactive applications.
We could fix this if only we could detect when an active application calls CGAssociateMouseAndMouseCursorPosition.
How would you do this? Any ideas are appreciated.
I dont know if this can help you
There is an option called Focus Follows Mouse
Focus Follows Mouse - The Mouse pointer will grab automatically change focus to a new window inisde this one app if you mouse over it, instead of having to click a window to get focus, then clicking to do something.
http://wineskin.urgesoftware.com/tiki-index.php?page=Manual+4.6+Advanced+-+Options
I have written a few different mouse logical layers (for bridging different input devices, etc.). I have found that hooking into the OS level WM_INPUT event is a sure way of getting very real-time mouse position information. There is also a less rigorous solution of just polling the mouse data you need from one of Windows' very primitive DLLs. They are lightning fast. You could poll on a 10ms timer and never see performance loss on a modern machine.
You can probably figure out why I am asking this question. Even if not, it's very simple.
My question is whether it is possible to detect the use of SetCursorPos() on one's own application, without scanning other running applications for any calls to this API.
For example, if I have my cursor in a window and I call SetCursorPos(), can this window in anyway know that the cursor placement is not directly from the mouse (raw input)?
I am not oblivious to the fact that you can 'know' whether a mouse input is raw simply by checking how the position alters; for example, if the position changes from 100(X) & 100(Y) to 500(X) and 500(Y), without moving through each individual location between these two, then with certainty, something has altered the mouse position.
If anyone of you know of a way to produce 'raw mouse input', without any application being able to tell the difference between the output from a function, and that from a mouse--if there is such a difference--then that'd suffice, too.
Of course, whenever I move my mouse, the operating system I am using detects this and then appropriately moves the cursor accordingly. In practice, I should be able to alter this low level functionality as to my will?
There is no way for a window to directly determine how the mouse was moved. External applications could be using SetCursorPos(), but they could also be using lower level functions like mouse_event() or SendInput() instead. By the time the notification reach the target window, the OS has already normalized the data and any source information is lost If you really needed to detect use of SetCursorPos() or other functions, you would have to directly hook into those functions in every running process. Alternatively, you might try registering for "Raw Input" via RegisterRawInputDevices() and see if you get a corresponding notification from the mouse hardware directy, assumine those simulating functions do not trigger Raw notifications as well.
It is possible to use the SetWindowPos API on Windows to keep a windows always on top of other windows, and there are many questions on StackOverflow dealing with this.
It is possible to keep only part of a Window always visible? I.e. specify a clipping region inside an existing window, and keep only that part visible?
A use case would be the following (on Windows):
User clicks on icon to run app.
User highlights a portion of the screen to focus on (similar to the Snipping Tool on Windows 7)
The highlighted part of the screen remains always visible, even when other windows/programs are moved over the selected region.
I know the issues that would spring up with having other applications that are also set to being topmost. Just curious if this is even possible?
Even if you change part of your window to be transparent to what's below (with a clipping region) it's still going to take all the mouse clicks, etc. that occur over the transparent part.
Your best bet is to create a new smaller window and make it top-most while hiding the main one.