I have a Direct2D window which paints fine when in focus; however, when focus moves to another window (same application or another), the entire window goes black. I pinned the issue down to the use of ID2D1HwndRenderTarget::Clear. This function is vital to my application as without it, painting becomes rather... weird.
Is there a way an un-focused Direct2D window can paint as normal (note: WM_PAINT is being called as usual, as is Clear, BeginPaint, etc. all without error)
Thanks in advance.
From MSDN,
Handling Device Loss
While your program is running, the
graphics device that you are using
might become unavailable. For example,
the device can be lost if the display
resolution changes, or if the user
removes the display adapter. If the
device is lost, the render target also
becomes invalid, along with any
device-dependent resources that were
associated with the device. Direct2D
signals a lost device by returning the
error code D2DERR_RECREATE_TARGET from
the EndDraw method. If you receive
this error code, you must re-create
the render target and all
device-dependent resources.
Please check the link for more info. http://msdn.microsoft.com/en-us/library/ff684174(VS.85).aspx
With my experience with DirectX, if the screen turns back its because DX lost the device it was 'painting' to. This happens a lot - for instance - when switching between a full-screen DirectX window to another application, and vice-versa.
So what you need to do is re-intialize the DX device so it can resume painting operations.
This might help some more (not my website, but a quick Google search turned it up)
http://www.programmersheaven.com/2/FAQ-DIRECTX-Avoid-task-switching
Related
I have a wxWidgets application that has a number of child opengl windows. I'm using my own GL canvas class, not the wx one. The windows share their OpenGL context.
I don't think the fact it is wxwidgets is really relevant here.
The opengl windows are children of a windows that are siblings of one another, contained within a tab control. Kind of an MDI style interface, but it is not an MDI window.. Each one can be individually resized. All works lovely unless Aero is enabled and the DWM is active.
Resizing any window (not even the opengl ones) causes all of the opengl windows to flicker occasionally with a stale backing-store view that contains whatever rubbish has been on the screen at that point that is not opengl. This ONLY happens with Aero enabled.
I'm pretty certain that this is the DWM not actually having the opengl contents on its drawing surface backing store and the window not being repainted at the right moment.
I've tried so many things to get round this, I do have a solution but it is not very nice and involves reading the framebuffer with glReadPixels into a DIB and then blitting it to the paint DC in my onPaint routine. This workaround is only enabled if DWM is active but I'd rather not have to do this at all as it hurts performance slightly (but not too bad on a capable system - the scenes are relatively simple 3d graphs). Also mixing GDI and opengl is not recommended but this approach works, surprisingly. I can live with it for now but I'd rather not have to. I still have to do this in WM_PRINT if I want to take a screenshot of the child window anyway, I don't see a way around that.
Does anyone know of a better solution to this?
Before anyone asks I definitely do the following:
Window class has CS_OWNDC
WM_ERASEBACKGROUND does nothing and returns TRUE.
Double Buffering is enabled.
Windows have the WS_CLIPSIBLINGS and WS_CLIPCHILDREN window styles.
In my resize event handler I immediately repaint the window.
I've tried:
Setting PFD_SUPPORT_COMPOSITION in the pixel format descriptor.
Not using a wxPaintDC in the paint handler and calling
::ValidateRect(hwnd, NULL) instead.
Handling WM_NCPAINT and excluding the client area
Disabling NC paint via the DWM API
Excluding the client area in the paint event
Calling glFlush and/or glFinish before and after the buffer swap.
Invalidating the window at every paint event (as a test!) - still
flickers!
Not using a shared GL context.
Disabling double buffering.
Writing to GL_FRONT_AND_BACK
Disabling DWM is not an option.
And as far as I am aware this is even a problem if you are using Direct3D instead on OpenGL, though I have not tested this as it represents a lot of work.
This is a longshot, but I just solved exactly this same problem myself.
The longshot part comes in because we're doing owner draw of the outline of a captionless group box that surrounds our OpenGL window (i.e., to make a nice little border), and that may not describe your case.
What we found caused the problem was this:
We had been using a RoundRect() call (with a HOLLOW_BRUSH) to draw the outline of the group box. Changing it to a MoveToEx() and LineTo() calls to ensure JUST the lines are drawn and nothing gets done inside the group box kept the GDI from trying to unexpectedly repaint the whole content of the control. It's possible there's a difference in invalidation logic (or we had a bug somehow in loading the intended hollow brush). We're still investigating.
-Noel
My app has only a single OpenGL window (the main window) but I ran into some nasty DWM tearing issues on window resize and I wonder if one of the solutions may work for you.
First of all, I found that during window resize there are at least two different bad guys who want to "help" you by modifying your client area before you have a chance to update the window yourself, creating flicker.
The first bad guy dates back to a XP/Vista/7 BitBlt inside the SetWindowPos() that Windows does internally during window resize, and can be eliminated with a trick involving intercepting WM_NCCALCSIZE or another trick involving intercepting WM_WINDOWPOSCHANGING.
In Windows 8/10 we still have that problem but we have a new bad guy, the Aero DWM.exe window manager, who will do his own different kind of BitBlt when he thinks you are "behind" updating the screen.
I suspect that the rubbish pixels you are seeing might actually be an intentional and very very poor attempt by DWM to fill in something "acceptable" while it waits for you to draw. I discovered that DWM extends the edge pixels of old client area data when it blits the new client area, which is insane.
Unfortunately, I don't know of any 100% solution to prevent DWM from doing this, but I do have a timing hack that greatly reduces the frequency of it.
For source code to the WM_NCCALCSIZE/WM_WINDOWPOSCHANGING hack as well as the DWM timing hack, please see:
How to smooth ugly jitter/flicker/jumping when resizing windows, especially dragging left/top border (Win 7-10; bg, bitblt and DWM)?
Hmm, maybe you have ran into the same issue: if you are using "new" MFC
it will create and application with Tabs and Window Spliter.
The splitter has some logic (I am guessing somewhere around transparent window and drawing XOR
lines for the split) that causes this behavior. Remove the splitter to confirm it resolve
your issue. If you need split functionality -- put in a different splitter.
Also Tabs allow docking and again splitting the windows that has the same issue -- remove/replace.
Good luck,
Igor
When I switch one of my monitor to fullscreen mode, sometimes the other monitors just become black and won't show anything. Did I do something wrong or it is just some bug?
I created a window, and then created a swapchain binded to that window. And I called the swapchain's SetFullScreenState with first parameter true, and second parameter the IDXGIOutput object of the monitor I wanted to switch fullscreen. Sometimes it works fine, but sometimes all the other monitors are lost (with only the fullscreened one showing things).
My graphics card is Radeon HD6750, and driver version is 12.3.
I found the MulitMon10 sample has the same problem, while some games don't. Or do Skyrim and The Tales of Monkey Island use D3D or OpenGL...?
This question is two years old. I just came across it.
I had a similar issue with DX11, sometimes happening in debug version, systematicaly in release version.
In my paradigm, the primary monitor hosts a console and an optional 'press buttons' GUI. The secondary monitor (one among available ones) is the fullscreen application window where 2D professional images are displayed and GPU transformed using 1D and 3D lookup tables.
Having the primary monitor going blank was a show stopper. All needed dialogs are childs of the console window (thus, opening on the primary monitor). The secondary monitor is a motion picture digital projector .... enough 'blabla'.
So, my solution was to create the swapchain in windowed mode while the targeted window was already in fullscreen mode.
Do not ask me why. It works for me. Here is a bit more:
First, my display window is set to fill the entire monitor surface ( no border, no everything).
Second, I create the swapchain for this window with “windowed = true”.
In facts, even if it looks fullscreen, it is windowed. With no border, it works the same as far as displaying/rendering 2D images is concerned. Feeding directly the backbuffer works too.
Then, and only then, you can switch the backbuffer to real administrative fullscreen. Since this operation is extremely brutal for the eyes, I tend to only do it when absolutely necessary. In effects, Win7 will reset the entire desktop (thus, all monitors, all windows) and create multiple light flashes.
When going real fullscreen after the backbuffer is created, I never experienced the desagrement of being stuck in the midle of a desktop reset (back to the original question).
To be complete, there is a difference between ‘Windowed fullscreen’ and ‘Real fullscreen’. Something you may use.
Windowed fullscreen: other windows/dialogs will overlap your 2D creation.
Real fullscreen: other windows/dialog should stay underneath (not visible, but there).
Toggling between the two modes upon need would be nice, except the desktop reset stress is an heavy penalty to live with.
I want to create my own tiny windowless GUI system, for that I am using GDI+. I cannot post code here because it got huge(c++) but bellow is the main steps I am following...
Create a bitmap of size equal to the application window.
For all mouse and keyboard events update the custom control states (eg. if mouse is currently held over a particular control e.t.c.)
For WM_PAINT event paint the background to offscreen bitmap and then paint all the updated controls on top of it and finally copy entire offscreen image to the front buffer via Graphics::DrawImage(..) call.
For WM_SIZE/WM_SIZING delete the previous offscreen bitmap and create another one with new window size.
Also there are some checks to prevent repeated drawing of controls i.e. controls are drawn only when it needs repainting in other words when the state of a control is changed only then it is painted e.t.c.
The system is working fine but only with one exception...when window is being resizing something sort of tearing effect appears. Now what I mean by tearing effect I shall try to explain ...
On the sizing edge/border there is a flickering gap as I drag the border.It is as if my DrawImage() function returns immediately and while one swap operation is half done another image drawing starts up.
Now you may think that it is common artifact that happens in many other application for the fact that resizing backbuffer is not always as fast as resizing window are but in other applications I noticed in other applications that although there is a leg between window size and client area size as window grows in size nothing flickers near the edge (its usually just white background that shows up as thin uniform strips along the border).
Also the dynamic controls which move with window resize acts jerky during sizing.
At first it seemed to me that using a constant fullscreen size offscreen surface could minimize the artifact but when I tried it results are not that satisfactory. I also tried to call Sleep() during sizing so that the flipping is done completely before another flip starts but strangely even that won't worked for me!
I have heard that GDI on vista is not hardware accelerated, could that might be the problem?
Also I wonder how frameworks such as Qt renders windowless GUI so smoothly, even if you size a complex Qt GUI window very fast negligibly little artifact appears. As far as I know Qt can use opengl for GUI rendering but that is second option.
If I use directx then real time resizing is even harder, opengl on the other hand seems to be nice for resizing without any problem but I will loose all the 2d drawing capability of GDI+.
If any of you have done anything like this before please guide me. Also if you have any pointer that I should consider for custom user interface design then provide me the links.
Thanks!
I always wished to design interfaces like windows media player 11 but can someone tell me that there is a straight forward solution for a c++ programmer (I want to know how rather than use some existing framework etc.)? Subclassing, owner drawing, custom drawing nothing seems to give you such level of control, I dont know a way to draw semitransparent control with common controls, so I think this question deserves some special attention . Thanks again.
Could it be a WM_ERASEBKGND message that's causing it?
see this question: GDI+ double buffering in C++
Also, if you need fast response from your GUI I would advise against GDI+.
There is this weird bug in my program that I'm trying to fix, but I'm really at a loss for what it could be. This part of my program has a dialog which shows previews of various items using MFC/GDI. When I scroll through different items, sometimes the preview image just disappears and goes blank. However, it:
Only happens on some machines
Apparently happens on both Windows 7 and XP
Doesn't happen on the same item every time
Item IS STILL THERE when one takes a screenshot, but it is blank when viewing it normally.
Seems to happen at random places throughout the code when I'm attempting to trace through it with breakpoints. It's not always in the same location that the screen goes from image to blank, which leads me to believe that it's not happening in the same thread as my main thread, even though that's really the only thread that's not blocked at that point. That means that it's happening in a windows thread or something, doesn't it?
I'm assuming it's a race condition of some sort, but the behaviour of the preview in screenshots, in particular, rather confuses me. Why would it be fine when taking a screenshot but be blank when viewing it on screen? Is there some mechanic of the "printscreen" that bypasses what's displyed or updated on the screen?
I realize that I haven't given much information and that people obviously can't help much, but if anyone could think of ANYTHING, it would be much appreciated :)
Thanks!
Another theory: GDI resource leak
If you forget to free your GDI objects, weird things start to happen - including unpainted areas.
Run taskmgr.exe and add the "GDI Objects" column.
Run your software and monitor the GDI object count. Does it stabilize?
If your GDI Object count does not stabilize, look in your relevant WM_PAINT handlers.
Here's an example of a GDI leak:
void CMyWnd::OnPaint()
{
CPaintDC dc(this);
dc.SelectObject(&font);
}
Selected GDI objects must always be deselected:
void CMyWnd::OnPaint()
{
CPaintDC dc(this);
CFont *pOldFont = dc.SelectObject(&font);
// Use font
dc.SelectObject(pOldFont);
}
When you record your screen, are you reading the desktop using GDI apis? In that case, any hardware-accelerated surface may become black (or possibly white). To test this, you can disable hardware acceleration for your graphics card. If your recorder starts working then you've found the culprit!
To record these non-GDI surfaces you probably need to read the surface using DirectX/OpenGL. I would start with this article: http://www.codeproject.com/KB/dialog/screencap.aspx
I've seen things like this and I was wondering if this was possible, say I run my application
and it will show the render on whatever is below it.
So basically, rendering on the screen without a window.
Possible or a lie?
Note: Want to do this on windows and in c++.
It is possible to use your application to draw on other application's windows. Once you have found the window you want, you have it's HWND, you can then use it just like it was your own window for the purposes of drawing. But since that window doesn't know you have done this, it will probably mess up whatever you have drawn on it when it tries to redraw itself.
There are some very complicated ways of getting around this, some of them involve using windows "hooks" to intercept drawing messages to that window so you know when it has redrawn so that you can do your redrawing as well.
Another option is to use clipping regions on a window. This can allow you to give your window an unusual shape, and have everything behind it still look correct.
There are also ways to take over drawing of the desktop background window, and you can actually run an application that draws animations and stuff on the desktop background (while the desktop is still usable). At least, this was possible up through XP, not sure if it has changed in Vista/Win7.
Unfortunately, all of these options are too very complex to go in depth without more information on what you are trying to do.
You can use GetDesktopWindow(), to get the HWND of the desktop. But as a previous answer says (SoapBox), be careful, you may mess up the desktop because the OS expects that it owns it.
I wrote an open source project a few years ago to achieve this on the desktop background. It's called Uberdash. If you follow the window hierarchy, the desktop is just a window in a sort of "background" container. Then there is a main container and a front container. The front container is how windows become full screen or "always on top." You may be able to use Aero composition to render a window with alpha in the front container, but you will need to pass events on to the lower windows. It won't be pretty.
Also, there's a technology in some video cards called overlays/underlays. You used to be able to render directly to an overlay. Your GPU would apply it directly, with no interference to main memory. So even if you took a screen capture, your overlay/underlay would not show up in the screen cap. Unfortunately MS banned that technology in Vista...