I want to build and editor, similar to many 3d editors out there, that has an opengl viewport somewhere in the window, and the rest of the window contains Windows controls. How do I do that? So far I managed to create a window that opengl renders to all of its area.
Although it is better to avoid rendering to the OpenGL window except via OpenGL, the controls are child windows in their own right, so there should be no problem simply rendering to part of the parent window (glViewPort can help with that). Windows will take care of drawing the controls "on top of" the parent window. Alternatively, you can create a child window of your own and attach the OpenGL context to the child window. Then you can render to the whole of the child window.
Let's say we have two screen scenario and a NSWindow,
positioned at the edge of screen 1.
A part of that of that window is also shown on screen 2.
What I would like to achieve, is to draw the window only on screen 1 and to not show the rest on screen 2.
The reason for that is that's some kind of a specially behaving mini window, not a usual one.
Is it possible to assign a certain NSScreen to draw the window on, only?
Two very different approaches:
Use Mavericks: What you looking for sounds like the behaviour of Mavericks' "screens have separate spaces" mode. In this mode a window is never drawn on two screens except during drag operations, at other times the window is draw on one screen with any areas protruding onto adjacent screens clipped. So if you can restrict use to 10.9 this may save you some work.
Borderless Windows: You can create a borderless non-opaque NSWindow, just set the appropriate flags. This is how applications create non-square windows, the visible area of the window is now entirely up to you. Now just clip your drawing to the area on one screen using the standard clipping support. You won't have a standard title bar or controls, unless you emulate them yourself, so you have to implement drag yourself etc. You say you have "some kind of a specially behaving mini window, not a usual one" so that may not be an issue.
Not that I've heard of.
What you could do though is restricting the position of the window e.g. via a NSWindowDelegate and windowDidMove: to listen to position changes and reposition the window appropriately.
I have an OpenGL view on the Mac. I want to put a NSTextField in front of it, but even if I put it in front, it is obscured by the view.
There is a very simple test case. Create a new project in XCode (I'm using 4.0.2) and a window. Add an OpenGL view. Now add a text field and set it so that half of it overlaps the OpenGL view. Run the program. The whole field shows, but when you type the text, only half of it shows, no matter how you arrange the fields front to back.
An NSOpenGLView doesn't actually draw within the window, it draws in a surface that is above or below the window, above by default. If you want a control in front of the OpenGL surface, you must make the surface below the window, using the NSOpenGLContext parameter NSOpenGLCPSurfaceOrder. But then you must cut a transparent rectangle in the window to be able to see the OpenGL surface.
Edit to add: Alternately, you could make a transparent overlay or child window that is above the OpenGL surface as well as the main window, and put the control there. Not sure which way would be easier.
I want to use a free form shape (e.g. A partially transparent image) as a window backgound without the standard close and maximise buttons. Like the widgets do. Is that possible in OSX? I could not find any info on that or an app that uses this.
Thanks
Yes. You can do this by subclassing NSWindow to make it borderless and transparent. You'll also subclass NSView to draw the visible custom shape, then use an instance of this view as the window's content view. The result will be a window whose only visible parts will be the shape your content view draws.
Here's a good article with an example.
Looking at a Windows tooltips class hint window, i see that it draws its drop-shadow outside the hint window's actual rectangle.
Using SpyXX - i can get the tooltip's window rect, and class styles:
Rectangle: (440, 229)-(544, 249), 104x20
Restored Rect: (440, 229)-(544, 249), 104x20
Client Rect: (0, 0)-(104, 20), 104x20
You'll notice that the drop shadow you see is physically outside the window that's being drawn. How can i draw a shadow outside around my window, while being outside my window?
Note: The shadow is not drawn using the standard CS_DROPSHADOW class style. i've confirmed this experimentally, and can also see the class style's for the window in SpyXX; it does not use CS_DROPSHADOW:
Windows Styles: 94000001
WS_POPUP 80000000
WS_VISIBLE 10000000
WS_CLIPSIBLINGS 4000000
TTS_ALWAYSTIP 1
Extended Styles: 00080088
WS_EX_LAYERED 80000
WS_EX_TOOLWIN 80
WS_EX_TOPMOST 8
So how can i draw outside my window?
Note: Trying to draw on the desktop DC is out. From Greg Schechter's Redirecting GDI, DirectX, and WPF applications:
Drawing To and Reading From the Screen
-- Baaaad!
Lastly, since we're on the redirection
topic, one particularly dangerous
practice is writing to the screen,
either through the use of GetDC(NULL)
and writing to that, or attempting to
do XOR rubber-band lines, etc. There
are two big reasons that writing to
the screen is bad:
It's expensive... writing to the
screen itself isn't expensive, but it
is almost always accompanied by
reading from the screen because one
typically does read-modify-write
operations like XOR when writing to
the screen. Reading from the video
memory surface is very expensive,
requires synchronization with the DWM,
and stalls the entire GPU pipe, as
well as the DWM application pipe.
It's unpredictable... if you somehow
manage to get to the actual primary
and write to it, there can be no
predictability as to how long what you
wrote to the primary will remain on
screen. Since the UCE doesn't know
about it, it may get cleared in the
next frame refresh, or it may persist
for a very long time, depending on
what else needs to be updated on the
screen. (We really don't allow direct
writing to the primary anyhow, for
that very reason... if you try to
access the DirectDraw primary, for
instance, the DWM will turn off until
the accessing application exits)
You can't draw outside your window in the manner you describe.
If you right click your desktop then go to properties/appearance/effects and uncheck 'Show shadows under menus' ... you will no longer have the shadow.
Bottom line is that this is a product of the window manager not your program.
Q: How do you draw outside of one window? A: Draw inside another window!
First thing to note is that the tooltip class actually does use the CS_DROPSHADOW style - but note that this is a class style, not a window style, so you have to look at the Class tab in the Spy++ properties dialog to find it. You'll see that the tooltips_class32 windows does indeed have this - and a few others.
But that just leads to the next question - how does that work? Well, it seems that Windows implements this by creating a helper HWND to draw the shadow - presumably it's creating another popup window the same size and shape as the one it's shadowing, filling it with gray, placing it directly underneath the main window, and setting it as a WS_EX_LAYERED window so that the shadow can be transparent and fade out around the edges using alpha-blending. And there's nothing to stop you from using the same or similar techniques yourself if you want to add a different type of shadow effect to one of your own windows.
So, long story short: if you want to draw outside of your own window, create a helper transparent window in the general area that you want to draw on, and draw on that helper window instead.
--
Now, if you try to find one of these helper shadow windows in Spy++, you won't find much. Unlike the tooltip_class32 windows, which are long-lived and just hide/show themselves as needed, these shadow windows are a more elusive creature: they are only created for as long as needed, so you'd have to refresh Spy++ while there's a tooltip or popup menu or other window using the shadow present - and that's tricky, since most tooltips and menus will disappear as soon as you move the mouse to switch to Spy++. But it turns out that the tooltips on Spy++'s own toolbar will stick around: so start Spy++, hover over an item in the toolbar, and hit F5 to refresh the HWND tree while the tooltip and shadow are present. Now scroll down, and you should see the third and fourth visible HWNDs in the tree are the tooltip itself, and right after that, a SysShadow window. Unfortunately, since the tooltip and shadow have by now disappeared, if you attempt to get the properties dialog for that HWND, you'll get a get a blank property dialog with an 'Invalid Window' message. If you really want to poke around and see how that SysShadow works, what styles it itself uses and so on, you could create a target app with a long-lived popup that uses CS_DROPSHADOW that you can then explore in Spy++ at leisure.
(Finally, note that these shadows are a completely different thing than the shadows that you see when one app window is on top of another above another since Vista: this type of shadow is part of Aero Glass mode, and handled by the same Desktop Composition Manager that adds the glass titlebar effect, and it doesn't use or need helper windows to implement the shadows.)
I wouldn't be surprised if that shadow is intimately tied to the window manager itself; it is after all the window manager who decides what window gets to paint which parts of itself and when it can do it. I don't see it as rocket science to paint that shadow if control over all that is gained, which the window manager has.