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I can't find any documentation on the ICompositor interace, anywhere.
Are there docs out there?
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(262.40000000000003, 13%, 35%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EDR%3C/text%3E%3C/svg%3E)
This isn't a simple topic. It would be better if you explained what you want to do this time.
It is winrt::Windows::UI::Composition::ICompositor => https://learn.microsoft.com/en-us/uwp/api/windows.ui.composition.compositor?view=winrt-26100
Thank you.
I was looking at that a moment ago, and not finding anything on ICompositor.
Is the documentation limited in some way, or is ICompositor no longer used?
This is a complicated topic. But Windows.UI.Composition.ICompositor is used, but it is hidden away. If you use the projected Windows.UI.Composition.Compositor then the projection will automatically use the correct interfaces as required.
You should use the documentation for Windows.UI.Composition.Compositor as the documentation for all of the interfaces of Compositor combined. It is recommended to use a projection such as C++/WinRT and use winrt::Windows::UI::Composition::Compositor. If you are in a situation where you must use Windows.UI.Composition.ICompositor, then there are ways to get access to it, but care has to be used.
Interesting.
I am experimenting with using a Composition Swap Chain with Direct Composition, and was following the examples on this page.
I ran into a roadblock when I used the Example 3—Binding a presentation surface to a Windows.UI.Composition surface brush, since I got an error, as I expected, since the Compositor was not initialize with anything.
So, I went in search for the interface that creates the Compositor, and came up empty.
I changed ICompositor to Compositor, and to my surprise I got no error.
If you don't mind, can you explain why that is the case please, and are there other interfaces, which I may run into, that operate this way?
Thanks.
If you don't mind, can you explain why that is the case please, and are there other interfaces, which I may run into, that operate this way?
Any Windows Runtime (WinRT) API will have this. But this is also not something that is easy to explain in a forum reply.
One big thing to clear up though is that in the sample that is being referred to, the ICompositor doesn't refer to winrt::Windows::UI::Composition::ICompositor, but ABI::Windows::UI::Composition::ICompositor.
As to what is going on here, the WinRT API was designed to be class based, but also available to multiple programming languages. But since different languages do different things, Microsoft used an existing technology that these other languages could use, and it is COM. The existing technology providing the building blocks that languages could then use to provide the class based library. These building blocks, known as the ABI, was available to C/C++ easily.
That sample is using the building blocks to do things, and not the C++ projection, which is the class based layout using the building blocks under the surface. This was why I asked what you were doing, since how you handle things depends on why you wanted ICompositor.