LowLatencyInput

topic	languages	products
sample	cpp cppcx	windows windows-uwp

Low latency input sample

Shows how to handle input on a dedicated input thread to achieve lowest input latency.

Note: This sample is part of a large collection of UWP feature samples. If you are unfamiliar with Git and GitHub, you can download the entire collection as a ZIP file, but be sure to unzip everything to access shared dependencies. For more info on working with the ZIP file, the samples collection, and GitHub, see Get the UWP samples from GitHub. For more samples, see the Samples portal on the Windows Dev Center.

Specifically, this sample shows:

1. Setting up two rectangles, one rendered using DirectX and one using XAML
2. Using a SwapChainPanel embedded in a XAML app to render and draw DirectX content
3. Achieving lowest input latency by setting up a dedicated input thread using swapChainPanel->CreateCoreIndependentInputSource(CoreInputDeviceTypes::Mouse | CoreInputDeviceTypes::Touch | CoreInputDeviceTypes::Pen);
4. Achieving lowest output latency using Waitable Back Buffers
5. Artificially blocking the UI thread to show the XAML rect rendering choppy and the DirectX rect rendering smooth and unaffected

Note The Windows universal samples require Visual Studio 2017 to build and Windows 10 to execute.

To obtain information about Windows 10 development, go to the Windows Dev Center

To obtain information about Microsoft Visual Studio and the tools for developing Windows apps, go to Visual Studio

Related topics

Reference

Reduce latency with DXGI 1.3 swap chains
DirectX and XAML
Creating an dedicated input thread

System requirements

Client: Windows 10

Server: Windows Server 2016 Technical Preview

Phone: Windows 10

Build the sample

1. If you download the samples ZIP, be sure to unzip the entire archive, not just the folder with the sample you want to build.
2. Start Microsoft Visual Studio 2017 and select File > Open > Project/Solution.
3. Starting in the folder where you unzipped the samples, go to the Samples subfolder, then the subfolder for this specific sample, then the subfolder for your preferred language (C++, C#, or JavaScript). Double-click the Visual Studio Solution (.sln) file.
4. Press Ctrl+Shift+B, or select Build > Build Solution.

Run the sample

The next steps depend on whether you just want to deploy the sample or you want to both deploy and run it.

Deploying the sample

• Select Build > Deploy Solution.

Deploying and running the sample

• To debug the sample and then run it, press F5 or select Debug > Start Debugging. To run the sample without debugging, press Ctrl+F5 or selectDebug > Start Without Debugging.