TobiiPro LSL App Installation

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TobiiPro Installation

This document provides detailed instructions for building the LabStreamingLayer TobiiPro application from source for interfacing with Tobii eye trackers.

https://labstreaminglayer.readthedocs.io/dev/app_build.html https://labstreaminglayer.readthedocs.io/dev/build_env.html

Clone repository

Download / Install Dependencies:

The TobiiPro LSL app has three main dependencies:

  • TobiiPro C SDK
  • LSL
  • Qt5

TobiiPro C SDK

The TobiiPro C SDK is what the app uses to interface with the device. The cmake build looks for this in a specific location within the source code.

  • Download the TobiiPro C SDK
  • Extract the SDK and copy the ‘/64’ directory (which has the /include and /lib folders) into the App-TobiiPro directory and rename to ‘tobii’

LSL

  • Download latest release of LabStreamingLayer
  • Extract it to a known location (this can be configured with cmake).

Qt

The TobiiPro app currently requires Qt5. This can be installed using a package manager, such as homebrew, or manually using the Qt Installer. To use the installer:

  • Download the Qt Installer (for Open Source projects).
  • Create an account (login.qt.io); this is required during installation.
  • Run the Qt installer and do a Custom Installation to install Qt5 (currently at 5.15.2) prebuilt components for your system. The installation location can be configured with cmake.

Install Developer Tools

You will need a C / C++ compiler for your system, as well as the cmake build system.

  • C/C++ compiler
    • Mac: XCode developer tools
    • Windows: Visual Studio
  • cmake
    • usually installed with C tooling, but can be downloaded and installed separately
  • Visual Studio Code is recommended for configuring and running cmake. The instructions provided are cross-platform. In addition to the IDE, you should install the C/C++ extension from Microsoft, which includes the ms-vscode.cmake-tools extension.

Configuring and Running CMake using VS Code

Building an executable with CMake is a two step process:

  1. Running CMake to Configure the project and generate a native build system.
  2. Call the generated build system to actually compile/link the project.

CMake Configuration

The CMake Configuration step must run prior to generating the build. For the Configuration step, you will need to instruct cmake which compiler (kit) to use, what kind of build to generate (Release or Debug), and where it should look for dependencies.

Open the Project in VS Code

Open the TobiiPro source code with Visual Studio Code. Note that the various CMake commands may be automatically run by VS Code and any errors will be captured in the Output section.

Select a compiler

Run the CMake: Select Kit command to select a compiler if one has not already been selected. This will present a pulldown list of options. Note that this command may be auto-run when you open the project in VS Code. If there are no items in the list, you may need to install a C/C++ compiler (see above).

Select a Variant

Run the CMake: Select Variant command and set this to ‘Release’. By default this is set to ‘Debug’.

Add dependency locations

Cmake needs to know where to look for the installed dependencies used in this project. There are many ways to provide cmake with these paths but the simplest is to point it to the <project>Config.cmake file for each dependency.

In the VS Code Settings for the current Workspace, configure the cmake.configureArgs with the parameters:

  • -DLSL_DIR=<path to LSL>/lib/cmake/LSL
  • -DQt5_DIR=<path to Qt>/lib/cmake/Qt5

These are passed as command line arguments so the -D prefix is required. The LSL_DIR argument should be the path to the directory with the LSLConfig.cmake file, and the Qt5_DIR should be the path to the Qt5Config.make file.

Alternatively, these can be provided by using a settings.json file in the .vscode directory with the contents:

{
    "cmake.configureArgs": [
        "-DLSL_DIR=<path_to_LSL>/lib/cmake/LSL",
        "-DQt5_DIR<path>/5.15.2/clang_64/lib/cmake/Qt5"
    ]
}

See also:

Add Support for Compiling C

The LSL cmake file executes C code to determine the system architecture. Without modification, attempting to run cmake will result in an error that the C language is not enabled. There are two ways to resolve this:

  1. [preferred method] Add enable_language(C) in the liblsl LSLCMake.cmake (immediately before the try_compile). See github issues.

  2. Modify the TobiiPro CMakeLists.txt file to include support for compiling C as well as C++ code.

Change:

project(TobiiPro
	LANGUAGES CXX
	VERSION 1.13.0)

To:

project(TobiiPro
	LANGUAGES C CXX
	VERSION 1.13.0)

Run CMake Configure

The CMake: Configure command generates the build files in the project’s build folder. These files will be written to the /build folder (unless it is configured differently).

The Output browser will show the command issued and will provide feedback (for missing dependencies, etc).

CMake Build

Run the CMake: Build command to build the final executable. This will be located in the /build directory and called TobiiPro.

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