Method ProcessInputSources

Plugins/NativeXr/Source/NativeXr.cpp:1340–1420

            }

            void ProcessInputSources(const xr::System::Session::Frame& frame, Napi::Env env)
            {
                // Figure out the new state.
                std::set<xr::System::Session::Frame::InputSource::Identifier> added{};
                std::set<xr::System::Session::Frame::InputSource::Identifier> current{};
                std::set<xr::System::Session::Frame::InputSource::Identifier> removed{};
                for (auto& inputSource : frame.InputSources)
                {
                    if (!inputSource.TrackedThisFrame)
                    {
                        continue;
                    }

                    current.insert(inputSource.ID);

                    auto found = m_idToInputSource.find(inputSource.ID);
                    if (found == m_idToInputSource.end())
                    {
                        // Create the new input source, which will have the correct spaces associated with it.
                        m_idToInputSource.insert({inputSource.ID, CreateXRInputSource(inputSource, env)});

                        added.insert(inputSource.ID);
                    }
                    else
                    {
                        // Ensure the correct spaces are associated with the existing input source.
                        auto val = found->second.Value();
                        SetXRInputSourceSpaces(val, inputSource);
                    }
                }
                for (const auto& [id, ref] : m_idToInputSource)
                {
                    if (current.find(id) == current.end())
                    {
                        // Do not update space association since said spaces no longer exist.
                        removed.insert(id);
                    }
                }

                // Only need to do more if there's been a change. Note that this block of code assumes
                // that ALL known input sources -- including ones added AND REMOVED this frame -- are
                // currently up-to-date and accessible though m_idToInputSource.
                if (added.size() > 0 || removed.size() > 0)
                {
                    // Update the input sources array.
                    auto jsCurrent = Napi::Array::New(env);
                    for (const auto id : current)
                    {
                        jsCurrent.Set(jsCurrent.Length(), m_idToInputSource[id].Value());
                    }
                    m_jsInputSources = Napi::Persistent(jsCurrent);

                    // Create and send the sources changed event.
                    Napi::Array jsAdded = Napi::Array::New(env);
                    for (const auto id : added)
                    {
                        jsAdded.Set(jsAdded.Length(), m_idToInputSource[id].Value());
                    }