v1.4.4

source/core/StarNetElementSignal.hpp

@@ -0,0 +1,145 @@
+#ifndef STAR_NET_ELEMENT_SIGNAL_HPP
+#define STAR_NET_ELEMENT_SIGNAL_HPP
+
+#include "StarNetElement.hpp"
+
+namespace Star {
+
+// NetElement that sends signals during delta writes that can be received by
+// slaves.  It has no 'state', and nothing is sent during a store / load, and
+// it only keeps past signals for a maximum number of versions.  Thus, it is
+// not appropriate to use to send updates to long term states, only for event
+// like things that are not harmful if missed.
+template <typename Signal>
+class NetElementSignal : public NetElement {
+public:
+  NetElementSignal(size_t maxSignalQueue = 32);
+
+  void initNetVersion(NetElementVersion const* version = nullptr) override;
+
+  void netStore(DataStream& ds) const override;
+  void netLoad(DataStream& ds) override;
+
+  void enableNetInterpolation(float extrapolationHint = 0.0f) override;
+  void disableNetInterpolation() override;
+  void tickNetInterpolation(float dt) override;
+
+  bool writeNetDelta(DataStream& ds, uint64_t fromVersion) const override;
+  void readNetDelta(DataStream& ds, float interpolationTime = 0.0) override;
+
+  void send(Signal signal);
+  List<Signal> receive();
+
+private:
+  struct SignalEntry {
+    uint64_t version;
+    Signal signal;
+    bool received;
+  };
+
+  size_t m_maxSignalQueue;
+  NetElementVersion const* m_netVersion = nullptr;
+  bool m_netInterpolationEnabled = false;
+  Deque<SignalEntry> m_signals;
+  Deque<pair<float, Signal>> m_pendingSignals;
+};
+
+template <typename Signal>
+NetElementSignal<Signal>::NetElementSignal(size_t maxSignalQueue) {
+  m_maxSignalQueue = maxSignalQueue;
+}
+
+template <typename Signal>
+void NetElementSignal<Signal>::initNetVersion(NetElementVersion const* version) {
+  m_netVersion = version;
+  m_signals.clear();
+}
+
+template <typename Signal>
+void NetElementSignal<Signal>::netStore(DataStream&) const {}
+
+template <typename Signal>
+void NetElementSignal<Signal>::netLoad(DataStream&) {
+}
+
+template <typename Signal>
+void NetElementSignal<Signal>::enableNetInterpolation(float) {
+  m_netInterpolationEnabled = true;
+}
+
+template <typename Signal>
+void NetElementSignal<Signal>::disableNetInterpolation() {
+  m_netInterpolationEnabled = false;
+  for (auto& p : take(m_pendingSignals))
+    send(move(p.second));
+}
+
+template <typename Signal>
+void NetElementSignal<Signal>::tickNetInterpolation(float dt) {
+  for (auto& p : m_pendingSignals)
+    p.first -= dt;
+
+  while (!m_pendingSignals.empty() && m_pendingSignals.first().first <= 0.0f)
+    send(m_pendingSignals.takeFirst().second);
+}
+
+template <typename Signal>
+bool NetElementSignal<Signal>::writeNetDelta(DataStream& ds, uint64_t fromVersion) const {
+  size_t numToWrite = 0;
+  for (auto const& p : m_signals) {
+    if (p.version >= fromVersion)
+      ++numToWrite;
+  }
+  if (numToWrite == 0)
+    return false;
+
+  ds.writeVlqU(numToWrite);
+
+  for (auto const& p : m_signals) {
+    if (p.version >= fromVersion)
+      ds.write(p.signal);
+  }
+
+  return true;
+}
+
+template <typename Signal>
+void NetElementSignal<Signal>::readNetDelta(DataStream& ds, float interpolationTime) {
+  size_t numToRead = ds.readVlqU();
+  for (size_t i = 0; i < numToRead; ++i) {
+    Signal s;
+    ds.read(s);
+    if (m_netInterpolationEnabled && interpolationTime > 0.0f) {
+      if (!m_pendingSignals.empty() && m_pendingSignals.last().first > interpolationTime) {
+        for (auto& p : take(m_pendingSignals))
+          send(move(p.second));
+      }
+      m_pendingSignals.append({interpolationTime, move(s)});
+    } else {
+      send(move(s));
+    }
+  }
+}
+
+template <typename Signal>
+void NetElementSignal<Signal>::send(Signal signal) {
+  m_signals.append({m_netVersion ? m_netVersion->current() : 0, signal, false});
+  while (m_signals.size() > m_maxSignalQueue)
+    m_signals.removeFirst();
+}
+
+template <typename Signal>
+List<Signal> NetElementSignal<Signal>::receive() {
+  List<Signal> received;
+  for (auto& p : m_signals) {
+    if (!p.received) {
+      received.append(p.signal);
+      p.received = true;
+    }
+  }
+  return received;
+}
+
+}
+
+#endif