v1.4.4

source/core/StarNetElement.hpp

@@ -0,0 +1,62 @@
+#ifndef STAR_NET_ELEMENT_HPP
+#define STAR_NET_ELEMENT_HPP
+
+#include "StarDataStream.hpp"
+
+namespace Star {
+
+// Monotonically increasing NetElementVersion shared between all NetElements in
+// a network.
+class NetElementVersion {
+public:
+  uint64_t current() const;
+  void increment();
+
+private:
+  uint64_t m_version = 0;
+};
+
+// Primary interface for the composable network synchronizable element system.
+class NetElement {
+public:
+  virtual ~NetElement() = default;
+
+  // A network of NetElements will have a shared monotinically increasing
+  // NetElementVersion.  When elements are updated, they will mark the version
+  // number at the time they are updated so that a delta can be constructed
+  // that contains only changes since any past version.
+  virtual void initNetVersion(NetElementVersion const* version = nullptr) = 0;
+
+  // Full store / load of the entire element.
+  virtual void netStore(DataStream& ds) const = 0;
+  virtual void netLoad(DataStream& ds) = 0;
+
+  // Enables interpolation mode.  If interpolation mode is enabled, then
+  // NetElements will delay presenting incoming delta data for the
+  // 'interpolationTime' parameter given in readNetDelta, and smooth between
+  // received values.  When interpolation is enabled, tickNetInterpolation must
+  // be periodically called to smooth values forward in time.  If
+  // extrapolationHint is given, this may be used as a hint for the amount of
+  // time to extrapolate forward if no deltas are received.
+  virtual void enableNetInterpolation(float extrapolationHint = 0.0f);
+  virtual void disableNetInterpolation();
+  virtual void tickNetInterpolation(float dt);
+
+  // Write all the state changes that have happened since (and including)
+  // fromVersion.  The normal way to use this would be to call writeDelta with
+  // the version at the time of the *last* call to writeDelta, + 1.  If
+  // fromVersion is 0, this will always write the full state.  Should return
+  // true if a delta was needed and was written to DataStream, false otherwise.
+  virtual bool writeNetDelta(DataStream& ds, uint64_t fromVersion) const = 0;
+  // Read a delta written by writeNetDelta.  'interpolationTime' is the time in
+  // the future that data from this delta should be delayed and smoothed into,
+  // if interpolation is enabled.
+  virtual void readNetDelta(DataStream& ds, float interpolationTime = 0.0) = 0;
+  // When extrapolating, it is important to notify when a delta WOULD have been
+  // received even if no deltas are produced, so no extrapolation takes place.
+  virtual void blankNetDelta(float interpolationTime);
+};
+
+}
+
+#endif