tweak(particlesys): Decouple Particles render update from logic step

Core/GameEngine/Include/Common/GameDefines.h

@@ -87,6 +87,10 @@
 #define PRESERVE_RETAIL_SCRIPTED_CAMERA (1) // Retain scripted camera behavior present in retail Generals 1.08 and Zero Hour 1.04
 #endif
 
+#ifndef PRESERVE_RETAIL_PARTICLES
+#define PRESERVE_RETAIL_PARTICLES (1) // Preserve original look of particles present in retail Generals 1.08 and Zero Hour 1.04
+#endif
+
 #ifndef RETAIL_COMPATIBLE_CRC
 #define RETAIL_COMPATIBLE_CRC (1) // Game is expected to be CRC compatible with retail Generals 1.08, Zero Hour 1.04
 #endif

Core/GameEngine/Include/GameClient/ParticleSys.h

@@ -178,8 +178,10 @@ class Particle : public MemoryPoolObject,
 
 	Particle( ParticleSystem *system, const ParticleInfo *data );
 
-	Bool update();												///< update this particle's behavior - return false if dead
-	void doWindMotion();									///< do wind motion (if present) from particle system
+	Bool update(); ///< update this particle's behavior - return false if dead
+
+	void draw( Real timeScale ); ///< render update
+	void doWindMotion( Real timeScale ); ///< do wind motion (if present) from particle system
 
 	void applyForce( const Coord3D *force );		///< add the given acceleration
 
@@ -226,7 +228,6 @@ class Particle : public MemoryPoolObject,
 	// most of the particle data is derived from ParticleInfo
 
 	Coord3D						m_accel;														///< current acceleration
-	Coord3D						m_lastPos;													///< previous position
 	UnsignedInt				m_lifetimeLeft;									///< lifetime remaining, if zero -> destroy
 	UnsignedInt				m_createTimestamp;							///< frame this particle was created
 
@@ -577,7 +578,9 @@ class ParticleSystem : public MemoryPoolObject,
 	void attachToObject( const Object *obj );									///< attach this particle system to an Object
 
 	virtual Bool update( Int localPlayerIndex );								///< update this particle system, return false if dead
-	void updateWindMotion();							///< update wind motion
+
+	void draw( Real timeScale ); ///< render update
+	void updateWindMotion( Real timeScale ); ///< update wind motion
 
 	void setControlParticle( Particle *p );			///< set control particle
 
@@ -661,6 +664,12 @@ class ParticleSystem : public MemoryPoolObject,
 
 protected:
 
+	struct VisibilityState
+	{
+		VisibilityState() : isShrouded(false) {}
+		Bool isShrouded;
+	};
+
 	// snapshot methods
 	virtual void crc( Xfer *xfer ) override;
 	virtual void xfer( Xfer *xfer ) override;
@@ -670,6 +679,11 @@ class ParticleSystem : public MemoryPoolObject,
 																		ParticlePriorityType priority,
 																		Bool forceCreate = FALSE );	///< factory method for particles
 
+	void updateTransform(bool logicUpdate);
+	void updateParentTransform(const Matrix3D &parentXfrm);
+	void updateLocalTransform();
+
+	VisibilityState updateVisibility( Int localPlayerIndex );
 
 	const ParticleInfo *generateParticleInfo( Int particleNum, Int particleCount );	///< generate a new, random set of ParticleInfo
 	const Coord3D *computeParticlePosition();		///< compute a position based on emission properties
@@ -704,8 +718,10 @@ class ParticleSystem : public MemoryPoolObject,
 	Real							m_delayCoeff;										///< scalar value multiplied by burst delay
 	Real							m_sizeCoeff;										///< scalar value multiplied by initial size
 
-	Coord3D						m_pos;													///< this is the position to emit at.
-	Coord3D						m_lastPos;											///< this is the previous position we emitted at.
+	Coord3D						m_logicalPos;										///< this is the current logic position to emit at.
+																										///< Can be different from the actual emitter transform
+																										///< if the render update is faster than the logic step.
+	Coord3D						m_lastLogicalPos;								///< this is the previous logic position we emitted at.
 
 	ParticleSystem *	m_slaveSystem;									///< if non-null, another system this one has control of
 	ParticleSystemID	m_slaveSystemID;								///< id of slave system (if present)
@@ -735,6 +751,9 @@ class ParticleSystem : public MemoryPoolObject,
 /**
  * The particle system manager, responsible for maintaining all ParticleSystems
  */
+// TheSuperHacker @tweak The particle render update is now decoupled from the logic step.
+// The lifetime management remains coupled to the logic step.
+//
 class ParticleSystemManager : public SubsystemInterface,
 															public Snapshot
 {
@@ -751,7 +770,8 @@ class ParticleSystemManager : public SubsystemInterface,
 
 	virtual void init() override;									///< initialize the manager
 	virtual void reset() override;									///< reset the manager and all particle systems
-	virtual void update() override;								///< update all particle systems
+	virtual void update() override;								///< logic update for all particle systems
+	virtual void draw() override;									///< render update for all particle systems
 
 	virtual Bool isDummy() const { return false; }
 
@@ -832,7 +852,6 @@ class ParticleSystemManager : public SubsystemInterface,
 	UnsignedInt m_fieldParticleCount; ///< this does not need to be xfered, since it is evaluated every frame
 	UnsignedInt m_particleSystemCount;
 	Int m_onScreenParticleCount;                ///< number of particles displayed on screen per frame
-	UnsignedInt m_lastLogicFrameUpdate;
 	Int m_localPlayerIndex;	///<used to tell particle systems which particles can be skipped due to player shroud status
 
 private:
@@ -859,6 +878,7 @@ class ParticleSystemManagerDummy : public ParticleSystemManager
 	virtual void reset() override {}
 #endif
 	virtual void update() override {}
+	virtual void draw() override {}
 
 	virtual Bool isDummy() const override { return true; }