Code/EnginePlugins/ParticlePlugin/Emitter/ParticleEmitter_Distance.h - dev - redgpu/ezEngine

Code/EnginePlugins/ParticlePlugin/Emitter/ParticleEmitter_Distance.h

54 строки2 KB

Jan Krassnigg

Added Expression Particle Behavior (#1884)

29 мар 2026, 23:32

29 мар 2026, 23:32071fa9d

#pragma once

#include <Foundation/Types/VarianceTypes.h>
#include <ParticlePlugin/Emitter/ParticleEmitter.h>

/// Emitter that spawns particles based on distance traveled
///
/// Spawns particles when the effect moves a certain distance from the last spawn position.
/// Useful for creating trails or footstep effects.
class EZ_PARTICLEPLUGIN_DLL ezParticleEmitterFactory_Distance final : public ezParticleEmitterFactory
{
  EZ_ADD_DYNAMIC_REFLECTION(ezParticleEmitterFactory_Distance, ezParticleEmitterFactory);

public:
  ezParticleEmitterFactory_Distance();

  virtual const ezRTTI* GetEmitterType() const override;
  virtual void CopyEmitterProperties(ezParticleEmitter* pEmitter, bool bFirstTime) const override;
  virtual void QueryMaxParticleCount(ezUInt32& out_uiMaxParticlesAbs, ezUInt32& out_uiMaxParticlesPerSecond) const override;

  virtual void Save(ezStreamWriter& inout_stream) const override;
  virtual void Load(ezStreamReader& inout_stream, const ezParticleEffectDescriptor& ownerEffectDescriptor, const ezParticleSystemDescriptor& ownerSystemDescriptor) override;

public:
  float m_fDistanceThreshold = 0.1f;    ///< Distance that must be traveled before spawning
  ezUInt32 m_uiSpawnCountMin = 1;       ///< Minimum particles per spawn
  ezUInt32 m_uiSpawnCountRange = 0;     ///< Random range added to spawn count
  ezString m_sSpawnCountScaleParameter; ///< Optional parameter to scale spawn count
};


class EZ_PARTICLEPLUGIN_DLL ezParticleEmitter_Distance final : public ezParticleEmitter
{
  EZ_ADD_DYNAMIC_REFLECTION(ezParticleEmitter_Distance, ezParticleEmitter);

public:
  float m_fDistanceThresholdSQR;
  ezUInt32 m_uiSpawnCountMin;
  ezUInt32 m_uiSpawnCountRange;
  ezTempHashedString m_sSpawnCountScaleParameter;

  virtual void CreateRequiredStreams() override;

protected:
  virtual bool IsContinuous() const override;
  virtual void OnFinalize() override;
  virtual void InitializeElements(ezUInt64 uiStartIndex, ezUInt64 uiNumElements) override;

  virtual ezParticleEmitterState IsFinished() override;
  virtual ezUInt32 ComputeSpawnCount(const ezTime& tDiff) override;

  bool m_bFirstUpdate = true;
  ezVec3 m_vLastSpawnPosition;
};