class `ParticleScene`

Keeps track of all active ParticleSystems in a particular scene and performs per-frame updates.

Public

Constructors

ParticleScene

ParticleScene()

Default constructor.

Call SetOwner() after construction.

Methods

~ParticleScene

~ParticleScene() noexcept

SetOwner

void SetOwner(const SPtr<SceneInstance> &scene)

Set the owning scene instance.

Must be called after construction.

Update

EvaluatedParticleData *Update(const EvaluatedAnimationData &animData)

Advances the simulation for all particle systems using the current frame time delta.

Outputs a set of data that can be used for rendering

& updating every active particle system.

Play

void Play(ecs::ParticleSimulation &simulation, const ParticleSystemSettings &settings)

Starts or resumes the particle system.

New particles will be emitted and existing particles will be evolved.

Pause

void Pause(ecs::ParticleSimulation &simulation)

Pauses the particle system.

New particles will stop being emitted and existing particle state will be frozen.

Stop

void Stop(ecs::ParticleSimulation &simulation)

Stops the particle system and resets it to initial state, clearing all particles.

CalculateBounds

AABox CalculateBounds(const ecs::ParticleSimulation &simulation) const

Calculate current particle bounds.

AllocateId

u32 AllocateId()

Allocates a unique particle system ID.

Used by the ParticleSystem component and ECS-only users.

staticCreate

static SPtr<ParticleScene> Create()

Creates a new empty particle scene.

Private

Methods

PreSimulate

void PreSimulate(const ParticleSystemState &state, u32 startIndex, u32 count, bool spacing, float spacingOffset)

Decrements particle lifetime, kills expired particles and executes evolvers that need to run before the simulation.

state: State describing the current state of the simulation.
startIndex: Index of the first particle to update.
count: Number of particles to update, starting from .
spacing: When false all particles will use the same time-step. If true the time-step will be divided by so particles are uniformly distributed over the time-step.
spacingOffset: Extra offset that controls the starting position of the first particle when calculating spacing. Should be in range [0, 1). 0 = beginning of the current time step, 1 = start of next particle.

Simulate

void Simulate(const ParticleSystemState &state, u32 startIndex, u32 count, bool spacing, float spacingOffset)

Simulates particle properties, advancing the simulation.

state: State describing the current state of the simulation.
startIndex: Index of the first particle to update.
count: Number of particles to update, starting from .
spacing: When false all particles will use the same time-step. If true the time-step will be divided by so particles are uniformly distributed over the time-step.
spacingOffset: Extra offset that controls the starting position of the first particle when calculating spacing. Should be in range [0, 1). 0 = beginning of the current time step, 1 = start of next particle.

PostSimulate

void PostSimulate(const ParticleSystemState &state, u32 startIndex, u32 count, bool spacing, float spacingOffset)

Executes evolvers that need to run after the simulation.

state: State describing the current state of the simulation.
startIndex: Index of the first particle to update.
count: Number of particles to update, starting from .
spacing: When false all particles will use the same time-step. If true the time-step will be divided by so particles are uniformly distributed over the time-step.
spacingOffset: Extra offset that controls the starting position of the first particle when calculating spacing. Should be in range [0, 1). 0 = beginning of the current time step, 1 = start of next particle.

AdvanceSimulation

void AdvanceSimulation(ecs::ParticleSimulation &simulation, const ecs::ParticleSystem &config, const ecs::WorldTransform &transform, float timeDelta, const EvaluatedAnimationData *animData)

Advances the simulation for a single particle system by the given time delta.

Handles emitting, evolving, and integrating all particles.

SortParticles

void SortParticles(const ParticleSet &set, ParticleSortMode sortMode, const Vector3 &viewPoint, u32 *indices)

Sorts the particles in the provided the .

Sorted particle indices are placed in the

array which is expected to be pre-allocated with enough space to hold an index for each particle in a set. is used as a reference point when using the Distance sort mode.

Fields

mOwner

WeakSPtr<SceneInstance> mOwner

m

Members * m

mNextId

u32 mNextId

mPaused

bool mPaused

mSimulationData

EvaluatedParticleData[2] mSimulationData

mReadBufferIdx

u32 mReadBufferIdx

mWriteBufferIdx

u32 mWriteBufferIdx

mMutex

Mutex mMutex

mSwapBuffers

bool mSwapBuffers