Struct ParticleParams 

#[repr(C)]
pub struct ParticleParams {

    pub position: [f32; 3],
    pub spread_cos: f32,
    pub direction: [f32; 3],
    pub speed_min: f32,
    pub gravity: [f32; 3],
    pub speed_max: f32,
    pub color_start: [f32; 4],
    pub color_end: [f32; 4],
    pub lifetime_min: f32,
    pub lifetime_max: f32,
    pub size_start: f32,
    pub size_end: f32,
    pub dt: f32,
    pub spawn_budget: u32,
    pub random_seed: u32,
    pub max_particles: u32,
}

Per-frame uniform consumed by the particle compute + render kernels. Carries the resolved emitter tunables (position, direction, gravity, …) plus the dynamic per-frame inputs the compute kernel needs to age + integrate + respawn the pool. Pushed at compute buffer(2) and vertex buffer(1) of the Metal particle passes, so the layout must stay in sync with ParticleParams in shaders/particle_types.slang. 144 bytes.

Fields

position: [f32; 3]

World-space spawn origin. packed_float3 in MSL: alignment 4, with spread_cos packed into the trailing float slot of the float4.

spread_cos: f32

Cosine of the emission cone’s half-angle. 1.0 = straight jet, -1.0 = full sphere.

direction: [f32; 3]

Unit-length mean emission direction.

speed_min: f32

Lower bound of the initial speed range, in units per second.

gravity: [f32; 3]

Constant per-frame acceleration applied to each particle.

speed_max: f32

Upper bound of the initial speed range, in units per second.

color_start: [f32; 4]

Linear-space RGBA at age = 0.

color_end: [f32; 4]

Linear-space RGBA at age = lifetime.

lifetime_min: f32

Lower bound of the particle lifetime range, in seconds.

lifetime_max: f32

Upper bound of the particle lifetime range, in seconds.

size_start: f32

Quad size at age = 0.

size_end: f32

Quad size at age = lifetime.

dt: f32

Frame delta time (seconds). Drives the age + integration step.

spawn_budget: u32

Integer count of new particles the compute kernel may emit this frame. Carried atomically inside the kernel so threads racing for spawn slots only succeed up to this many times.

random_seed: u32

Per-frame seed mixed with the thread id by the kernel’s cheap RNG.

max_particles: u32

Pool size in slots; the kernel returns early past it.

Trait Implementations

impl Clone for ParticleParams

fn clone(&self) -> ParticleParams

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ParticleParams

impl Debug for ParticleParams

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl NoUninit for ParticleParams