Struct Particle 

pub struct Particle {
    pub x: i16,
    pub y: i16,
    pub x_frac: u8,
    pub y_frac: u8,
    pub vx: i16,
    pub vy: i16,
    pub r: u8,
    pub g: u8,
    pub b: u8,
    pub ttl: u8,
    pub spawn_ttl: u8,
}

One live particle.

Positions are in screen-space pixels (i16). Velocities are Q4.4 sub-pixel – vx = 32 means 2 px / frame. That keeps enough resolution for slow drift + fast bursts out of the same i16 channel.

Fields

x: i16

Top-left x position in pixels.

y: i16

Top-left y position in pixels.

x_frac: u8

Fraction of a pixel x has advanced, in sixteenths (0..=15). The pool carries the part of vx that does not fill a whole pixel here, so slow particles drift instead of freezing.

y_frac: u8

Fraction of a pixel y has advanced, in sixteenths (0..=15).

vx: i16

Velocity along x, Q4.4 pixels/frame.

vy: i16

Velocity along y, Q4.4 pixels/frame. Positive = downward.

r: u8

Colour at spawn – the renderer scales this by ttl / spawn_ttl for a fade-out.

g: u8

Green at spawn.

b: u8

Blue at spawn.

ttl: u8

Frames remaining. 0 = slot empty.

spawn_ttl: u8

TTL originally passed at spawn. Kept so the fade ratio is correct when different bursts have different lifespans.

Implementations

impl Particle

pub const fn empty() -> Self

A dead / empty slot. Useful for static-array init.

pub const fn is_alive(&self) -> bool

Is this particle currently alive and worth rendering?

Trait Implementations

impl Clone for Particle

fn clone(&self) -> Particle

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Particle

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

Formats the value using the given formatter.

impl Copy for Particle