Trait Effect 

pub trait Effect {
    // Required methods
    fn is_active(&self) -> bool;
    fn activate(&mut self);
    fn deactivate(&mut self);
    fn tick(&mut self);
    fn draw(&mut self, sink: &mut dyn EffectSink);
}

Lifecycle contract for a platform-level visual effect.

Boards (BSPs) drive effects through this trait: start one with Effect::activate, advance per-frame state with Effect::tick, describe the current frame with Effect::draw into an EffectSink, and tear down with Effect::deactivate. Effect::is_active gates whether the host needs to keep calling tick / draw.

The trait is object-safe (no generics on any required method) so hosts can polymorphism-dispatch over Box<dyn Effect> when they want a pool of heterogeneous effects. The generic CPU convenience EffectExt::paint lives on a supertrait to preserve that.

Required Methods

fn is_active(&self) -> bool

Returns true while this effect is contributing work.

The effect is expected to drop to false of its own accord when its animation cycle finishes (for example, a crawl scrolling past its end). Hosts can also drive the flag down explicitly via Effect::deactivate.

fn activate(&mut self)

Prepare internal buffers and start a fresh animation cycle.

Re-activating an already-active effect resets it to the start of a new cycle.

fn deactivate(&mut self)

Stop animating.

Subsequent Effect::tick calls are a no-op until Effect::activate is called again.

fn tick(&mut self)

Advance per-frame animation state by exactly one frame.

Hosts pace this from their frame clock (wall-clock or VSYNC) so that visible motion tracks the declared rate regardless of CPU load variations.

fn draw(&mut self, sink: &mut dyn EffectSink)

Emit the current frame’s render ops into sink.

The effect owns no framebuffer memory of its own. The sink owns the destination surface (directly, in the case of BlitterSink) or accumulates ops for later flushing (a future Dma2dBatchSink).

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors