Struct Decay 

pub struct Decay { /* private fields */ }

Natural decay behaviour of the simulated phosphor screen.

We provide two tuning knobs:

• the decay between consecutive samples in the same trace
• the decay between consecutive traces

The former models the finite time it takes for the scope to trace a single sweep across the screen. The latter models the time between two shots.

screen_decay

The decay factor applied to the entire phosphor screen, applied the next time when Renderer::render_intermediate() is called. Each pixel is faded according to a factor of exp(-screen_decay). A value of either exactly 0.0 (no decay, waveforms are drawn on top of each other) or +INFINITY (new waveforms completely erase previous ones) bypass the blending logic and are slightly more efficient. A value below 0 is clamped.

sample_decay

The decay factor applied between consecutive samples in the same trace. The very last sample is painted with full nominal intensity, and the N-th sample before the last has its intensity scaled by a factor (1 - sample_decay).pow(N). Setting sample_decay to 0.0 will render all samples at full intensity. A value outside the [0, 1] range is clamped.

Implementations

impl Decay

pub fn new(screen_decay: f32, sample_decay: f32) -> Decay

pub fn with_sample_decay(self, sample_decay: f32) -> Decay

pub fn with_screen_decay(self, screen_decay: f32) -> Decay

impl Decay

Ready-made configurations for common use cases.

pub fn no_decay() -> Decay

No decay. All render commands draw on top of each other.

pub fn instant_redraw() -> Decay

No sample-to-sample decay, and no persistence between traces.

Useful for ‘single-shot digital storage oscilloscope’ applications, where e.g. a full trace is acquired once, and then frozen. The user can pan and zoom the viewport for inspecting the waveform, without the trace fading.

This is what the Default::default() implementation returns.

pub fn continuous_update( time_since_last_trace: f32, persistence: f32, trace_length: usize, ) -> Decay

Decay simulating a continuously updated waveform with no dead-time between shots.

Think of a free-running oscilloscope in XY mode.

Arguments

• time_since_last_frame - Time (e.g. in seconds) since the last frame was drawn to the screen
• persistence - Time (same units) for the phosphor screen to decay to 37% (1/e) of its original brightness.
• trace_length - The number of samples in the waveform about to be drawn.

Trait Implementations

impl Clone for Decay

fn clone(&self) -> Decay

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Decay

impl Debug for Decay

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

Formats the value using the given formatter.

impl Default for Decay

fn default() -> Self

Returns the “default value” for a type.