Struct PiecewiseLinearCurve

pub struct PiecewiseLinearCurve<I> { /* private fields */ }

Represents a numeric value that changes over the course of the buffer.

We represent values changing over the course of the buffer as a piecewise linear curve, where the curve moving linearly from point to point.

Note that the curve is guaranteed to begin at 0, however it may end before the end of the buffer - in this case, the value remains constant until the end of the buffer.

Some invariants:

• There will always be at least one point
• The first point’s sample_offset will be 0
• sample_offsets will be monotonically increasing and only one point will appear for each sample_offset
• All point’s value will be between the parameter’s min and max

Implementations

impl<I: IntoIterator<Item = PiecewiseLinearCurvePoint> + Clone> PiecewiseLinearCurve<I>

pub fn new( points: I, buffer_size: usize, valid_range: RangeInclusive<f32>, ) -> Option<Self>

Construct a new PiecewiseLinearCurve from an iterator of points.

This will check the invariants for the curve, and if any are invalid, this will return None.

Examples

assert!(PiecewiseLinearCurve::new(
  vec![PiecewiseLinearCurvePoint { sample_offset: 0, value: 0.0 },
       PiecewiseLinearCurvePoint { sample_offset: 100, value: 1.0 }],
  128,
  0.0..=1.0,
).is_some());

// Curves must include at least one point
assert!(PiecewiseLinearCurve::new(vec![], 128, 0.0..=1.0).is_none());

// Curves can't go outside the valid range.
assert!(PiecewiseLinearCurve::new(
  vec![PiecewiseLinearCurvePoint { sample_offset: 0, value: 0.0 },
       PiecewiseLinearCurvePoint { sample_offset: 100, value: 2.0 }],
  128,
  0.0..=1.0,
).is_none());

// The curve must not go past the end of the buffer
assert!(PiecewiseLinearCurve::new(
  vec![PiecewiseLinearCurvePoint { sample_offset: 0, value: 0.0 },
       PiecewiseLinearCurvePoint { sample_offset: 128, value: 1.0 }],
  128,
  0.0..=1.0,
).is_none());

// The first point must be at 0
assert!(PiecewiseLinearCurve::new(
  vec![PiecewiseLinearCurvePoint { sample_offset: 50, value: 0.0 },
       PiecewiseLinearCurvePoint { sample_offset: 100, value: 1.0 }],
  128,
  0.0..=1.0,
).is_none());

// Sample offsets must monotonically increase
assert!(PiecewiseLinearCurve::new(
  vec![PiecewiseLinearCurvePoint { sample_offset: 0, value: 0.0 },
       PiecewiseLinearCurvePoint { sample_offset: 100, value: 1.0 },
       PiecewiseLinearCurvePoint { sample_offset: 50, value: 0.5 }],
  128,
  0.0..=1.0,
).is_none());

impl<I> PiecewiseLinearCurve<I>

pub fn buffer_size(&self) -> usize

Get the size of the buffer this curve is defined over.

Note that the last point may occur before the end of the buffer, in which case the value remains constant from that point until the end of the buffer.

Trait Implementations

impl<I: Clone> Clone for PiecewiseLinearCurve<I>

fn clone(&self) -> PiecewiseLinearCurve<I>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I: IntoIterator<Item = PiecewiseLinearCurvePoint>> IntoIterator for PiecewiseLinearCurve<I>

type Item = PiecewiseLinearCurvePoint

The type of the elements being iterated over.

type IntoIter = <I as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.