diff options
Diffstat (limited to 'vendor/plotters/src/coord/ranged1d/types/slice.rs')
-rw-r--r-- | vendor/plotters/src/coord/ranged1d/types/slice.rs | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/vendor/plotters/src/coord/ranged1d/types/slice.rs b/vendor/plotters/src/coord/ranged1d/types/slice.rs new file mode 100644 index 000000000..13be3d7f4 --- /dev/null +++ b/vendor/plotters/src/coord/ranged1d/types/slice.rs @@ -0,0 +1,100 @@ +use crate::coord::ranged1d::{ + AsRangedCoord, DefaultFormatting, DiscreteRanged, KeyPointHint, Ranged, +}; +use std::ops::Range; + +/// A range that is defined by a slice of values. +/// +/// Please note: the behavior of constructing an empty range may cause panic +#[derive(Clone)] +pub struct RangedSlice<'a, T: PartialEq>(&'a [T]); + +impl<'a, T: PartialEq> Ranged for RangedSlice<'a, T> { + type FormatOption = DefaultFormatting; + type ValueType = &'a T; + + fn range(&self) -> Range<&'a T> { + // If inner slice is empty, we should always panic + &self.0[0]..&self.0[self.0.len() - 1] + } + + fn map(&self, value: &Self::ValueType, limit: (i32, i32)) -> i32 { + match self.0.iter().position(|x| &x == value) { + Some(pos) => { + let pixel_span = limit.1 - limit.0; + let value_span = self.0.len() - 1; + (f64::from(limit.0) + + f64::from(pixel_span) + * (f64::from(pos as u32) / f64::from(value_span as u32))) + .round() as i32 + } + None => limit.0, + } + } + + fn key_points<Hint: KeyPointHint>(&self, hint: Hint) -> Vec<Self::ValueType> { + let max_points = hint.max_num_points(); + let mut ret = vec![]; + let intervals = (self.0.len() - 1) as f64; + let step = (intervals / max_points as f64 + 1.0) as usize; + for idx in (0..self.0.len()).step_by(step) { + ret.push(&self.0[idx]); + } + ret + } +} + +impl<'a, T: PartialEq> DiscreteRanged for RangedSlice<'a, T> { + fn size(&self) -> usize { + self.0.len() + } + + fn index_of(&self, value: &&'a T) -> Option<usize> { + self.0.iter().position(|x| &x == value) + } + + fn from_index(&self, index: usize) -> Option<&'a T> { + if self.0.len() <= index { + return None; + } + Some(&self.0[index]) + } +} + +impl<'a, T: PartialEq> From<&'a [T]> for RangedSlice<'a, T> { + fn from(range: &'a [T]) -> Self { + RangedSlice(range) + } +} + +impl<'a, T: PartialEq> AsRangedCoord for &'a [T] { + type CoordDescType = RangedSlice<'a, T>; + type Value = &'a T; +} + +#[cfg(test)] +mod test { + use super::*; + #[test] + fn test_slice_range() { + let my_slice = [1, 2, 3, 0, -1, -2]; + let slice_range: RangedSlice<i32> = my_slice[..].into(); + + assert_eq!(slice_range.range(), &1..&-2); + assert_eq!( + slice_range.key_points(6), + my_slice.iter().collect::<Vec<_>>() + ); + assert_eq!(slice_range.map(&&0, (0, 50)), 30); + } + + #[test] + fn test_slice_range_discrete() { + let my_slice = [1, 2, 3, 0, -1, -2]; + let slice_range: RangedSlice<i32> = my_slice[..].into(); + + assert_eq!(slice_range.size(), 6); + assert_eq!(slice_range.index_of(&&3), Some(2)); + assert_eq!(slice_range.from_index(2), Some(&3)); + } +} |