embedded-plots/src/range_conv.rs
Michał Chodzikiewicz e2895dbc26 Single- and Poly- Plot
2020-12-21 00:50:22 +01:00

38 lines
1.3 KiB
Rust

use core::ops::{Range, Add, Sub, Mul, Div};
pub trait Scalable<T>
where
T: Copy + Add<Output=T> + Sub<Output=T> + Mul<Output=T> + Div<Output=T>,
{
fn scale_between_ranges(&self, input_range: &Range<T>, output_range: &Range<T>) -> T;
}
impl<T> Scalable<T> for T
where
T: Copy + Add<Output=T> + Sub<Output=T> + Mul<Output=T> + Div<Output=T>,
{
fn scale_between_ranges(&self, input_range: &Range<T>, output_range: &Range<T>) -> T
{
(*self - input_range.start) * (output_range.end - output_range.start)
/ (input_range.end - input_range.start) + output_range.start
}
}
#[cfg(test)]
mod tests {
use core::ops::Range;
use test_case::test_case;
use crate::range_conv::Scalable;
#[test_case(0..10, 0..10, 5 => 5; "equal ranges")]
#[test_case(0..10, 0..20, 5 => 10; "double")]
#[test_case(0..20, 0..10, 10 => 5; "half")]
#[test_case(- 20..20, 0..10, 0 => 5; "negative input range")]
#[test_case(0..10, - 20..20, 5 => 0; "negative output range")]
#[test_case(0..10, 10..0, 2 => 8; "reversing")]
#[test_case(- 20..20, 0..20, - 10 => 5; "reversing negative range")]
fn convert(in_range: Range<i32>, out_range: Range<i32>, val: i32) -> i32 {
val.scale_between_ranges(&in_range, &out_range)
}
}