refactor(core/rust): separate lerp and animations

pull/2448/head
tychovrahe 2 years ago committed by TychoVrahe
parent ce142ffe08
commit 7f2a995c54

@ -1,4 +1,7 @@
use crate::time::{Duration, Instant};
use crate::{
time::{Duration, Instant},
ui::lerp::{InvLerp, Lerp},
};
/// Running, time-based linear progression of a value.
pub struct Animation<T> {
@ -57,97 +60,3 @@ impl<T> Animation<T> {
}
}
}
/// Describes a type that can linearly interpolate (and extrapolate) based on
/// two values and a `f32` factor.
pub trait Lerp: Copy {
/// Interpolate/extrapolate between `a` and `b` and `t` as the factor.
fn lerp(a: Self, b: Self, t: f32) -> Self;
/// Interpolate between `a` and `b` by bounding the factor `t` in the range
/// `0..=1.0`.
fn lerp_bounded(a: Self, b: Self, t: f32) -> Self
where
Self: Sized,
{
match t {
t if t < 0.0 => a,
t if t > 1.0 => b,
t => Self::lerp(a, b, t),
}
}
}
/// Type that can compute an inverse of linear interpolation.
pub trait InvLerp: Copy {
/// Find a factor between `0.0` and `1.0` that defines the position of
/// `value` in the `min` and `max` closed interval.
fn inv_lerp(min: Self, max: Self, value: Self) -> f32;
}
macro_rules! impl_lerp_for_int {
($int: ident) => {
impl Lerp for $int {
fn lerp(a: Self, b: Self, t: f32) -> Self {
(a as f32 + t * (b - a) as f32) as Self
}
}
impl InvLerp for $int {
fn inv_lerp(min: Self, max: Self, value: Self) -> f32 {
(value - min) as f32 / (max - min) as f32
}
}
};
}
macro_rules! impl_lerp_for_uint {
($uint: ident) => {
impl Lerp for $uint {
fn lerp(a: Self, b: Self, t: f32) -> Self {
if a <= b {
(a as f32 + t * (b - a) as f32) as Self
} else {
(a as f32 - t * (a - b) as f32) as Self
}
}
}
impl InvLerp for $uint {
fn inv_lerp(min: Self, max: Self, value: Self) -> f32 {
if min <= max {
(value - min) as f32 / (max - min) as f32
} else {
(value - max) as f32 / (min - max) as f32
}
}
}
};
}
impl_lerp_for_int!(i32);
impl_lerp_for_uint!(u8);
impl_lerp_for_uint!(u16);
impl_lerp_for_uint!(u32);
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn lerp_for_int_and_uint() {
assert_eq!(i32::lerp(0, 8, 0.5), 4);
assert_eq!(i32::lerp(0, 8, -1.0), -8);
assert_eq!(i32::lerp(8, 0, 0.5), 4);
assert_eq!(u32::lerp(0, 8, 0.5), 4);
assert_eq!(u32::lerp(8, 0, -1.0), 16);
}
#[test]
fn inv_lerp_for_int_and_uint() {
assert!((i32::inv_lerp(0, 8, 4) - 0.5).abs() < f32::EPSILON);
assert!((i32::inv_lerp(0, 8, -8) - -1.0).abs() < f32::EPSILON);
assert!((i32::inv_lerp(8, 0, 4) - 0.5).abs() < f32::EPSILON);
assert!((u32::inv_lerp(0, 8, 4) - 0.5).abs() < f32::EPSILON);
}
}

@ -0,0 +1,93 @@
/// Describes a type that can linearly interpolate (and extrapolate) based on
/// two values and a `f32` factor.
pub trait Lerp: Copy {
/// Interpolate/extrapolate between `a` and `b` and `t` as the factor.
fn lerp(a: Self, b: Self, t: f32) -> Self;
/// Interpolate between `a` and `b` by bounding the factor `t` in the range
/// `0..=1.0`.
fn lerp_bounded(a: Self, b: Self, t: f32) -> Self
where
Self: Sized,
{
match t {
t if t < 0.0 => a,
t if t > 1.0 => b,
t => Self::lerp(a, b, t),
}
}
}
/// Type that can compute an inverse of linear interpolation.
pub trait InvLerp: Copy {
/// Find a factor between `0.0` and `1.0` that defines the position of
/// `value` in the `min` and `max` closed interval.
fn inv_lerp(min: Self, max: Self, value: Self) -> f32;
}
macro_rules! impl_lerp_for_int {
($int: ident) => {
impl Lerp for $int {
fn lerp(a: Self, b: Self, t: f32) -> Self {
(a as f32 + t * (b - a) as f32) as Self
}
}
impl InvLerp for $int {
fn inv_lerp(min: Self, max: Self, value: Self) -> f32 {
(value - min) as f32 / (max - min) as f32
}
}
};
}
macro_rules! impl_lerp_for_uint {
($uint: ident) => {
impl Lerp for $uint {
fn lerp(a: Self, b: Self, t: f32) -> Self {
if a <= b {
(a as f32 + t * (b - a) as f32) as Self
} else {
(a as f32 - t * (a - b) as f32) as Self
}
}
}
impl InvLerp for $uint {
fn inv_lerp(min: Self, max: Self, value: Self) -> f32 {
if min <= max {
(value - min) as f32 / (max - min) as f32
} else {
(value - max) as f32 / (min - max) as f32
}
}
}
};
}
impl_lerp_for_int!(i32);
impl_lerp_for_uint!(u8);
impl_lerp_for_uint!(u16);
impl_lerp_for_uint!(u32);
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn lerp_for_int_and_uint() {
assert_eq!(i32::lerp(0, 8, 0.5), 4);
assert_eq!(i32::lerp(0, 8, -1.0), -8);
assert_eq!(i32::lerp(8, 0, 0.5), 4);
assert_eq!(u32::lerp(0, 8, 0.5), 4);
assert_eq!(u32::lerp(8, 0, -1.0), 16);
}
#[test]
fn inv_lerp_for_int_and_uint() {
assert!((i32::inv_lerp(0, 8, 4) - 0.5).abs() < f32::EPSILON);
assert!((i32::inv_lerp(0, 8, -8) - -1.0).abs() < f32::EPSILON);
assert!((i32::inv_lerp(8, 0, 4) - 0.5).abs() < f32::EPSILON);
assert!((u32::inv_lerp(0, 8, 4) - 0.5).abs() < f32::EPSILON);
}
}

@ -7,6 +7,7 @@ pub mod constant;
pub mod display;
pub mod event;
pub mod geometry;
pub mod lerp;
mod util;
#[cfg(feature = "micropython")]

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