Add clamp_{lower,upper}
@@ -371,17 +371,55 @@ pub fn clamp<T: PartialOrd>(input: T, min: T, max: T) -> T {
}
}
+/// A value bounded by a minimum value
+///
+/// If input is less than min then this returns min.
+/// Otherwise this returns input.
+/// Preserves `NaN` different from `min`.
+#[inline]
+pub fn clamp_lower<T: PartialOrd>(input: T, min: T) -> T {
+ if input < min {
+ min
+ } else {
+ input
+ }
+}
+
+/// A value bounded by a maximum value
+///
+/// If input is less than min then this returns min.
+/// Otherwise this returns input.
+/// Preserves `NaN` different from `max`.
+#[inline]
+pub fn clamp_upper<T: PartialOrd>(input: T, max: T) -> T {
+ if input > max {
+ max
+ } else {
+ input
+ }
+}
+
#[test]
fn clamp_test() {
// Int test
assert_eq!(1, clamp(1, -1, 2));
assert_eq!(-1, clamp(-2, -1, 2));
assert_eq!(2, clamp(3, -1, 2));
+ assert_eq!(1, clamp_lower(1, -1));
+ assert_eq!(-1, clamp_lower(-2, -1));
+ assert_eq!(-1, clamp_upper(1, -1));
+ assert_eq!(-2, clamp_upper(-2, -1));
// Float test
assert_eq!(1.0, clamp(1.0, -1.0, 2.0));
assert_eq!(-1.0, clamp(-2.0, -1.0, 2.0));
assert_eq!(2.0, clamp(3.0, -1.0, 2.0));
+ assert_eq!(1.0, clamp_lower(1.0, -1.0));
+ assert_eq!(-1.0, clamp_lower(-2.0, -1.0));
+ assert_eq!(-1.0, clamp_upper(1.0, -1.0));
+ assert_eq!(-2.0, clamp_upper(-2.0, -1.0));
+ assert!(clamp_lower(std::f32::NAN, 1.0).is_nan());
+ assert!(clamp_upper(std::f32::NAN, 1.0).is_nan());
}
#[test]
