unwrap: more tests
@@ -2,15 +2,16 @@ use serde::{Deserialize, Serialize};
/// Get phase wrap from x to y.
///
-/// Phases are modulo integer overflow.
+/// Phases are modulo integer overflow. The wraps have the same bias as
+/// the base data type itself.
///
/// Args:
/// * `x`: Old phase sample
/// * `y`: New phase sample
///
/// Returns:
-/// A tuple containg the (wrapped) phase difference and
-/// one times the direction of the wrap.
+/// A tuple containg the (wrapped) phase difference and the signum of the wrap.
+#[inline(always)]
pub fn get_wrap(x: i32, y: i32) -> (i32, i8) {
let delta = y.wrapping_sub(x);
let wrap = (delta >= 0) as i8 - (y >= x) as i8;
@@ -27,15 +28,15 @@ pub struct Unwrapper {
}
impl Unwrapper {
- /// Unwrap a new sample from a phase sequence and update the
- /// unwrapper state.
+ /// Unwrap a new sample from a phase sequence and update the unwrapper
+ /// state.
///
/// Args:
/// * `x`: New phase sample
///
/// Returns:
- /// A tuple containing the (wrapped) phase difference
- /// and the signed number of phase wraps corresponding to the new sample.
+ /// A tuple containing the (wrapped) phase difference and the signed
+ /// number of phase wraps accumulated to the new sample.
pub fn update(&mut self, x: i32) -> (i32, i32) {
let (dx, v) = get_wrap(self.x, x);
self.x = x;
@@ -51,18 +52,24 @@ mod tests {
fn mini() {
for (x0, x1, v) in [
(0i32, 0i32, 0i8),
- (1, 1, 0),
- (-1, -1, 0),
- (1, -1, 0),
- (-1, 1, 0),
+ (0, 1, 0),
+ (0, -1, 0),
+ (1, 0, 0),
+ (-1, 0, 0),
(0, 0x7fff_ffff, 0),
(-1, 0x7fff_ffff, -1),
+ (-2, 0x7fff_ffff, -1),
+ (-1, -0x8000_0000, 0),
(0, -0x8000_0000, 0),
(1, -0x8000_0000, 1),
(-0x6000_0000, 0x6000_0000, -1),
(0x6000_0000, -0x6000_0000, 1),
- (0x6000_0000, -0x6000_0000, 1),
- (0x6000_0000, -0x6000_0000, 1),
+ (-0x4000_0000, 0x3fff_ffff, 0),
+ (-0x4000_0000, 0x4000_0000, -1),
+ (-0x4000_0000, 0x4000_0001, -1),
+ (0x4000_0000, -0x3fff_ffff, 0),
+ (0x4000_0000, -0x4000_0000, 0),
+ (0x4000_0000, -0x4000_0001, 1),
]
.iter()
{
