Tested the cubic interpolation now properly, also against alternative maths
This commit is contained in:
Weird Constructor
parent
1ee4af6cd1
commit
5a4dc0e2aa
2 changed files with 132 additions and 31 deletions
|
|
@ -901,14 +901,14 @@ fn fclampc<F: Flt>(x: F, mi: f64, mx: f64) -> F {
|
|||
///```
|
||||
/// use hexodsp::dsp::helpers::cubic_interpolate;
|
||||
///
|
||||
/// let buf [f32; 9] = [1.0, 0.2, 0.4, 0.5, 0.7, 0.9, 1.0, 0.3, 0.3];
|
||||
/// let buf : [f32; 9] = [1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2];
|
||||
/// let pos = 3.3_f32;
|
||||
///
|
||||
/// let i = pos.floor();
|
||||
/// let i = pos.floor() as usize;
|
||||
/// let f = pos.fract();
|
||||
///
|
||||
/// let res = cubic_interpolate(&buf[..], buf.len(), i, f);
|
||||
/// assert_eq!((res - 0.4).abs() < 0.2);
|
||||
/// assert!((res - 0.67).abs() < 0.2_f32);
|
||||
///```
|
||||
#[inline]
|
||||
pub fn cubic_interpolate<F: Flt>(data: &[F], len: usize, index: usize, fract: F) -> F {
|
||||
|
|
@ -931,7 +931,31 @@ pub fn cubic_interpolate<F: Flt>(data: &[F], len: usize, index: usize, fract: F)
|
|||
let a = w + v + (x2 - x0) * f(0.5);
|
||||
let b_neg = w + a;
|
||||
|
||||
(((a * fract) - b_neg) * fract + c) * fract + x0
|
||||
let res = (((a * fract) - b_neg) * fract + c) * fract + x0;
|
||||
|
||||
// let rr2 =
|
||||
// x0 + f::<F>(0.5) * fract * (
|
||||
// x1 - xm1 + fract * (
|
||||
// f::<F>(4.0) * x1
|
||||
// + f::<F>(2.0) * xm1
|
||||
// - f::<F>(5.0) * x0
|
||||
// - x2
|
||||
// + fract * (f::<F>(3.0) * (x0 - x1) - xm1 + x2)));
|
||||
|
||||
// eprintln!(
|
||||
// "index={} fract={:6.4} xm1={:6.4} x0={:6.4} x1={:6.4} x2={:6.4} = {:6.4} <> {:6.4}",
|
||||
// index, fract.to_f64().unwrap(), xm1.to_f64().unwrap(), x0.to_f64().unwrap(), x1.to_f64().unwrap(), x2.to_f64().unwrap(),
|
||||
// res.to_f64().unwrap(),
|
||||
// rr2.to_f64().unwrap()
|
||||
// );
|
||||
|
||||
// eprintln!(
|
||||
// "index={} fract={:6.4} xm1={:6.4} x0={:6.4} x1={:6.4} x2={:6.4} = {:6.4}",
|
||||
// index, fract.to_f64().unwrap(), xm1.to_f64().unwrap(), x0.to_f64().unwrap(), x1.to_f64().unwrap(), x2.to_f64().unwrap(),
|
||||
// res.to_f64().unwrap(),
|
||||
// );
|
||||
|
||||
res
|
||||
}
|
||||
|
||||
#[derive(Debug, Clone, Default)]
|
||||
|
|
@ -1067,14 +1091,18 @@ impl<F: Flt> DelayBuffer<F> {
|
|||
let offs = s_offs.floor().to_usize().unwrap_or(0) % len;
|
||||
let fract = s_offs.fract();
|
||||
|
||||
// (offs + 1) offset for compensating that self.wr points to the next
|
||||
// unwritten position.
|
||||
// Additional (offs + 1 + 1) offset for cubic_interpolate, which
|
||||
// interpolates into the past through the delay buffer.
|
||||
let i = (self.wr + len) - (offs + 2);
|
||||
let res = cubic_interpolate(data, len, i, f::<F>(1.0) - fract);
|
||||
// eprintln!(
|
||||
// "cubic at={} ({:6.4}) res={:6.4}",
|
||||
// i % len,
|
||||
// s_offs.to_f64().unwrap(),
|
||||
// res.to_f64().unwrap()
|
||||
// );
|
||||
// eprintln!(
|
||||
// "cubic at={} ({:6.4}) res={:6.4}",
|
||||
// i % len,
|
||||
// s_offs.to_f64().unwrap(),
|
||||
// res.to_f64().unwrap()
|
||||
// );
|
||||
res
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -110,6 +110,51 @@ fn check_cubic_interpolate() {
|
|||
use crate::helpers::cubic_interpolate;
|
||||
let data = [1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.0];
|
||||
|
||||
let mut samples_out = vec![];
|
||||
let mut pos = 0.0_f32;
|
||||
let pos_inc = 0.5_f32;
|
||||
for _ in 0..30 {
|
||||
let i = pos.floor() as usize;
|
||||
let f = pos.fract();
|
||||
samples_out.push(cubic_interpolate(&data[..], data.len(), i, f));
|
||||
pos += pos_inc;
|
||||
}
|
||||
assert_vec_feq!(
|
||||
samples_out,
|
||||
vec![
|
||||
1.0,
|
||||
1.01875,
|
||||
0.9,
|
||||
0.85,
|
||||
0.8,
|
||||
0.75,
|
||||
0.7,
|
||||
0.65,
|
||||
0.6,
|
||||
0.55,
|
||||
0.5,
|
||||
0.45,
|
||||
0.4,
|
||||
0.35000002,
|
||||
0.3,
|
||||
0.25,
|
||||
0.2,
|
||||
0.15,
|
||||
0.1,
|
||||
-0.018750004,
|
||||
0.0,
|
||||
0.49999997,
|
||||
1.0,
|
||||
1.01875,
|
||||
0.9,
|
||||
0.85,
|
||||
0.8,
|
||||
0.75,
|
||||
0.7,
|
||||
0.65
|
||||
]
|
||||
);
|
||||
|
||||
let mut samples_out = vec![];
|
||||
let mut pos = 0.0_f32;
|
||||
let pos_inc = 0.1_f32;
|
||||
|
|
@ -148,23 +193,7 @@ fn check_delaybuffer_cubic_interpolation() {
|
|||
|
||||
let mut samples_out = vec![];
|
||||
let mut pos = 0.0;
|
||||
let pos_inc = 0.5;
|
||||
for _ in 0..20 {
|
||||
samples_out.push(buf.cubic_interpolate_at_s(pos));
|
||||
pos += pos_inc;
|
||||
}
|
||||
|
||||
assert_vec_feq!(
|
||||
samples_out,
|
||||
vec![
|
||||
1.0, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35000002, 0.3,
|
||||
0.25, 0.2, 0.15, 0.1, 0.05
|
||||
]
|
||||
);
|
||||
|
||||
let mut samples_out = vec![];
|
||||
let mut pos = 0.0;
|
||||
let pos_inc = 0.2;
|
||||
let pos_inc = 0.1;
|
||||
for _ in 0..30 {
|
||||
samples_out.push(buf.cubic_interpolate_at_s(pos));
|
||||
pos += pos_inc;
|
||||
|
|
@ -173,10 +202,54 @@ fn check_delaybuffer_cubic_interpolation() {
|
|||
assert_vec_feq!(
|
||||
samples_out,
|
||||
vec![
|
||||
1.0, 0.98, 0.96, 0.94, 0.91999996, 0.9, 0.88, 0.85999995, 0.84, 0.82, 0.8, 0.78, 0.76,
|
||||
0.73999995, 0.71999997, 0.6999999, 0.67999995, 0.65999997, 0.6399999, 0.61999995,
|
||||
0.59999996, 0.58, 0.56, 0.54, 0.52000004, 0.50000006, 0.48000008, 0.4600001,
|
||||
0.44000012, 0.42000014
|
||||
1.0, 1.03455, 1.0504, 1.05085, 1.0392, 1.01875, 0.99279994, 0.9646499, 0.9375999,
|
||||
0.91494995, 0.9, 0.89, 0.87999994, 0.86999995, 0.85999995, 0.84999996, 0.84, 0.83,
|
||||
0.82, 0.80999994, 0.8, 0.79, 0.78000003, 0.77000004, 0.76, 0.75, 0.74, 0.73, 0.72,
|
||||
0.71000004
|
||||
]
|
||||
);
|
||||
|
||||
let mut samples_out = vec![];
|
||||
let mut pos = 0.0;
|
||||
let pos_inc = 0.5;
|
||||
for _ in 0..30 {
|
||||
samples_out.push(buf.cubic_interpolate_at_s(pos));
|
||||
pos += pos_inc;
|
||||
}
|
||||
|
||||
assert_vec_feq!(
|
||||
samples_out,
|
||||
vec![
|
||||
1.0,
|
||||
1.01875,
|
||||
0.9,
|
||||
0.85,
|
||||
0.8,
|
||||
0.75,
|
||||
0.7,
|
||||
0.65,
|
||||
0.6,
|
||||
0.55,
|
||||
0.5,
|
||||
0.45,
|
||||
0.4,
|
||||
0.35000002,
|
||||
0.3,
|
||||
0.25,
|
||||
0.2,
|
||||
0.15,
|
||||
0.1,
|
||||
0.043750003,
|
||||
0.0,
|
||||
-0.00625,
|
||||
0.0,
|
||||
0.0,
|
||||
0.0,
|
||||
0.0,
|
||||
0.0,
|
||||
0.0,
|
||||
0.0,
|
||||
0.0
|
||||
]
|
||||
);
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue