From fa6af749de3ea9cba9ee3d0dfeaeae30b817c59f Mon Sep 17 00:00:00 2001
From: Weird Constructor <weirdconstructor@gmail.com>
Date: Thu, 21 Jul 2022 02:03:16 +0200
Subject: [PATCH] added AllPass::next_linear

---
 src/dsp/helpers.rs | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/dsp/helpers.rs b/src/dsp/helpers.rs
index f24782c..4931e85 100644
--- a/src/dsp/helpers.rs
+++ b/src/dsp/helpers.rs
@@ -1221,7 +1221,8 @@ impl<F: Flt> AllPass<F> {
         self.delay.tap_n(time_ms)
     }
 
-    /// Retrieve the next sample from the all-pass filter while feeding in the next.
+    /// Retrieve the next (cubic interpolated) sample from the all-pass
+    /// filter while feeding in the next.
     ///
     /// * `time_ms` - Delay time in milliseconds.
     /// * `g` - Feedback factor (usually something around 0.7 is common)
@@ -1233,6 +1234,20 @@ impl<F: Flt> AllPass<F> {
         self.delay.feed(input);
         input * g + s
     }
+
+    /// Retrieve the next (linear interpolated) sample from the all-pass
+    /// filter while feeding in the next.
+    ///
+    /// * `time_ms` - Delay time in milliseconds.
+    /// * `g` - Feedback factor (usually something around 0.7 is common)
+    /// * `v` - The new input sample to feed the filter.
+    #[inline]
+    pub fn next_linear(&mut self, time_ms: F, g: F, v: F) -> F {
+        let s = self.delay.linear_interpolate_at(time_ms);
+        let input = v + -g * s;
+        self.delay.feed(input);
+        input * g + s
+    }
 }
 
 #[derive(Debug, Clone)]