From 382ce168220bf680ec4635c0f4b95339d458c795 Mon Sep 17 00:00:00 2001
From: numzero <numzer0@yandex.ru>
Date: Sat, 29 Jun 2024 00:39:11 +0300
Subject: [PATCH] Remove the linear limiter as not smooth enough

---
 src/bin/flat/fns.rs | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/src/bin/flat/fns.rs b/src/bin/flat/fns.rs
index b1f7d7e..7c55c7b 100644
--- a/src/bin/flat/fns.rs
+++ b/src/bin/flat/fns.rs
@@ -5,16 +5,6 @@ pub trait Limiter {
 	fn derivative(&self, x: f32) -> f32;
 }
 
-pub struct LinearLimiter {
-	pub min: f32,
-	pub max: f32,
-}
-
-impl Limiter for LinearLimiter {
-	fn value(&self, x: f32) -> f32 { (self.min, self.max).inverse_lerp(x.abs()).clamp(0.0, 1.0) }
-	fn derivative(&self, x: f32) -> f32 { if x.abs() > self.min && x.abs() < self.max { x.signum() / (self.max - self.min) } else { 0.0 } }
-}
-
 pub struct SmoothstepLimiter {
 	pub min: f32,
 	pub max: f32,
@@ -100,21 +90,12 @@ mod test {
 			assert_abs_diff_eq!(testee.value(-x), 1., epsilon = ε);
 		}
 		for x in itertools_num::linspace(-mul * max, mul * max, 100) {
-			// Currently, the derivative is discontinuous at ±min and ±max... let’s just skip these for now.
-			if x.abs().abs_diff_eq(&min, δ) || x.abs().abs_diff_eq(&max, δ) {
-				continue;
-			}
 			let df_num = (testee.value(x + δ) - testee.value(x - δ)) / (2. * δ);
 			let df_expl = testee.derivative(x);
 			assert!(abs_diff_eq!(df_expl, df_num, epsilon = ε), "At x={x}, df/dx:\nnumerical: {df_num}\nexplicit:  {df_expl}\n");
 		}
 	}
 
-	#[test]
-	fn test_linear_limiter() {
-		test_limiter(LinearLimiter { min: 20.0, max: 30.0 }, 20.0, 30.0, 1.0 / 8.0);
-	}
-
 	#[test]
 	fn test_smoothstep_limiter() {
 		test_limiter(SmoothstepLimiter { min: 20.0, max: 30.0 }, 20.0, 30.0, 1.0 / 32.0);