From 46a7361349a7ddd9f3af626286cd155385a0f174 Mon Sep 17 00:00:00 2001
From: Kuba <132459354+KubaPro010@users.noreply.github.com>
Date: Fri, 8 Aug 2025 23:08:05 +0200
Subject: [PATCH] is this vibe coding?

---
 filter/iir.c | 23 +++++++++--------------
 filter/iir.h |  7 +++----
 2 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/filter/iir.c b/filter/iir.c
index 55129d3..387be65 100644
--- a/filter/iir.c
+++ b/filter/iir.c
@@ -16,21 +16,16 @@ inline float apply_preemphasis(ResistorCapacitor *filter, float sample) {
 }
 
 void tilt_init(TiltCorrectionFilter* filter, float correction_strength) {
-    filter->alpha = 0.9999f;
-    filter->gain = correction_strength;  // Can be > 1.0
-    filter->x_prev = 0.0f;
-    filter->y_prev = 0.0f;
+    f->tilt = correction_strength;
+    f->prev_in = 0.0f;
+    f->prev_out = 0.0f;
 }
 
 float tilt(TiltCorrectionFilter* filter, float input) {
-    // High-pass filter
-    float hp_out = filter->alpha * (filter->y_prev + input - filter->x_prev);
-    
-    // Apply gain and add back to original
-    float output = input + filter->gain * hp_out;
-    
-    filter->x_prev = input;
-    filter->y_prev = hp_out;
-    
-    return output;
+    float out = input + f->tilt * (input - f->prev_in);
+
+    f->prev_in = input;
+    f->prev_out = out;
+
+    return out;
 }
\ No newline at end of file
diff --git a/filter/iir.h b/filter/iir.h
index 0edd5b5..5d925f0 100644
--- a/filter/iir.h
+++ b/filter/iir.h
@@ -14,10 +14,9 @@ void init_preemphasis(ResistorCapacitor *filter, float tau, float sample_rate, f
 float apply_preemphasis(ResistorCapacitor *filter, float sample);
 
 typedef struct {
-    float alpha;
-	float x_prev;
-	float y_prev;
-	float gain;
+    float tilt;     // Tilt amount (-1.0 to +1.0 typical)
+    float prev_in;  // Previous input sample
+    float prev_out; // Previous output sample
 } TiltCorrectionFilter;
 
 void tilt_init(TiltCorrectionFilter* filter, float alpha);