From 830703589deece2f000bbf16dee41079511136a7 Mon Sep 17 00:00:00 2001
From: Thomas Schmid <tom@lfence.de>
Date: Sun, 19 Jun 2022 12:33:59 +0200
Subject: [PATCH] pt1: implement as template class

Signed-off-by: Thomas Schmid <tom@lfence.de>
---
 firmware/include/pt1.h    | 22 +++++++++++++++-------
 firmware/src/pt1.cpp      | 15 ---------------
 firmware/temp/vumeter.cpp | 11 ++++-------
 3 files changed, 19 insertions(+), 29 deletions(-)
 delete mode 100644 firmware/src/pt1.cpp

diff --git a/firmware/include/pt1.h b/firmware/include/pt1.h
index 8e9a039..4d08d54 100644
--- a/firmware/include/pt1.h
+++ b/firmware/include/pt1.h
@@ -1,10 +1,18 @@
 #pragma once
 
-struct pt1_state {
-    float y_n1;
-    float K;
-    float T;
-};
+template<class T>
+struct Pt1 {
+    T y_n1;
+    T K;
+    T T1;
 
-void pt1_init(struct pt1_state *state, float K, float T);
-float pt1_update(struct pt1_state *state, float u, float dt);
\ No newline at end of file
+    /* PT1: y = y_(n-1) + (Ku - y_(n-1)) * dt/T1 */
+    Pt1(T K, T T1) : T1(T1), K(K) {};
+
+    T update(T u, T dt)
+    {
+        T y = this->y_n1 + (this->K * u - this->y_n1) * dt / this->T1;
+        this->y_n1 = y;
+        return y;
+    }
+};
\ No newline at end of file
diff --git a/firmware/src/pt1.cpp b/firmware/src/pt1.cpp
deleted file mode 100644
index 7c9b623..0000000
--- a/firmware/src/pt1.cpp
+++ /dev/null
@@ -1,15 +0,0 @@
-#include "pt1.h"
-
-void pt1_init(struct pt1_state *state, float K, float T)
-{
-    state->K = K;
-    state->T = T;
-    state->y_n1 = 0.0f;
-}
-
-float pt1_update(struct pt1_state *state, float u, float dt)
-{
-    float y = state->y_n1 + (state->K * u - state->y_n1) * dt / state->T;
-    state->y_n1 = y;
-    return y;
-}
\ No newline at end of file
diff --git a/firmware/temp/vumeter.cpp b/firmware/temp/vumeter.cpp
index 2d5ac39..09bc8f9 100644
--- a/firmware/temp/vumeter.cpp
+++ b/firmware/temp/vumeter.cpp
@@ -9,17 +9,14 @@ float vu_filt = 0.0f;
 float vu_filt_slow = 0.0f;
 float dt;
 
-struct pt1_state vu_pt1_fast;
-struct pt1_state vu_pt1_slow;
+Pt1<float> vu_pt1_fast{1.f, 1.f};
+Pt1<float> vu_pt1_slow{1.f, 0.05f};
 
 void setup()
 {
     zauberstab_init();
     Serial.begin(115200);
     FastLED.setBrightness(100);
-
-    pt1_init(&vu_pt1_slow, 1, 1.f);
-    pt1_init(&vu_pt1_fast, 1, 0.05);
 }
 
 void loop() {
@@ -34,8 +31,8 @@ void loop() {
     EVERY_N_MILLIS(10){
 
         float vu = 20 * log10f(rms_avg);
-        vu_filt = pt1_update(&vu_pt1_fast, vu, 0.01f);
-        vu_filt_slow = pt1_update(&vu_pt1_slow, vu_filt, 0.01f);
+        vu_filt = vu_pt1_fast.update(vu, 0.01f);
+        vu_filt_slow = vu_pt1_slow.update(vu_filt, 0.01f);
         //Serial.println(vu);
         int max_led = vu_filt;
         int top_led = vu_filt_slow;