From 5991fa600dd6a3fb303ec494538f65182cfc6aff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Bourdeauducq?= <sb@m-labs.hk>
Date: Tue, 31 Dec 2024 17:04:37 +0800
Subject: [PATCH] phase_t

---
 dsp_lib.h | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/dsp_lib.h b/dsp_lib.h
index b8d7553..10817ac 100644
--- a/dsp_lib.h
+++ b/dsp_lib.h
@@ -3,18 +3,21 @@
 #include <cstdint>
 #include <complex>
 
-static uint32_t frequency_to_ftw(double f) {
-    return f*(double)UINT32_MAX;
+typedef uint32_t phase_t;
+#define PHASE_MAX UINT32_MAX
+
+static phase_t frequency_to_ftw(double f) {
+    return f*(double)PHASE_MAX;
 }
 
 class DDS {
     private:
-        uint32_t phase = 0;
+        phase_t phase = 0;
     public:
-        uint32_t ftw = 0;
+        phase_t ftw = 0;
         double get() {
             phase += ftw;  // wraps on overflow
-            return sin(phase*2.0*M_PI/(double)UINT32_MAX);
+            return sin(phase*2.0*M_PI/(double)PHASE_MAX);
         }
 };
 
@@ -41,10 +44,10 @@ template<unsigned int order>
 class Lockin {
     private:
         double scale;
-        uint32_t phase = 0;
+        phase_t phase = 0;
         Lowpass<std::complex<double>, order> lpf;
     public:
-        uint32_t ftw = 0;
+        phase_t ftw = 0;
         void set_scale(double s) {
             scale = s;
         }
@@ -53,7 +56,7 @@ class Lockin {
         }
         std::complex<double> update(double x) {
             std::complex<double> rotated;
-            rotated = x*std::polar(scale, phase*2.0*M_PI/(double)UINT32_MAX);
+            rotated = x*std::polar(scale, phase*2.0*M_PI/(double)PHASE_MAX);
             phase -= ftw;  // wraps on underflow
             return lpf.update(rotated);
         }