From d4cb319ddb178258bed1a32a9862fa463e09ccce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Bourdeauducq?= <sb@m-labs.hk>
Date: Sun, 5 Jan 2025 15:32:26 +0800
Subject: [PATCH] add multiplier

---
 dsp_lib.h   |  6 +++++-
 sndlock.cpp | 36 +++++++++++++++++++++++++-----------
 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/dsp_lib.h b/dsp_lib.h
index 8962636..73ae85b 100644
--- a/dsp_lib.h
+++ b/dsp_lib.h
@@ -47,6 +47,7 @@ template<unsigned int order>
 class Lockin {
     private:
         double scale = 1.0;
+        phase_t multiplier = 1;
         phase_t phase = 0;
         Lowpass<std::complex<double>, order> lpf;
     public:
@@ -54,12 +55,15 @@ class Lockin {
         void set_scale(double s) {
             scale = s;
         }
+        void set_multiplier(phase_t m) {
+            multiplier = m;
+        }
         void set_bandwidth(double f) {
             lpf.set_bandwidth(f);
         }
         std::complex<double> update(double x) {
             std::complex<double> rotated;
-            rotated = x*std::polar(scale, phase*2.0*M_PI/(double)PHASE_MAX);
+            rotated = x*std::polar(scale, multiplier*phase*2.0*M_PI/(double)PHASE_MAX);
             phase -= ftw;  // wraps on underflow
             return lpf.update(rotated);
         }
diff --git a/sndlock.cpp b/sndlock.cpp
index 518b140..05d17a8 100644
--- a/sndlock.cpp
+++ b/sndlock.cpp
@@ -35,6 +35,7 @@ static std::atomic<int> in_wave_trigger;
 static std::mutex in_wave_mutex;
 static float in_wave[HIST_DEPTH];
 
+static std::atomic<int> multiplier[SND_PCHAN];
 static std::atomic<double> lpf_bandwidth[SND_PCHAN];
 static std::mutex li_hist_mutex;
 static std::atomic<bool> li_hist_pause[SND_PCHAN];
@@ -108,8 +109,10 @@ static void dsp_thread()
         poll(pfd, nfds, INFTIM);
         int revents = sio_revents(hdl, pfd);
 
-        for(int i=0;i<SND_PCHAN;i++)
+        for(int i=0;i<SND_PCHAN;i++) {
+            lockin[i].set_multiplier(multiplier[i]);
             lockin[i].set_bandwidth(lpf_bandwidth[i]/SND_RATE);
+        }
 
         if(revents & POLLOUT) {
             if(buf_out_offset == sizeof(buf_out)) {
@@ -263,6 +266,7 @@ int main(int argc, char* argv[])
     for(int i=0;i<SND_PCHAN;i++) {
         frequency[i] = 441.0 + 202.0*i;
         amplitude[i] = 1.0;
+        multiplier[i] = 1;
         lpf_bandwidth[i] = 10.0;
     }
 
@@ -341,6 +345,26 @@ int main(int argc, char* argv[])
 
                 sprintf(str, "Channel %d", i);
                 ImGui::SeparatorText(str);
+                ImGui::AlignTextToFramePadding();
+                ImGui::Text("multiplier:");
+                int multiplier_l = multiplier[i];
+                ImGui::SameLine();
+                sprintf(str, "f##%d", i);
+                ImGui::RadioButton(str, &multiplier_l, 1);
+                ImGui::SameLine();
+                sprintf(str, "2f##%d", i);
+                ImGui::RadioButton(str, &multiplier_l, 2);
+                ImGui::SameLine();
+                sprintf(str, "3f##%d", i);
+                ImGui::RadioButton(str, &multiplier_l, 3);
+                multiplier[i] = multiplier_l;
+                ImGui::SameLine();
+                ImGui::Text("/");
+                bool pause_l = li_hist_pause[i];
+                ImGui::SameLine();
+                sprintf(str, "pause##%d", i);
+                ImGui::Checkbox(str, &pause_l);
+                li_hist_pause[i] = pause_l;
                 sprintf(str, "LPF BW##%d", i);
                 float lpf_bandwidth_l = lpf_bandwidth[i];
                 ImGui::SliderFloat(str, &lpf_bandwidth_l, 0.5f, 200.0f);
@@ -354,16 +378,6 @@ int main(int argc, char* argv[])
                     ImGui::PlotLines(str, li_hist_mag[i], HIST_DEPTH, 0, 0, -0.0f, 0.1f*plot_scale[i], ImVec2(0.0f, 200.0f));
                     sprintf(str, "phase##%d", i);
                     ImGui::PlotLines(str, li_hist_phase[i], HIST_DEPTH, 0, 0, -M_PI, M_PI, ImVec2(0.0f, 200.0f));
-                }
-                bool pause_l = li_hist_pause[i];
-                sprintf(str, "pause##%d", i);
-                ImGui::Checkbox(str, &pause_l);
-                ImGui::SameLine();
-                ImGui::Text("/");
-                li_hist_pause[i] = pause_l;
-                ImGui::SameLine();
-                {
-                    std::lock_guard<std::mutex> guard(li_hist_mutex);
                     ImGui::Text("values: %8.5f %8.5f rad", li_hist_mag[i][511], li_hist_phase[i][511]);
                 }
             }