Added SNR meter

core/src/gui/main_window.cpp

@@ -32,6 +32,7 @@
 #include <gui/dialogs/loading_screen.h>
 #include <options.h>
 #include <gui/colormaps.h>
+#include <gui/widgets/snr_meter.h>
 
 int fftSize = 8192 * 8;
 
@@ -103,6 +104,8 @@ bool centerTuning = false;
 dsp::stream<dsp::complex_t> dummyStream;
 bool demoWindow = false;
 
+float testSNR = 50;
+
 void windowInit() {
     LoadingScreen::show("Initializing UI");
     gui::waterfall.init();
@@ -515,6 +518,13 @@ void drawWindow() {
 
     ImGui::SameLine();
 
+    ImGui::SetCursorPosX(ImGui::GetWindowSize().x - 387);
+    ImGui::SetCursorPosY(ImGui::GetCursorPosY() + 5);
+    ImGui::SetNextItemWidth(300);
+    ImGui::SNRMeter((vfo != NULL) ? gui::waterfall.selectedVFOSNR : 0);
+
+    ImGui::SameLine();
+
     // Logo button
     ImGui::SetCursorPosX(ImGui::GetWindowSize().x - 48);
     ImGui::SetCursorPosY(10);
@@ -604,6 +614,8 @@ void drawWindow() {
                 firstMenuRender = true;
             }
 
+            ImGui::SliderFloat("Testing SNR meter", &testSNR, 0, 100);
+
             ImGui::Spacing();
         }
 

core/src/gui/widgets/snr_meter.cpp

@@ -0,0 +1,43 @@
+#include <gui/widgets/volume_meter.h>
+#include <algorithm>
+
+#ifndef IMGUI_DEFINE_MATH_OPERATORS
+#define IMGUI_DEFINE_MATH_OPERATORS
+#endif
+#include <imgui/imgui_internal.h>
+
+namespace ImGui {
+    void SNRMeter(float val, const ImVec2& size_arg = ImVec2(0, 0)) {
+        ImGuiWindow* window = GetCurrentWindow();
+        ImGuiStyle& style = GImGui->Style;
+
+        float pad = style.FramePadding.y;
+
+        ImVec2 min = window->DC.CursorPos;
+        ImVec2 size = CalcItemSize(size_arg, CalcItemWidth(), 26);
+        ImRect bb(min, min + size);
+
+        float lineHeight = size.y;
+
+        ItemSize(size, style.FramePadding.y);
+        if (!ItemAdd(bb, 0)) {
+            return;
+        }
+
+        val = std::clamp<float>(val, 0, 100);
+        float ratio = size.x / 90;
+        float it = size.x / 9;
+        char buf[32];
+
+        window->DrawList->AddRectFilled(min + ImVec2(0, 1), min + ImVec2(roundf((float)val * ratio), 10), IM_COL32(0, 136, 255, 255));
+        window->DrawList->AddLine(min, min + ImVec2(0, 9), IM_COL32(255, 255, 255, 255));
+        window->DrawList->AddLine(min + ImVec2(0, 9), min + ImVec2(size.x + 1, 9), IM_COL32(255, 255, 255, 255));
+
+        for (int i = 0; i < 10; i++) {
+            window->DrawList->AddLine(min + ImVec2(roundf((float)i * it), 9), min + ImVec2(roundf((float)i * it), 14), IM_COL32(255, 255, 255, 255));
+            sprintf(buf, "%d", i * 10);
+            ImVec2 sz = ImGui::CalcTextSize(buf);
+            window->DrawList->AddText(min + ImVec2(roundf(((float)i * it) - (sz.x/2.0)) + 1, 16), IM_COL32(255, 255, 255, 255), buf);
+        }
+    }
+}

core/src/gui/widgets/snr_meter.h

@@ -0,0 +1,6 @@
+#pragma once
+#include <imgui/imgui.h>
+
+namespace ImGui {
+    void SNRMeter(float val, const ImVec2& size_arg = ImVec2(0, 0));
+}

core/src/gui/widgets/waterfall.cpp

@@ -288,10 +288,6 @@ namespace ImGui {
             // Next, check if a VFO was selected
             if (!targetFound) {
                 for (auto const& [name, _vfo] : vfos) {
-                    if (name == selectedVFO) {
-                        continue;
-                    }
-
                     // If another VFO is selected, select it and cancel out
                     if (IS_IN_AREA(mousePos, _vfo->rectMin, _vfo->rectMax) || IS_IN_AREA(mousePos, _vfo->wfRectMin, _vfo->wfRectMax)) {
                         selectedVFO = name;
@@ -436,6 +432,16 @@ namespace ImGui {
                         printAndScale(_vfo->bandwidth, buf);
                         ImGui::Text("Bandwidth: %sHz", buf);
                         ImGui::Text("Bandwidth Locked: %s", _vfo->bandwidthLocked ? "Yes" : "No");
+
+                        float strength, snr;
+                        if (calculateVFOSignalInfo(_vfo, strength, snr)) {
+                            ImGui::Text("Strength: %0.1fdBFS", strength);
+                            ImGui::Text("SNR: %0.1fdB", snr);
+                        }
+                        else {
+                            ImGui::Text("Strength: ---.-dBFS");
+                            ImGui::Text("SNR: ---.-dB");
+                        }
                     }
 
                     ImGui::EndTooltip();
@@ -445,6 +451,50 @@ namespace ImGui {
         }      
     }
 
+    bool WaterFall::calculateVFOSignalInfo(WaterfallVFO* _vfo, float& strength, float& snr) {
+        if (rawFFTs == NULL || fftLines <= 0) { return false; }
+
+        // Calculate FFT index data
+        double vfoMinSizeFreq = _vfo->centerOffset - _vfo->bandwidth;
+        double vfoMinFreq = _vfo->centerOffset - (_vfo->bandwidth/2.0);
+        double vfoMaxFreq = _vfo->centerOffset + (_vfo->bandwidth/2.0);
+        double vfoMaxSizeFreq = _vfo->centerOffset + _vfo->bandwidth;
+        int vfoMinSideOffset = std::clamp<int>(((vfoMinSizeFreq / (wholeBandwidth/2.0)) * (double)(rawFFTSize/2)) + (rawFFTSize/2), 0, rawFFTSize);
+        int vfoMinOffset = std::clamp<int>(((vfoMinFreq / (wholeBandwidth/2.0)) * (double)(rawFFTSize/2)) + (rawFFTSize/2), 0, rawFFTSize);
+        int vfoMaxOffset = std::clamp<int>(((vfoMaxFreq / (wholeBandwidth/2.0)) * (double)(rawFFTSize/2)) + (rawFFTSize/2), 0, rawFFTSize);
+        int vfoMaxSideOffset = std::clamp<int>(((vfoMaxSizeFreq / (wholeBandwidth/2.0)) * (double)(rawFFTSize/2)) + (rawFFTSize/2), 0, rawFFTSize);
+
+        float* fftLine = &rawFFTs[currentFFTLine * rawFFTSize];
+
+        double avg = 0;
+        float max = -INFINITY;
+        int avgCount = 0;
+
+        // Calculate Left average
+        for (int i = vfoMinSideOffset; i < vfoMinOffset; i++) {
+            avg += fftLine[i];
+            avgCount++;
+        }
+
+        // Calculate Right average
+        for (int i = vfoMaxOffset + 1; i < vfoMaxSideOffset; i++) {
+            avg += fftLine[i];
+            avgCount++;
+        }
+
+        avg /= (double)(avgCount);
+
+        // Calculate max
+        for (int i = vfoMinOffset; i <= vfoMaxOffset; i++) {
+            if (fftLine[i] > max) { max = fftLine[i]; }
+        }
+
+        strength = max;
+        snr = max - avg;
+
+        return true;
+    }
+
     void WaterFall::setFastFFT(bool fastFFT) {
         std::lock_guard<std::mutex> lck(buf_mtx);
         _fastFFT = fastFFT;
@@ -748,6 +798,11 @@ namespace ImGui {
             doZoom(drawDataStart, drawDataSize, dataWidth, rawFFTs, latestFFT, _fastFFT);
             fftLines = 1;
         }
+
+        if (selectedVFO != "" && vfos.size() > 0) {
+            float dummy;
+            calculateVFOSignalInfo(vfos[selectedVFO], dummy, selectedVFOSNR);
+        }
         
         buf_mtx.unlock();
     }

core/src/gui/widgets/waterfall.h

@@ -133,6 +133,8 @@ namespace ImGui {
         bool mouseInFFT = false;
         bool mouseInWaterfall = false;
 
+        float selectedVFOSNR = NAN;
+
         std::map<std::string, WaterfallVFO*> vfos;
         std::string selectedVFO = "";
         bool selectedVFOChanged = false;
@@ -162,6 +164,7 @@ namespace ImGui {
         void updateWaterfallFb();
         void updateWaterfallTexture();
         void updateAllVFOs();
+        bool calculateVFOSignalInfo(WaterfallVFO* vfo, float& strength, float& snr);
 
         bool waterfallUpdate = false;