better Hz/db formatting

src/core/Types.h

@@ -2,6 +2,8 @@
 
 #include <cstddef>
 #include <cstdint>
+#include <cstdio>
+#include <cmath>
 #include <complex>
 #include <string>
 #include <vector>
@@ -85,6 +87,28 @@ inline const char* inputFormatName(InputFormat f) {
     }
 }
 
+// ── Formatting helpers ───────────────────────────────────────────────────────
+
+// Format frequency into buf with fixed-width numeric field per unit range.
+inline int fmtFreq(char* buf, size_t sz, double freq) {
+    if (std::abs(freq) >= 1e6)
+        return std::snprintf(buf, sz, "% 10.6f MHz", freq / 1e6);
+    else if (std::abs(freq) >= 1e3)
+        return std::snprintf(buf, sz, "% 7.3f kHz", freq / 1e3);
+    else
+        return std::snprintf(buf, sz, "% 7.1f Hz", freq);
+}
+
+// Format "label: freq, dB" into buf for sidebar display (fixed-width freq + dB).
+inline int fmtFreqDB(char* buf, size_t sz, const char* label, double freq, float dB) {
+    if (std::abs(freq) >= 1e6)
+        return std::snprintf(buf, sz, "%s: % 10.6f MHz %6.1f dB", label, freq / 1e6, dB);
+    else if (std::abs(freq) >= 1e3)
+        return std::snprintf(buf, sz, "%s: % 7.3f kHz %6.1f dB", label, freq / 1e3, dB);
+    else
+        return std::snprintf(buf, sz, "%s:  % 7.1f Hz %6.1f dB", label, freq, dB);
+}
+
 // ── Spectrum data ────────────────────────────────────────────────────────────
 
 struct SpectrumLine {

src/ui/Application.cpp

@@ -460,13 +460,7 @@ void Application::render() {
 
             // Frequency label at top of waterfall
             char freqLabel[48];
-            double hf = cursors_.hover.freq;
+            fmtFreq(freqLabel, sizeof(freqLabel), cursors_.hover.freq);
-            if (std::abs(hf) >= 1e6)
-                std::snprintf(freqLabel, sizeof(freqLabel), "%.6f MHz", hf / 1e6);
-            else if (std::abs(hf) >= 1e3)
-                std::snprintf(freqLabel, sizeof(freqLabel), "%.3f kHz", hf / 1e3);
-            else
-                std::snprintf(freqLabel, sizeof(freqLabel), "%.1f Hz", hf);
 
             ImVec2 tSz = ImGui::CalcTextSize(freqLabel);
             float lx = std::min(hx + 4, wfPosX_ + wfSizeX_ - tSz.x - 4);
@@ -572,7 +566,8 @@ void Application::renderControlPanel() {
     if (ImGui::CollapsingHeader("FFT", ImGuiTreeNodeFlags_DefaultOpen)) {
         const char* sizeNames[] = {"256", "512", "1024", "2048", "4096",
                                    "8192", "16384", "32768", "65536"};
-        ImGui::SetNextItemWidth(-1);
+        float halfW = (ImGui::GetContentRegionAvail().x - ImGui::GetStyle().ItemSpacing.x) * 0.5f;
+        ImGui::SetNextItemWidth(halfW);
         if (ImGui::Combo("##fftsize", &fftSizeIdx_, sizeNames, kNumFFTSizes)) {
             settings_.fftSize = kFFTSizes[fftSizeIdx_];
             updateAnalyzerSettings();
@@ -580,9 +575,10 @@ void Application::renderControlPanel() {
         }
         if (ImGui::IsItemHovered()) ImGui::SetTooltip("FFT Size");
 
+        ImGui::SameLine();
         const char* winNames[] = {"Rectangular", "Hann", "Hamming", "Blackman",
                                   "Blackman-Harris", "Kaiser", "Flat Top"};
-        ImGui::SetNextItemWidth(-1);
+        ImGui::SetNextItemWidth(halfW);
         if (ImGui::Combo("##window", &windowIdx_, winNames,
                          static_cast<int>(WindowType::Count))) {
             settings_.window = static_cast<WindowType>(windowIdx_);
@@ -621,7 +617,7 @@ void Application::renderControlPanel() {
             ImVec2 rMax = ImGui::GetItemRectMax();
             float tx = rMin.x + ((rMax.x - rMin.x) - textSize.x) * 0.5f;
             float ty = rMin.y + ((rMax.y - rMin.y) - textSize.y) * 0.5f;
-            ImGui::GetForegroundDrawList()->AddText({tx, ty}, IM_COL32(255, 255, 255, 220), overlayText);
+            ImGui::GetWindowDrawList()->AddText({tx, ty}, IM_COL32(255, 255, 255, 220), overlayText);
             if (ImGui::IsItemHovered()) ImGui::SetTooltip("Overlap");
         }
     }
@@ -635,6 +631,7 @@ void Application::renderControlPanel() {
         if (ImGui::IsItemHovered()) ImGui::SetTooltip("dB Range (min / max)");
 
         ImGui::Checkbox("Peak Hold", &specDisplay_.peakHoldEnable);
+        if (ImGui::IsItemHovered()) ImGui::SetTooltip("Draws a \"maximum\" line in the spectrogram");
         if (specDisplay_.peakHoldEnable) {
             ImGui::SameLine();
             ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x
@@ -669,6 +666,7 @@ void Application::renderControlPanel() {
                 viewLo_ = 0.0f;
                 viewHi_ = 0.5f;
             }
+            if (ImGui::IsItemHovered()) ImGui::SetTooltip("Reset to 2x zoom");
         }
     }
 
@@ -829,12 +827,11 @@ void Application::renderControlPanel() {
     int pkCh2 = std::clamp(waterfallChannel_, 0, analyzer_.numSpectra() - 1);
     auto [peakBin, peakDB] = analyzer_.findPeak(pkCh2);
     double peakFreq = analyzer_.binToFreq(peakBin);
-    if (std::abs(peakFreq) >= 1e6)
+    {
-        ImGui::TextDisabled("Peak: %.6f MHz, %.1f dB", peakFreq / 1e6, peakDB);
+        char peakBuf[128];
-    else if (std::abs(peakFreq) >= 1e3)
+        fmtFreqDB(peakBuf, sizeof(peakBuf), "Peak", peakFreq, peakDB);
-        ImGui::TextDisabled("Peak: %.3f kHz, %.1f dB", peakFreq / 1e3, peakDB);
+        ImGui::TextDisabled("%s", peakBuf);
-    else
+    }
-        ImGui::TextDisabled("Peak: %.1f Hz, %.1f dB", peakFreq, peakDB);
 }
 
 void Application::renderSpectrumPanel() {

src/ui/Cursors.cpp

@@ -78,12 +78,7 @@ void Cursors::draw(const SpectrumDisplay& specDisplay,
 
     // Format a cursor label string.
     auto formatLabel = [](char* buf, size_t sz, const char* label, double freq, float dB) {
-        if (std::abs(freq) >= 1e6)
+        fmtFreqDB(buf, sz, label, freq, dB);
-            std::snprintf(buf, sz, "%s: %.6f MHz  %.1f dB", label, freq / 1e6, dB);
-        else if (std::abs(freq) >= 1e3)
-            std::snprintf(buf, sz, "%s: %.3f kHz  %.1f dB", label, freq / 1e3, dB);
-        else
-            std::snprintf(buf, sz, "%s: %.1f Hz  %.1f dB", label, freq, dB);
     };
 
     float aDB = avgDBA(), bDB = avgDBB();
@@ -124,12 +119,7 @@ void Cursors::draw(const SpectrumDisplay& specDisplay,
         double dFreq = cursorB.freq - cursorA.freq;
         float dDB = bDB - aDB;
         char val1[48], val2[48];
-        if (std::abs(dFreq) >= 1e6)
+        fmtFreq(val1, sizeof(val1), dFreq);
-            std::snprintf(val1, sizeof(val1), "%.6f MHz", dFreq / 1e6);
-        else if (std::abs(dFreq) >= 1e3)
-            std::snprintf(val1, sizeof(val1), "%.3f kHz", dFreq / 1e3);
-        else
-            std::snprintf(val1, sizeof(val1), "%.1f Hz", dFreq);
         std::snprintf(val2, sizeof(val2), "%.1f dB", dDB);
 
         ImVec2 labelSz = ImGui::CalcTextSize("dF = ");
@@ -138,7 +128,7 @@ void Cursors::draw(const SpectrumDisplay& specDisplay,
         float valW = std::max(v1Sz.x, v2Sz.x);
         float lineH = labelSz.y;
         float totalW = labelSz.x + valW;
-        float tx = posX + sizeX - totalW - 8;
+        float tx = posX + sizeX - totalW - 158;
         float ty = posY + 4;
         ImU32 col = IM_COL32(255, 200, 100, 255);
         float eqX = tx + labelSz.x;  // values start here (right of '= ')
@@ -158,12 +148,9 @@ void Cursors::drawPanel() {
             ImGui::TextDisabled("%s: --", label);
             return;
         }
-        if (std::abs(c.freq) >= 1e6)
+        char buf[128];
-            ImGui::Text("%s: %.6f MHz, %.1f dB", label, c.freq / 1e6, dispDB);
+        fmtFreqDB(buf, sizeof(buf), label, c.freq, dispDB);
-        else if (std::abs(c.freq) >= 1e3)
+        ImGui::Text("%s", buf);
-            ImGui::Text("%s: %.3f kHz, %.1f dB", label, c.freq / 1e3, dispDB);
-        else
-            ImGui::Text("%s: %.1f Hz, %.1f dB", label, c.freq, dispDB);
     };
 
     float aDB = avgDBA(), bDB = avgDBB();
@@ -173,21 +160,9 @@ void Cursors::drawPanel() {
     if (cursorA.active && cursorB.active) {
         double dF = cursorB.freq - cursorA.freq;
         float dA = bDB - aDB;
-        if (std::abs(dF) >= 1e6)
+        char dbuf[128];
-            ImGui::Text("D: %.6f MHz, %.1f dB", dF / 1e6, dA);
+        fmtFreqDB(dbuf, sizeof(dbuf), "D", dF, dA);
-        else if (std::abs(dF) >= 1e3)
+        ImGui::Text("%s", dbuf);
-            ImGui::Text("D: %.3f kHz, %.1f dB", dF / 1e3, dA);
-        else
-            ImGui::Text("D: %.1f Hz, %.1f dB", dF, dA);
-    }
-
-    if (hover.active) {
-        if (std::abs(hover.freq) >= 1e6)
-            ImGui::TextDisabled("%.6f MHz, %.1f dB", hover.freq / 1e6, hover.dB);
-        else if (std::abs(hover.freq) >= 1e3)
-            ImGui::TextDisabled("%.3f kHz, %.1f dB", hover.freq / 1e3, hover.dB);
-        else
-            ImGui::TextDisabled("%.1f Hz, %.1f dB", hover.freq, hover.dB);
     }
 
     // Averaging slider (logarithmic scale)

src/ui/Measurements.cpp

@@ -186,12 +186,11 @@ void Measurements::drawPanel() {
             ImU32 col = (i == 0) ? IM_COL32(255, 80, 80, 255)
                                  : IM_COL32(255, 140, 60, 255);
             ImGui::PushStyleColor(ImGuiCol_Text, col);
-            if (std::abs(p.freq) >= 1e6)
+            char plabel[4];
-                ImGui::Text("P%d: %.6f MHz, %.1f dB", i + 1, p.freq / 1e6, p.dB);
+            std::snprintf(plabel, sizeof(plabel), "P%d", i + 1);
-            else if (std::abs(p.freq) >= 1e3)
+            char pbuf[128];
-                ImGui::Text("P%d: %.3f kHz, %.1f dB", i + 1, p.freq / 1e3, p.dB);
+            fmtFreqDB(pbuf, sizeof(pbuf), plabel, p.freq, p.dB);
-            else
+            ImGui::Text("%s", pbuf);
-                ImGui::Text("P%d: %.1f Hz, %.1f dB", i + 1, p.freq, p.dB);
             ImGui::PopStyleColor();
         }
     }