improved formatting and positioning of cursor labels

src/core/Types.h

@@ -99,14 +99,33 @@ inline int fmtFreq(char* buf, size_t sz, double freq) {
         return std::snprintf(buf, sz, "% 7.1f Hz", freq);
 }
 
-// Format "label: freq, dB" into buf for sidebar display (fixed-width freq + dB).
+// Format "label: freq dB" into buf for sidebar display (fixed-width freq + dB).
+// If label is null or empty, omits the "label: " prefix.
 inline int fmtFreqDB(char* buf, size_t sz, const char* label, double freq, float dB) {
+    int off = 0;
+    if (label && label[0])
+        off = std::snprintf(buf, sz, "%s: ", label);
     if (std::abs(freq) >= 1e6)
-        return std::snprintf(buf, sz, "%s: % 10.6f MHz %6.1f dB", label, freq / 1e6, dB);
+        off += std::snprintf(buf + off, sz - off, "% 10.6f MHz %6.1f dB", 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);
+        off += std::snprintf(buf + off, sz - off, "% 7.3f kHz %6.1f dB", freq / 1e3, dB);
     else
-        return std::snprintf(buf, sz, "%s:  % 7.1f Hz %6.1f dB", label, freq, dB);
+        off += std::snprintf(buf + off, sz - off, " % 7.1f Hz %6.1f dB", freq, dB);
+    return off;
+}
+
+// Format "label: freq, time" into buf for sidebar/overlay display (fixed-width).
+inline int fmtFreqTime(char* buf, size_t sz, const char* label, double freq, float seconds) {
+    int off = 0;
+    if (label && label[0])
+        off = std::snprintf(buf, sz, "%s: ", label);
+    if (std::abs(freq) >= 1e6)
+        off += std::snprintf(buf + off, sz - off, "% 10.6f MHz %7.2f s", freq / 1e6, seconds);
+    else if (std::abs(freq) >= 1e3)
+        off += std::snprintf(buf + off, sz - off, "% 7.3f kHz %7.2f s", freq / 1e3, seconds);
+    else
+        off += std::snprintf(buf + off, sz - off, " % 7.1f Hz %7.2f s", freq, seconds);
+    return off;
 }
 
 // ── Spectrum data ────────────────────────────────────────────────────────────

src/ui/Application.cpp

@@ -478,48 +478,21 @@ void Application::render() {
                 double binCenterFreq = fMin + (static_cast<double>(cursors_.hover.bin) + 0.5)
                                        / bins * (fMax - fMin);
 
-                // Fixed-width frequency string to prevent jumping
+                char hoverBuf[128];
-                char freqBuf[48];
-                if (std::abs(binCenterFreq) >= 1e6)
-                    std::snprintf(freqBuf, sizeof(freqBuf), "%12.6f MHz", binCenterFreq / 1e6);
-                else if (std::abs(binCenterFreq) >= 1e3)
-                    std::snprintf(freqBuf, sizeof(freqBuf), "%9.3f kHz", binCenterFreq / 1e3);
-                else
-                    std::snprintf(freqBuf, sizeof(freqBuf), "%7.1f Hz", binCenterFreq);
-
-                char valBuf[48];
                 if (hoverPanel_ == HoverPanel::Spectrum) {
-                    std::snprintf(valBuf, sizeof(valBuf), "%7.1f dB", cursors_.hover.dB);
+                    fmtFreqDB(hoverBuf, sizeof(hoverBuf), "", binCenterFreq, cursors_.hover.dB);
                 } else if (hoverPanel_ == HoverPanel::Waterfall) {
-                    if (hoverWfTimeOffset_ >= 10.0f)
+                    fmtFreqTime(hoverBuf, sizeof(hoverBuf), "", binCenterFreq, -hoverWfTimeOffset_);
-                        std::snprintf(valBuf, sizeof(valBuf), "%7.1f s", -hoverWfTimeOffset_);
-                    else if (hoverWfTimeOffset_ >= 1.0f)
-                        std::snprintf(valBuf, sizeof(valBuf), "%7.2f s", -hoverWfTimeOffset_);
-                    else
-                        std::snprintf(valBuf, sizeof(valBuf), "%5.0f ms", -hoverWfTimeOffset_ * 1000.0f);
                 } else {
-                    valBuf[0] = '\0';
+                    fmtFreq(hoverBuf, sizeof(hoverBuf), binCenterFreq);
                 }
 
-                // Draw as a single right-aligned line, fixed-width value column
+                // Right-align the text
                 ImU32 hoverTextCol = IM_COL32(100, 230, 130, 240);
                 float rightEdge = specPosX_ + specSizeX_ - 8;
                 float hy2 = specPosY_ + 4;
-
+                ImVec2 hSz = ImGui::CalcTextSize(hoverBuf);
-                // Use a fixed-width reference for the value column to prevent jumping
+                dlp->AddText({rightEdge - hSz.x, hy2}, hoverTextCol, hoverBuf);
-                ImVec2 refSz = ImGui::CalcTextSize("-000.0 dB");
-                ImVec2 freqSz = ImGui::CalcTextSize(freqBuf);
-                float sepW = ImGui::CalcTextSize("  ").x;
-                float valColX = rightEdge - refSz.x;
-                float freqX = valColX - sepW - freqSz.x;
-
-                if (valBuf[0]) {
-                    ImVec2 valSz = ImGui::CalcTextSize(valBuf);
-                    dlp->AddText({freqX, hy2}, hoverTextCol, freqBuf);
-                    dlp->AddText({rightEdge - valSz.x, hy2}, hoverTextCol, valBuf);
-                } else {
-                    dlp->AddText({rightEdge - freqSz.x, hy2}, hoverTextCol, freqBuf);
-                }
             }
         }
     }

src/ui/Cursors.cpp

@@ -97,7 +97,8 @@ void Cursors::draw(const SpectrumDisplay& specDisplay,
         formatLabel(buf, sizeof(buf), label, c.freq, dispDB);
         ImVec2 sz = ImGui::CalcTextSize(buf);
         float lineH = ImGui::GetTextLineHeight();
-        float ty = posY + 4 + row * (lineH + 4);
+        // draw starting from the second line -- on the first line, we have cursor data
+        float ty = posY + 4 + (row + 1) * (lineH + 4);
 
         // Place right of cursor line; flip left if it would overflow.
         float tx;
@@ -118,25 +119,15 @@ void Cursors::draw(const SpectrumDisplay& specDisplay,
     if (showDelta && cursorA.active && cursorB.active) {
         double dFreq = cursorB.freq - cursorA.freq;
         float dDB = bDB - aDB;
-        char val1[48], val2[48];
+        char deltaBuf[128];
-        fmtFreq(val1, sizeof(val1), dFreq);
+        fmtFreqDB(deltaBuf, sizeof(deltaBuf), "D", dFreq, dDB);
-        std::snprintf(val2, sizeof(val2), "%.1f dB", dDB);
 
-        ImVec2 labelSz = ImGui::CalcTextSize("dF = ");
+        ImVec2 dSz = ImGui::CalcTextSize(deltaBuf);
-        ImVec2 v1Sz = ImGui::CalcTextSize(val1);
+        float tx = posX + sizeX - dSz.x - 178;
-        ImVec2 v2Sz = ImGui::CalcTextSize(val2);
+        float lineH = ImGui::GetTextLineHeight();
-        float valW = std::max(v1Sz.x, v2Sz.x);
-        float lineH = labelSz.y;
-        float totalW = labelSz.x + valW;
-        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 '= ')
+        dl->AddText({tx, ty}, col, deltaBuf);
-
-        dl->AddText({tx, ty}, col, "dF =");
-        dl->AddText({eqX + valW - v1Sz.x, ty}, col, val1);
-        dl->AddText({tx, ty + lineH + 2}, col, "dA =");
-        dl->AddText({eqX + valW - v2Sz.x, ty + lineH + 2}, col, val2);
     }
 
     // (Hover cursor line is drawn cross-panel by Application.)