settings, toggles, and more

README.md

@@ -51,9 +51,7 @@ Capture-to-display latency measures under 8ms. When tested at 120fps, measured l
 
 Installable Prism packages also provide `prism-tui`, a native terminal frontend
 for the shared C++ capture and analysis engine. It shows a responsive spectrum,
-stereo VU meters, and momentary, short-term, and integrated LUFS readings. The
-dashboard uses a 4096-point FFT by default and automatically switches between
-stacked and column layouts as the terminal is resized.
+stereo VU meters, and momentary, short-term, and integrated LUFS readings.
 
 ```bash
 prism-tui                    # Capture the default system output
@@ -63,13 +61,11 @@ prism-tui --help
 prism-tui --version
 ```
 
-Press Tab or Shift-Tab to focus a panel, Enter to expand or restore it, and `l`
-to cycle automatic, stacked, and column layouts. Number keys `1` and `2` focus
-Spectrum and Levels. Press `r` to reset the analyzers and integrated loudness,
-or `q`, Escape, or Ctrl-C to quit. Interactive mode requires a terminal of at
-least 44 by 12 cells. Quote a device ID if it contains spaces. Successful help,
-version, listing, and interactive exits return `0`; usage errors return `2`;
-capture and runtime failures return `1`.
+Press `r` to reset the analyzers and integrated loudness, or `q`, Escape, or
+Ctrl-C to quit. Interactive mode requires a terminal of at least 44 by 12 cells.
+Quote a device ID if it contains spaces. Successful help, version, listing, and
+interactive exits return `0`; usage errors return `2`; capture and runtime
+failures return `1`.
 
 The v0 TUI captures system output only. Microphone/device-input capture, Prism
 profiles and themes, file/stdin analysis, and the other visualizers remain GUI

native/src/oscilloscope.cpp

@@ -12,6 +12,7 @@ Oscilloscope::Oscilloscope()
     , lastFilterPitch_(200.0f)
     , lastTrigger_(0)
     , smoothedPitch_(200.0f)
+    , latestDetectedPitch_(0.0f)
     , pitchSamplesProcessed_(0) {
 
     // Initialize circular buffers
@@ -144,6 +145,10 @@ OscilloscopeResult Oscilloscope::process() {
     result.detectedPitch = smoothedPitch_;
 
     if (!pitchLock_) {
+        const size_t samples = static_cast<size_t>(displaySamples_);
+        result.triggerIndex = static_cast<float>(
+            (writePos_ + OSCILLOSCOPE_BUFFER_SIZE - samples) %
+            OSCILLOSCOPE_BUFFER_SIZE);
         return result;
     }
 
@@ -172,6 +177,7 @@ OscilloscopeResult Oscilloscope::process() {
 
     float newPitch = DSP::detectPitchFFT(recentSamples.data(), 2048, sampleRate_, 40.0f, 1000.0f);
     if (newPitch > 0.0f) {
+        latestDetectedPitch_ = newPitch;
         pitchSamplesProcessed_++;
 
         // Adaptive smoothing: fast convergence initially, then conservative
@@ -307,6 +313,7 @@ void Oscilloscope::reset() {
     writePos_ = 0;
     lastTrigger_ = 0.0f;
     smoothedPitch_ = 200.0f;
+    latestDetectedPitch_ = 0.0f;
     lastFilterPitch_ = 200.0f;
     pitchSamplesProcessed_ = 0;  // Reset warmup counter for fast convergence on next use
 

native/src/oscilloscope.h

@@ -36,6 +36,10 @@ public:
     // Get current write position
     size_t getWritePos() const { return writePos_; }
 
+    // Latest unsmoothed detector result. The stable detectedPitch returned by
+    // process() remains the value used for pitch-locked triggering.
+    float getLatestDetectedPitch() const { return latestDetectedPitch_; }
+
     // Get samples from circular buffer (for rendering)
     void getSamples(float* output, size_t startPos, size_t count) const;
 
@@ -75,6 +79,7 @@ private:
 
     float lastTrigger_;
     float smoothedPitch_;
+    float latestDetectedPitch_;
     int pitchSamplesProcessed_;  // Track samples for adaptive smoothing
 
     // Internal helpers

tui/CMakeLists.txt

@@ -33,7 +33,13 @@ add_library(prism_tui_analysis STATIC
     src/cli.cpp
     src/dashboard_layout.cpp
     src/display_model.cpp
+    src/scope_plot_model.cpp
+    src/spectrum_peak_model.cpp
+    src/tui_settings.cpp
     ${PRISM_NATIVE_DIR}/spectrum.cpp
+    ${PRISM_NATIVE_DIR}/oscilloscope.cpp
+    ${PRISM_NATIVE_DIR}/vectorscope.cpp
+    ${PRISM_NATIVE_DIR}/multiband.cpp
     ${PRISM_NATIVE_DIR}/vumeter.cpp
     ${PRISM_NATIVE_DIR}/lufsmeter.cpp
     ${PRISM_NATIVE_DIR}/dsp_utils.cpp)

tui/src/analysis_pipeline.cpp

@@ -1,15 +1,39 @@
 #include "analysis_pipeline.h"
 
 #include <algorithm>
+#include <cmath>
 
 namespace Prism::Tui {
+namespace {
+
+int normalizedOscilloscopeDisplaySamples(float sampleRate) {
+    constexpr int baseSamples = 2048;
+    constexpr float baseRateMin = 44100.0f;
+    constexpr float baseRateMax = 48000.0f;
+    float samples = static_cast<float>(baseSamples);
+    if (sampleRate > 0.0f && sampleRate < baseRateMin) {
+        samples *= sampleRate / baseRateMin;
+    } else if (sampleRate > baseRateMax) {
+        samples *= sampleRate / baseRateMax;
+    }
+    return std::clamp(
+        static_cast<int>(std::lround(samples)),
+        64,
+        static_cast<int>(Visualizer::OSCILLOSCOPE_BUFFER_SIZE - 1));
+}
+
+}  // namespace
 
 AnalysisPipeline::AnalysisPipeline(float sampleRate, size_t fftSize)
-    : spectrum_(fftSize) {
+    : spectrum_(fftSize), sampleRate_(sampleRate), fftSize_(fftSize) {
     spectrum_.setSampleRate(sampleRate);
     spectrum_.setSmoothing(0.9f);
     vu_.setSampleRate(sampleRate);
     lufs_.setSampleRate(sampleRate);
+    oscilloscope_.setSampleRate(sampleRate);
+    oscilloscope_.setPitchLock(true);
+    oscilloscope_.setDisplaySamples(normalizedOscilloscopeDisplaySamples(sampleRate));
+    vectorscope_.setSampleRate(sampleRate);
 }
 
 void AnalysisPipeline::process(const Prism::Capture::AudioChunk& chunk) {
@@ -17,23 +41,96 @@ void AnalysisPipeline::process(const Prism::Capture::AudioChunk& chunk) {
     if (count == 0) {
         return;
     }
-    spectrum_.pushStereoSamples(chunk.left.data(), chunk.right.data(), count);
-    vu_.pushSamples(chunk.left.data(), chunk.right.data(), count);
-    lufs_.pushSamples(chunk.left.data(), chunk.right.data(), count);
+    const float* left = chunk.left.data();
+    const float* right = chunk.right.data();
+    if (inputGainLinear_ != 1.0f) {
+        trimmedLeftScratch_.resize(count);
+        trimmedRightScratch_.resize(count);
+        for (size_t index = 0; index < count; ++index) {
+            trimmedLeftScratch_[index] = chunk.left[index] * inputGainLinear_;
+            trimmedRightScratch_[index] = chunk.right[index] * inputGainLinear_;
+        }
+        left = trimmedLeftScratch_.data();
+        right = trimmedRightScratch_.data();
+    }
+    spectrum_.pushStereoSamples(left, right, count);
+    vu_.pushSamples(left, right, count);
+    lufs_.pushSamples(left, right, count);
+    monoScratch_.resize(count);
+    for (size_t index = 0; index < count; ++index) {
+        monoScratch_[index] = (left[index] + right[index]) * 0.5f;
+    }
+    oscilloscope_.pushSamples(monoScratch_.data(), count);
+    vectorscope_.pushMultibandSamples(left, right, count);
 }
 
 AnalysisFrame AnalysisPipeline::snapshot() {
-    return {
-        spectrum_.getChannelMaxMagnitudes(),
-        vu_.getSnapshot(),
-        lufs_.getSnapshot(),
-    };
+    AnalysisFrame frame;
+    frame.magnitudes = spectrum_.getChannelMaxMagnitudes();
+    frame.spectrumPeak = spectrumPeakTracker_.select(
+        frame.magnitudes, sampleRate_, fftSize_, spectrumTiltDbPerOctave_);
+    frame.vu = vu_.getSnapshot();
+    frame.lufs = lufs_.getSnapshot();
+
+    const auto oscilloscopeResult = oscilloscope_.process();
+    const size_t oscilloscopeSamples = static_cast<size_t>(
+        std::max(0, oscilloscopeResult.samplesToShow));
+    frame.oscilloscope.samples.resize(oscilloscopeSamples);
+    if (!frame.oscilloscope.samples.empty()) {
+        oscilloscope_.getSamplesInterpolated(
+            frame.oscilloscope.samples.data(),
+            oscilloscopeResult.triggerIndex,
+            frame.oscilloscope.samples.size());
+        frame.oscilloscope.signalPresent = std::any_of(
+            frame.oscilloscope.samples.begin(),
+            frame.oscilloscope.samples.end(),
+            [](float sample) { return std::isfinite(sample) && std::abs(sample) > 0.001f; });
+    }
+    const float latestPitch = oscilloscope_.getLatestDetectedPitch();
+    if (std::isfinite(latestPitch) && latestPitch > 0.0f) {
+        constexpr float previousWeight = 0.6f;
+        displayPitch_ = displayPitch_ > 0.0f
+            ? displayPitch_ * previousWeight + latestPitch * (1.0f - previousWeight)
+            : latestPitch;
+    }
+    frame.oscilloscope.detectedPitch = displayPitch_;
+
+    frame.vectorscope.multibandPoints.resize(
+        kVectorscopeDisplayPoints * Visualizer::MULTIBAND_POINT_STRIDE);
+    frame.vectorscope.pointCount = vectorscope_.getMultibandPoints(
+        frame.vectorscope.multibandPoints.data(),
+        kVectorscopeDisplayPoints);
+    frame.vectorscope.multibandPoints.resize(
+        frame.vectorscope.pointCount * Visualizer::MULTIBAND_POINT_STRIDE);
+    return frame;
 }
 
 void AnalysisPipeline::reset() {
     spectrum_.reset();
     vu_.reset();
     lufs_.reset();
+    oscilloscope_.reset();
+    vectorscope_.reset();
+    spectrumPeakTracker_.reset();
+    monoScratch_.clear();
+    trimmedLeftScratch_.clear();
+    trimmedRightScratch_.clear();
+    displayPitch_ = 0.0f;
+}
+
+void AnalysisPipeline::setInputTrimDb(float db) {
+    const float normalized = std::clamp(
+        std::isfinite(db) ? db : 0.0f, -12.0f, 12.0f);
+    inputGainLinear_ = std::pow(10.0f, normalized / 20.0f);
+}
+
+void AnalysisPipeline::setSpectrumTilt(float dbPerOctave) {
+    spectrumTiltDbPerOctave_ = std::clamp(
+        std::isfinite(dbPerOctave) ? dbPerOctave : 2.0f, -2.0f, 8.0f);
+}
+
+void AnalysisPipeline::setOscilloscopePitchLock(bool enabled) {
+    oscilloscope_.setPitchLock(enabled);
 }
 
 size_t drainCapture(Prism::Capture::SystemAudioCapture& capture,

tui/src/analysis_pipeline.h

@@ -1,20 +1,39 @@
 #pragma once
 
 #include "lufsmeter.h"
+#include "oscilloscope.h"
 #include "spectrum.h"
+#include "spectrum_peak_model.h"
 #include "system_audio_capture.h"
+#include "vectorscope.h"
 #include "vumeter.h"
 
 #include <vector>
+#include <optional>
 
 namespace Prism::Tui {
 
 constexpr size_t kDefaultFftSize = 4096;
+constexpr size_t kVectorscopeDisplayPoints = 4096;
+
+struct OscilloscopeFrame {
+    std::vector<float> samples;
+    float detectedPitch = 0.0f;
+    bool signalPresent = false;
+};
+
+struct VectorscopeFrame {
+    std::vector<float> multibandPoints;
+    size_t pointCount = 0;
+};
 
 struct AnalysisFrame {
     std::vector<float> magnitudes;
+    std::optional<SpectrumPeakInfo> spectrumPeak;
     Visualizer::VUMeterSnapshot vu{};
     Visualizer::LUFSMeterSnapshot lufs{};
+    OscilloscopeFrame oscilloscope;
+    VectorscopeFrame vectorscope;
 };
 
 class AnalysisPipeline {
@@ -24,11 +43,25 @@ public:
     void process(const Prism::Capture::AudioChunk& chunk);
     AnalysisFrame snapshot();
     void reset();
+    void setInputTrimDb(float db);
+    void setSpectrumTilt(float dbPerOctave);
+    void setOscilloscopePitchLock(bool enabled);
 
 private:
     Visualizer::Spectrum spectrum_;
     Visualizer::VUMeterAnalyzer vu_;
     Visualizer::LUFSMeterAnalyzer lufs_;
+    Visualizer::Oscilloscope oscilloscope_;
+    Visualizer::Vectorscope vectorscope_;
+    SpectrumPeakTracker spectrumPeakTracker_;
+    std::vector<float> monoScratch_;
+    std::vector<float> trimmedLeftScratch_;
+    std::vector<float> trimmedRightScratch_;
+    float sampleRate_ = 48000.0f;
+    size_t fftSize_ = kDefaultFftSize;
+    float inputGainLinear_ = 1.0f;
+    float spectrumTiltDbPerOctave_ = 2.0f;
+    float displayPitch_ = 0.0f;
 };
 
 size_t drainCapture(Prism::Capture::SystemAudioCapture& capture,

tui/src/cli.cpp

@@ -60,8 +60,10 @@ std::string usageText() {
         "Controls:\n"
         "  Tab / Shift-Tab   Focus the next or previous panel.\n"
         "  Enter             Expand the focused panel or restore the dashboard.\n"
+        "  s                 Open settings for the focused scope.\n"
         "  l                 Cycle automatic, stacked, and column layouts.\n"
-        "  1 / 2             Focus Spectrum or Levels.\n"
+        "  v                 Cycle vectorscope display modes.\n"
+        "  1 / 2 / 3 / 4     Focus Spectrum, Oscilloscope, Vectorscope, or Levels.\n"
         "  r                 Reset analyzers and integrated loudness.\n"
         "  q / Esc / Ctrl-C  Quit.\n";
 }

tui/src/dashboard_layout.cpp

@@ -16,6 +16,10 @@ MinimumSize panelMinimumSize(PanelId panel) {
     switch (panel) {
         case PanelId::Spectrum:
             return {30, 5};
+        case PanelId::Oscilloscope:
+            return {30, 5};
+        case PanelId::Vectorscope:
+            return {30, 8};
         case PanelId::Levels:
             return {30, 5};
     }
@@ -134,13 +138,15 @@ void resolveNode(const LayoutNode& node,
 
 LayoutPreset resolvePreset(LayoutPreset requested, int width, int height) {
     constexpr int minimumColumnsWidth = 72;
-    if (requested == LayoutPreset::Columns && width < minimumColumnsWidth) {
+    constexpr int minimumColumnsHeight = 18;
+    if (requested == LayoutPreset::Columns &&
+        (width < minimumColumnsWidth || height < minimumColumnsHeight)) {
         return LayoutPreset::Stacked;
     }
     if (requested != LayoutPreset::Automatic) {
         return requested;
     }
-    return width >= 96 && height >= 28
+    return width >= minimumColumnsWidth && height >= minimumColumnsHeight
         ? LayoutPreset::Columns
         : LayoutPreset::Stacked;
 }
@@ -148,8 +154,14 @@ LayoutPreset resolvePreset(LayoutPreset requested, int width, int height) {
 LayoutNode makeRoot(LayoutPreset preset) {
     if (preset == LayoutPreset::Columns) {
         return LayoutNode::split(SplitAxis::Columns, {
-            LayoutNode::leaf(PanelId::Spectrum, 4),
-            LayoutNode::leaf(PanelId::Levels, 1),
+            LayoutNode::split(SplitAxis::Rows, {
+                LayoutNode::leaf(PanelId::Spectrum, 3),
+                LayoutNode::leaf(PanelId::Oscilloscope, 2),
+            }, 3),
+            LayoutNode::split(SplitAxis::Rows, {
+                LayoutNode::leaf(PanelId::Vectorscope, 1),
+                LayoutNode::leaf(PanelId::Levels, 1),
+            }, 1),
         });
     }
     return LayoutNode::split(SplitAxis::Rows, {
@@ -223,19 +235,50 @@ std::string layoutPresetName(LayoutPreset preset) {
 }
 
 std::vector<PanelId> panelOrder() {
-    return {PanelId::Spectrum, PanelId::Levels};
+    return {
+        PanelId::Spectrum,
+        PanelId::Oscilloscope,
+        PanelId::Vectorscope,
+        PanelId::Levels,
+    };
 }
 
 PanelId nextPanel(PanelId panel, bool reverse) {
-    const auto panels = panelOrder();
+    return nextPanel(panel, panelOrder(), reverse);
+}
+
+PanelId nextPanel(PanelId panel,
+                  const std::vector<PanelId>& panels,
+                  bool reverse) {
+    if (panels.empty()) {
+        return panel;
+    }
     const auto found = std::find(panels.begin(), panels.end(), panel);
-    const size_t index = found == panels.end()
-        ? 0
-        : static_cast<size_t>(std::distance(panels.begin(), found));
+    if (found == panels.end()) {
+        return reverse ? panels.back() : panels.front();
+    }
+    const size_t index = static_cast<size_t>(std::distance(panels.begin(), found));
     if (reverse) {
         return panels[(index + panels.size() - 1) % panels.size()];
     }
     return panels[(index + 1) % panels.size()];
 }
 
+std::vector<PanelId> visiblePanelOrder(const DashboardLayout& layout) {
+    std::vector<PanelId> result;
+    for (const auto panel : panelOrder()) {
+        if (layoutContainsPanel(layout, panel)) {
+            result.push_back(panel);
+        }
+    }
+    return result;
+}
+
+bool layoutContainsPanel(const DashboardLayout& layout, PanelId panel) {
+    return std::any_of(
+        layout.panels.begin(),
+        layout.panels.end(),
+        [panel](const PanelRect& rect) { return rect.panel == panel; });
+}
+
 }  // namespace Prism::Tui

tui/src/dashboard_layout.h

@@ -8,6 +8,8 @@ namespace Prism::Tui {
 
 enum class PanelId {
     Spectrum,
+    Oscilloscope,
+    Vectorscope,
     Levels,
 };
 
@@ -62,5 +64,10 @@ LayoutPreset nextLayoutPreset(LayoutPreset preset);
 std::string layoutPresetName(LayoutPreset preset);
 std::vector<PanelId> panelOrder();
 PanelId nextPanel(PanelId panel, bool reverse = false);
+PanelId nextPanel(PanelId panel,
+                  const std::vector<PanelId>& panels,
+                  bool reverse = false);
+std::vector<PanelId> visiblePanelOrder(const DashboardLayout& layout);
+bool layoutContainsPanel(const DashboardLayout& layout, PanelId panel);
 
 }  // namespace Prism::Tui

tui/src/scope_plot_model.cpp

@@ -0,0 +1,230 @@
+#include "scope_plot_model.h"
+
+#include "multiband.h"
+
+#include <algorithm>
+#include <cmath>
+
+namespace Prism::Tui {
+namespace {
+
+constexpr float kInverseSqrtTwo = 0.7071067811865475f;
+
+bool isUnipolar(VectorscopeMode mode) {
+    return mode == VectorscopeMode::PolarUnipolar ||
+        mode == VectorscopeMode::LinearUnipolar;
+}
+
+bool isPolar(VectorscopeMode mode) {
+    return mode == VectorscopeMode::PolarUnipolar ||
+        mode == VectorscopeMode::PolarBipolar;
+}
+
+bool transformVectorscopePoint(float left,
+                               float right,
+                               VectorscopeMode mode,
+                               float& x,
+                               float& y) {
+    if (mode == VectorscopeMode::Lissajous) {
+        x = right;
+        y = left;
+        return true;
+    }
+
+    const float mid = (left + right) * kInverseSqrtTwo;
+    const float side = (right - left) * kInverseSqrtTwo;
+    if (isUnipolar(mode) && mid < 0.0f) {
+        return false;
+    }
+
+    if (isPolar(mode)) {
+        const float amplitudeSquared = mid * mid + side * side;
+        if (amplitudeSquared < 1e-12f) {
+            x = 0.0f;
+            y = 0.0f;
+            return true;
+        }
+        const float amplitude = std::sqrt(amplitudeSquared);
+        const float scaledAmplitude = std::pow(amplitude, 0.35f);
+        const float factor = scaledAmplitude / amplitude;
+        x = side * factor;
+        y = mid * factor;
+        return true;
+    }
+
+    x = side;
+    y = mid;
+    return true;
+}
+
+}  // namespace
+
+std::vector<PlotPoint> buildOscilloscopePlot(const std::vector<float>& samples,
+                                             int pixelWidth,
+                                             int pixelHeight) {
+    if (samples.empty() || pixelWidth <= 0 || pixelHeight <= 0) {
+        return {};
+    }
+
+    std::vector<PlotPoint> points;
+    points.reserve(static_cast<size_t>(pixelWidth));
+    const float sampleSpan = static_cast<float>(samples.size() - 1);
+    const float xSpan = static_cast<float>(std::max(1, pixelWidth - 1));
+    const float ySpan = static_cast<float>(std::max(0, pixelHeight - 1));
+    for (int x = 0; x < pixelWidth; ++x) {
+        const float samplePosition = static_cast<float>(x) / xSpan * sampleSpan;
+        const size_t first = std::min(
+            samples.size() - 1,
+            static_cast<size_t>(std::floor(samplePosition)));
+        const size_t second = std::min(samples.size() - 1, first + 1);
+        const float fraction = samplePosition - static_cast<float>(first);
+        const float firstSample = std::isfinite(samples[first]) ? samples[first] : 0.0f;
+        const float secondSample = std::isfinite(samples[second]) ? samples[second] : 0.0f;
+        const float sample = std::clamp(
+            firstSample + (secondSample - firstSample) * fraction,
+            -1.0f,
+            1.0f);
+        const int y = static_cast<int>(std::lround(
+            (1.0f - sample) * 0.5f * ySpan));
+        points.push_back({x, std::clamp(y, 0, pixelHeight - 1)});
+    }
+    return points;
+}
+
+int oscilloscopeZeroY(int pixelHeight) {
+    if (pixelHeight <= 0) {
+        return 0;
+    }
+    return static_cast<int>(std::lround(
+        static_cast<float>(pixelHeight - 1) * 0.5f));
+}
+
+VectorscopeBands buildVectorscopePlot(const std::vector<float>& multibandPoints,
+                                      size_t pointCount,
+                                      int pixelWidth,
+                                      int pixelHeight,
+                                      VectorscopeMode mode,
+                                      int densityDivisor) {
+    VectorscopeBands result;
+    if (pixelWidth <= 0 || pixelHeight <= 0 || multibandPoints.empty()) {
+        return result;
+    }
+
+    const size_t count = std::min(
+        pointCount,
+        multibandPoints.size() / Visualizer::MULTIBAND_POINT_STRIDE);
+    const size_t pixelCapacity = static_cast<size_t>(pixelWidth) *
+        static_cast<size_t>(pixelHeight);
+    const size_t sampleBudget = std::min(
+        count,
+        std::max<size_t>(64, pixelCapacity /
+            static_cast<size_t>(std::max(1, densityDivisor))));
+    const size_t stride = sampleBudget > 0
+        ? std::max<size_t>(1, (count + sampleBudget - 1) / sampleBudget)
+        : 1;
+    const size_t firstIndex = count > 0 ? (count - 1) % stride : 0;
+    for (auto& band : result) {
+        band.reserve(sampleBudget);
+    }
+
+    const auto layout = getVectorscopePlotLayout(pixelWidth, pixelHeight, mode);
+
+    for (size_t index = firstIndex; index < count; index += stride) {
+        const size_t base = index * Visualizer::MULTIBAND_POINT_STRIDE;
+        const float intensity = count > 1
+            ? 0.15f + 0.85f * static_cast<float>(index) /
+                static_cast<float>(count - 1)
+            : 1.0f;
+        for (size_t band = 0; band < result.size(); ++band) {
+            const float leftValue = multibandPoints[base + band * 2];
+            const float rightValue = multibandPoints[base + band * 2 + 1];
+            const float left = std::isfinite(leftValue)
+                ? std::clamp(leftValue, -1.25f, 1.25f)
+                : 0.0f;
+            const float right = std::isfinite(rightValue)
+                ? std::clamp(rightValue, -1.25f, 1.25f)
+                : 0.0f;
+            if (std::abs(left) + std::abs(right) < 1e-5f) {
+                continue;
+            }
+            float transformedX = 0.0f;
+            float transformedY = 0.0f;
+            if (!transformVectorscopePoint(
+                    left, right, mode, transformedX, transformedY)) {
+                continue;
+            }
+            const int x = static_cast<int>(std::lround(
+                static_cast<float>(layout.centerX) +
+                transformedX * static_cast<float>(layout.radius)));
+            const int y = static_cast<int>(std::lround(
+                static_cast<float>(layout.centerY) -
+                transformedY * static_cast<float>(layout.radius)));
+            result[band].push_back({
+                std::clamp(x, 0, pixelWidth - 1),
+                std::clamp(y, 0, pixelHeight - 1),
+                intensity,
+            });
+        }
+    }
+    return result;
+}
+
+VectorscopePlotLayout getVectorscopePlotLayout(int pixelWidth,
+                                               int pixelHeight,
+                                               VectorscopeMode mode) {
+    VectorscopePlotLayout layout;
+    if (pixelWidth <= 0 || pixelHeight <= 0) {
+        return layout;
+    }
+
+    layout.centerX = (pixelWidth - 1) / 2;
+    layout.unipolar = isUnipolar(mode);
+    if (layout.unipolar) {
+        const int margin = std::max(1, pixelHeight / 25);
+        layout.centerY = pixelHeight - 1 - margin;
+        layout.radius = static_cast<int>(std::lround(
+            static_cast<float>(std::min(
+                pixelWidth / 2,
+                std::max(0, layout.centerY))) * 0.88f));
+    } else {
+        layout.centerY = (pixelHeight - 1) / 2;
+        layout.radius = static_cast<int>(std::lround(
+            static_cast<float>(std::min(pixelWidth, pixelHeight)) * 0.45f));
+    }
+    layout.radius = std::max(0, layout.radius);
+    return layout;
+}
+
+VectorscopeMode nextVectorscopeMode(VectorscopeMode mode) {
+    switch (mode) {
+        case VectorscopeMode::Lissajous:
+            return VectorscopeMode::PolarUnipolar;
+        case VectorscopeMode::PolarUnipolar:
+            return VectorscopeMode::PolarBipolar;
+        case VectorscopeMode::PolarBipolar:
+            return VectorscopeMode::LinearUnipolar;
+        case VectorscopeMode::LinearUnipolar:
+            return VectorscopeMode::LinearBipolar;
+        case VectorscopeMode::LinearBipolar:
+            return VectorscopeMode::Lissajous;
+    }
+    return VectorscopeMode::Lissajous;
+}
+
+const char* vectorscopeModeName(VectorscopeMode mode) {
+    switch (mode) {
+        case VectorscopeMode::Lissajous:
+            return "Lissajous";
+        case VectorscopeMode::PolarUnipolar:
+            return "Polar +";
+        case VectorscopeMode::PolarBipolar:
+            return "Polar ±";
+        case VectorscopeMode::LinearUnipolar:
+            return "Linear +";
+        case VectorscopeMode::LinearBipolar:
+            return "Linear ±";
+    }
+    return "Lissajous";
+}
+
+}  // namespace Prism::Tui

tui/src/scope_plot_model.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <array>
+#include <cstddef>
+#include <vector>
+
+namespace Prism::Tui {
+
+struct PlotPoint {
+    int x = 0;
+    int y = 0;
+    float intensity = 1.0f;
+};
+
+enum class VectorscopeMode {
+    Lissajous,
+    PolarUnipolar,
+    PolarBipolar,
+    LinearUnipolar,
+    LinearBipolar,
+};
+
+struct VectorscopePlotLayout {
+    int centerX = 0;
+    int centerY = 0;
+    int radius = 0;
+    bool unipolar = false;
+};
+
+using VectorscopeBands = std::array<std::vector<PlotPoint>, 3>;
+
+std::vector<PlotPoint> buildOscilloscopePlot(const std::vector<float>& samples,
+                                             int pixelWidth,
+                                             int pixelHeight);
+int oscilloscopeZeroY(int pixelHeight);
+
+VectorscopeBands buildVectorscopePlot(const std::vector<float>& multibandPoints,
+                                      size_t pointCount,
+                                      int pixelWidth,
+                                      int pixelHeight,
+                                      VectorscopeMode mode = VectorscopeMode::Lissajous,
+                                      int densityDivisor = 6);
+
+VectorscopePlotLayout getVectorscopePlotLayout(int pixelWidth,
+                                               int pixelHeight,
+                                               VectorscopeMode mode);
+VectorscopeMode nextVectorscopeMode(VectorscopeMode mode);
+const char* vectorscopeModeName(VectorscopeMode mode);
+
+}  // namespace Prism::Tui

tui/src/spectrum_peak_model.cpp

@@ -0,0 +1,178 @@
+#include "spectrum_peak_model.h"
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+#include <iomanip>
+#include <limits>
+#include <sstream>
+
+namespace Prism::Tui {
+namespace {
+
+constexpr float kMinFrequency = 20.0f;
+constexpr float kMaxFrequency = 20000.0f;
+constexpr float kTiltReferenceHz = 1000.0f;
+constexpr float kMaximumStickyDistanceOctaves = 0.5f;
+constexpr float kSwitchThresholdDb = 4.0f;
+constexpr float kLowFrequencyBiasDbPerOctave = 0.75f;
+constexpr float kUpwardSwitchThresholdDb = 2.0f;
+constexpr float kSilenceThresholdDbfs = -90.0f;
+
+float finiteMagnitude(const std::vector<float>& magnitudes, size_t index) {
+    return std::isfinite(magnitudes[index]) ? magnitudes[index] : -120.0f;
+}
+
+float frequencyForBin(float bin, float sampleRate, size_t fftSize) {
+    return bin * sampleRate / static_cast<float>(fftSize);
+}
+
+float displayDb(float dbfs, float frequencyHz, float tiltDbPerOctave) {
+    return dbfs + tiltDbPerOctave * std::log2(
+        std::max(1.0f, frequencyHz) / kTiltReferenceHz);
+}
+
+float score(float dbfs, float frequencyHz, float tiltDbPerOctave) {
+    const float tilted = displayDb(dbfs, frequencyHz, tiltDbPerOctave);
+    const float octaveOffset = std::max(
+        0.0f, std::log2(std::max(1.0f, frequencyHz) / kMinFrequency));
+    return tilted - octaveOffset * kLowFrequencyBiasDbPerOctave;
+}
+
+SpectrumPeakInfo peakAt(const std::vector<float>& magnitudes,
+                        size_t bin,
+                        float sampleRate,
+                        size_t fftSize) {
+    float offset = 0.0f;
+    float dbfs = finiteMagnitude(magnitudes, bin);
+    if (bin > 0 && bin + 1 < magnitudes.size()) {
+        const float previous = finiteMagnitude(magnitudes, bin - 1);
+        const float current = dbfs;
+        const float next = finiteMagnitude(magnitudes, bin + 1);
+        const float denominator = previous - 2.0f * current + next;
+        if (std::abs(denominator) > 1.0e-9f) {
+            offset = std::clamp(
+                0.5f * (previous - next) / denominator, -0.5f, 0.5f);
+            dbfs = current - 0.25f * (previous - next) * offset;
+        }
+    }
+    const float frequency = frequencyForBin(
+        static_cast<float>(bin) + offset, sampleRate, fftSize);
+    return {dbfs, frequency, formatSpectrumPitch(frequency)};
+}
+
+}  // namespace
+
+std::string formatSpectrumPitch(float frequencyHz) {
+    if (!std::isfinite(frequencyHz) || frequencyHz <= 0.0f) {
+        return "--";
+    }
+    static constexpr std::array<const char*, 12> noteNames = {
+        "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B",
+    };
+    const float midi = 69.0f + 12.0f * std::log2(frequencyHz / 440.0f);
+    const int nearest = static_cast<int>(std::lround(midi));
+    const int cents = static_cast<int>(std::lround((midi - nearest) * 100.0f));
+    const int noteIndex = ((nearest % 12) + 12) % 12;
+    const int octave = static_cast<int>(std::floor(static_cast<float>(nearest) / 12.0f)) - 1;
+    std::ostringstream output;
+    output << noteNames[static_cast<size_t>(noteIndex)] << octave << ' '
+           << (cents > 0 ? "+" : "") << cents << 'c';
+    return output.str();
+}
+
+std::optional<SpectrumPeakInfo> SpectrumPeakTracker::select(
+    const std::vector<float>& magnitudes,
+    float sampleRate,
+    size_t fftSize,
+    float tiltDbPerOctave) {
+    if (magnitudes.size() < 3 || sampleRate <= 0.0f || fftSize == 0) {
+        previous_.reset();
+        return std::nullopt;
+    }
+
+    const float binWidth = sampleRate / static_cast<float>(fftSize);
+    const size_t firstBin = std::clamp<size_t>(
+        static_cast<size_t>(std::ceil(kMinFrequency / binWidth)),
+        1,
+        magnitudes.size() - 2);
+    const size_t lastBin = std::clamp<size_t>(
+        static_cast<size_t>(std::floor(
+            std::min(kMaxFrequency, sampleRate * 0.5f) / binWidth)),
+        firstBin,
+        magnitudes.size() - 2);
+
+    std::vector<size_t> candidates;
+    for (size_t bin = firstBin; bin <= lastBin; ++bin) {
+        const float previous = finiteMagnitude(magnitudes, bin - 1);
+        const float current = finiteMagnitude(magnitudes, bin);
+        const float next = finiteMagnitude(magnitudes, bin + 1);
+        if (current >= previous && current >= next &&
+            (current > previous || current > next)) {
+            candidates.push_back(bin);
+        }
+    }
+    if (candidates.empty()) {
+        const auto best = std::max_element(
+            magnitudes.begin() + static_cast<std::ptrdiff_t>(firstBin),
+            magnitudes.begin() + static_cast<std::ptrdiff_t>(lastBin + 1));
+        candidates.push_back(static_cast<size_t>(
+            std::distance(magnitudes.begin(), best)));
+    }
+
+    const auto candidateScore = [&](size_t bin) {
+        const float frequency = frequencyForBin(
+            static_cast<float>(bin), sampleRate, fftSize);
+        return score(finiteMagnitude(magnitudes, bin), frequency, tiltDbPerOctave);
+    };
+    const auto better = [&](size_t left, size_t right) {
+        const float leftScore = candidateScore(left);
+        const float rightScore = candidateScore(right);
+        if (leftScore != rightScore) return leftScore > rightScore;
+        const float leftDb = finiteMagnitude(magnitudes, left);
+        const float rightDb = finiteMagnitude(magnitudes, right);
+        return leftDb != rightDb ? leftDb > rightDb : left < right;
+    };
+
+    size_t strongest = candidates.front();
+    for (size_t candidate : candidates) {
+        if (better(candidate, strongest)) strongest = candidate;
+    }
+    size_t selected = strongest;
+    if (previous_ && previous_->frequencyHz > 0.0f) {
+        std::optional<size_t> sticky;
+        for (size_t candidate : candidates) {
+            const float frequency = frequencyForBin(
+                static_cast<float>(candidate), sampleRate, fftSize);
+            const float distance = std::abs(std::log2(
+                frequency / previous_->frequencyHz));
+            if (distance <= kMaximumStickyDistanceOctaves &&
+                (!sticky || better(candidate, *sticky))) {
+                sticky = candidate;
+            }
+        }
+        if (sticky) {
+            const float upwardPenalty = strongest > *sticky
+                ? kUpwardSwitchThresholdDb
+                : 0.0f;
+            if (candidateScore(strongest) <
+                candidateScore(*sticky) + kSwitchThresholdDb + upwardPenalty) {
+                selected = *sticky;
+            }
+        }
+    }
+
+    SpectrumPeakInfo result = peakAt(magnitudes, selected, sampleRate, fftSize);
+    if (!std::isfinite(result.dbfs) || result.dbfs <= kSilenceThresholdDbfs) {
+        previous_.reset();
+        return std::nullopt;
+    }
+    previous_ = result;
+    return result;
+}
+
+void SpectrumPeakTracker::reset() {
+    previous_.reset();
+}
+
+}  // namespace Prism::Tui

tui/src/spectrum_peak_model.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace Prism::Tui {
+
+struct SpectrumPeakInfo {
+    float dbfs = -100.0f;
+    float frequencyHz = 0.0f;
+    std::string pitch;
+};
+
+std::string formatSpectrumPitch(float frequencyHz);
+
+class SpectrumPeakTracker {
+public:
+    std::optional<SpectrumPeakInfo> select(const std::vector<float>& magnitudes,
+                                           float sampleRate,
+                                           size_t fftSize,
+                                           float tiltDbPerOctave);
+    void reset();
+
+private:
+    std::optional<SpectrumPeakInfo> previous_;
+};
+
+}  // namespace Prism::Tui

tui/src/tui_runtime.cpp

@@ -3,21 +3,27 @@
 #include "analysis_pipeline.h"
 #include "dashboard_layout.h"
 #include "display_model.h"
+#include "scope_plot_model.h"
 #include "snapshot_store.h"
+#include "tui_settings.h"
 
 #include <ftxui/component/component.hpp>
 #include <ftxui/component/event.hpp>
 #include <ftxui/component/screen_interactive.hpp>
+#include <ftxui/dom/canvas.hpp>
 #include <ftxui/dom/elements.hpp>
 
 #include <algorithm>
+#include <array>
 #include <atomic>
 #include <chrono>
 #include <cmath>
+#include <cstdint>
 #include <csignal>
 #include <cstdio>
 #include <exception>
 #include <iomanip>
+#include <optional>
 #include <sstream>
 #include <string>
 #include <thread>
@@ -34,7 +40,11 @@ namespace Prism::Tui {
 namespace {
 
 constexpr auto kCapturePollInterval = std::chrono::milliseconds(2);
-constexpr auto kDisplayFrameInterval = std::chrono::milliseconds(33);
+
+std::chrono::microseconds displayFrameInterval(int framesPerSecond) {
+    return std::chrono::microseconds(
+        1000000 / std::max(1, framesPerSecond));
+}
 
 volatile std::sig_atomic_t signalRequested = 0;
 
@@ -61,8 +71,11 @@ private:
 
 struct DisplayFrame {
     std::vector<float> magnitudes;
+    std::optional<SpectrumPeakInfo> spectrumPeak;
     Visualizer::VUMeterSnapshot vu{};
     Visualizer::LUFSMeterSnapshot lufs{};
+    OscilloscopeFrame oscilloscope;
+    VectorscopeFrame vectorscope;
     double sampleRate = 48000.0;
     std::string backend;
     std::string device;
@@ -71,11 +84,30 @@ struct DisplayFrame {
 
 struct InterfaceState {
     PanelId focusedPanel = PanelId::Spectrum;
-    LayoutPreset layoutPreset = LayoutPreset::Automatic;
     std::optional<PanelId> expandedPanel;
+    TuiSettings settings;
+    bool settingsOpen = false;
+    SettingsPage settingsPage = SettingsPage::Home;
+    size_t settingsHomeSelection = 0;
+    std::array<size_t, 5> settingsSelections{};
+    std::string settingsStatus;
 };
 
-std::string makeCaptureStatus(const DisplayFrame& frame, bool compact) {
+size_t settingsPageIndex(SettingsPage page) {
+    return static_cast<size_t>(page);
+}
+
+size_t& settingsSelection(InterfaceState& state) {
+    return state.settingsSelections[settingsPageIndex(state.settingsPage)];
+}
+
+const size_t& settingsSelection(const InterfaceState& state) {
+    return state.settingsSelections[settingsPageIndex(state.settingsPage)];
+}
+
+std::string makeCaptureStatus(const DisplayFrame& frame,
+                              const TuiSettings& settings,
+                              bool compact) {
     std::ostringstream sampleRate;
     const double kilohertz = frame.sampleRate / 1000.0;
     sampleRate << std::fixed << std::setprecision(
@@ -85,28 +117,68 @@ std::string makeCaptureStatus(const DisplayFrame& frame, bool compact) {
         footer += frame.device + " • ";
     }
     footer += sampleRate.str() + " kHz";
+    if (settings.inputTrimDb != 0.0f) {
+        std::ostringstream trim;
+        trim << " • trim " << (settings.inputTrimDb > 0.0f ? "+" : "")
+             << std::fixed << std::setprecision(1) << settings.inputTrimDb << " dB";
+        footer += trim.str();
+    }
     if (frame.captureOverrun) {
         footer += " • capture overrun";
     }
     return footer;
 }
 
+std::string formatSpectrumPeak(const SpectrumPeakInfo& peak, int width) {
+    std::ostringstream frequency;
+    frequency << std::fixed << std::setprecision(
+        peak.frequencyHz < 1000.0f ? 1 : 0) << peak.frequencyHz << " Hz";
+    if (width < 42) {
+        return frequency.str();
+    }
+    std::ostringstream db;
+    db << std::fixed << std::setprecision(1) << peak.dbfs << " dBFS";
+    if (width < 58) {
+        return db.str() + " • " + frequency.str();
+    }
+    return db.str() + " • " + frequency.str() + " • " + peak.pitch;
+}
+
 std::string panelName(PanelId panel) {
     switch (panel) {
         case PanelId::Spectrum:
             return "Spectrum";
+        case PanelId::Oscilloscope:
+            return "Oscilloscope";
+        case PanelId::Vectorscope:
+            return "Vectorscope";
         case PanelId::Levels:
             return "Levels";
     }
     return "Panel";
 }
 
-ftxui::Element panelTitle(PanelId panel, bool focused) {
+std::string panelNumber(PanelId panel) {
+    switch (panel) {
+        case PanelId::Spectrum:
+            return "1";
+        case PanelId::Oscilloscope:
+            return "2";
+        case PanelId::Vectorscope:
+            return "3";
+        case PanelId::Levels:
+            return "4";
+    }
+    return "?";
+}
+
+ftxui::Element panelTitle(PanelId panel,
+                          bool focused,
+                          const std::string& detail = {}) {
     using namespace ftxui;
-    const std::string number = panel == PanelId::Spectrum ? "1" : "2";
-    std::string label = " " + number + " " + panelName(panel);
-    if (panel == PanelId::Spectrum) {
-        label += "  •  FFT " + std::to_string(kDefaultFftSize);
+    std::string label = " " + panelNumber(panel) + " " + panelName(panel);
+    if (!detail.empty()) {
+        label += "  •  " + detail;
     }
     label += " ";
     auto title = text(label);
@@ -123,7 +195,8 @@ ftxui::Element stylePanel(ftxui::Element content, bool focused) {
 ftxui::Element renderSpectrumPanel(const DisplayFrame& frame,
                                    int width,
                                    int height,
-                                   bool focused) {
+                                   bool focused,
+                                   const TuiSettings& settings) {
     using namespace ftxui;
     const size_t contentWidth = static_cast<size_t>(std::max(1, width - 2));
     const size_t contentHeight = static_cast<size_t>(std::max(1, height - 2));
@@ -132,6 +205,7 @@ ftxui::Element renderSpectrumPanel(const DisplayFrame& frame,
     SpectrumProjectionOptions projectionOptions;
     projectionOptions.sampleRate = static_cast<float>(frame.sampleRate);
     projectionOptions.maxFrequency = std::min(20000.0f, projectionOptions.sampleRate * 0.5f);
+    projectionOptions.tiltDbPerOctave = settings.spectrumTiltDbPerOctave;
     const auto projected = projectSpectrum(
         frame.magnitudes,
         kDefaultFftSize,
@@ -150,14 +224,250 @@ ftxui::Element renderSpectrumPanel(const DisplayFrame& frame,
             color(Color::GrayDark));
     }
 
+    const std::string detail = settings.spectrumPeakReadout && frame.spectrumPeak
+        ? formatSpectrumPeak(*frame.spectrumPeak, width)
+        : "FFT " + std::to_string(kDefaultFftSize);
     auto panel = window(
-        panelTitle(PanelId::Spectrum, focused),
+        panelTitle(
+            PanelId::Spectrum,
+            focused,
+            detail),
         vbox(std::move(spectrumElements)));
     return stylePanel(std::move(panel), focused) |
         size(WIDTH, EQUAL, std::max(1, width)) |
         size(HEIGHT, EQUAL, std::max(1, height));
 }
 
+ftxui::Element renderOscilloscopePanel(const DisplayFrame& frame,
+                                       int width,
+                                       int height,
+                                       bool focused,
+                                       const TuiSettings& settings) {
+    using namespace ftxui;
+    std::string detail = settings.oscilloscopePitchLock ? "Pitch lock" : "Free run";
+    if (settings.oscilloscopeFrequencyReadout &&
+        frame.oscilloscope.signalPresent &&
+        std::isfinite(frame.oscilloscope.detectedPitch) &&
+        frame.oscilloscope.detectedPitch > 0.0f) {
+        detail = std::to_string(static_cast<int>(
+            std::lround(frame.oscilloscope.detectedPitch))) + " Hz" +
+            (settings.oscilloscopePitchLock ? " lock" : "");
+    }
+
+    auto plot = canvas([
+        samples = frame.oscilloscope.samples,
+        signalPresent = frame.oscilloscope.signalPresent,
+        traceWeight = settings.oscilloscopeTraceWeight
+    ](Canvas& surface) {
+        const int canvasWidth = surface.width();
+        const int canvasHeight = surface.height();
+        if (canvasWidth <= 0 || canvasHeight <= 0) {
+            return;
+        }
+
+        const int centerY = oscilloscopeZeroY(canvasHeight);
+        surface.DrawPointLine(
+            0, centerY, canvasWidth - 1, centerY, Color::GrayDark);
+        if (!signalPresent) {
+            return;
+        }
+        const auto points = buildOscilloscopePlot(
+            samples, canvasWidth, canvasHeight);
+        for (size_t index = 1; index < points.size(); ++index) {
+            for (int thickness = 0; thickness < traceWeight; ++thickness) {
+                surface.DrawPointLine(
+                    points[index - 1].x,
+                    std::clamp(points[index - 1].y + thickness, 0, canvasHeight - 1),
+                    points[index].x,
+                    std::clamp(points[index].y + thickness, 0, canvasHeight - 1),
+                    Color::CyanLight);
+            }
+        }
+    }) | flex;
+
+    auto panel = window(
+        panelTitle(PanelId::Oscilloscope, focused, detail),
+        std::move(plot));
+    return stylePanel(std::move(panel), focused) |
+        size(WIDTH, EQUAL, std::max(1, width)) |
+        size(HEIGHT, EQUAL, std::max(1, height));
+}
+
+void drawVectorscopeGrid(ftxui::Canvas& surface, VectorscopeMode mode) {
+    using ftxui::Color;
+    const auto layout = getVectorscopePlotLayout(
+        surface.width(), surface.height(), mode);
+    if (layout.radius <= 0 || mode == VectorscopeMode::Lissajous) {
+        return;
+    }
+
+    const auto grid = Color::RGB(76, 82, 88);
+    const auto guide = Color::RGB(48, 53, 58);
+    const int left = layout.centerX - layout.radius;
+    const int right = layout.centerX + layout.radius;
+    const int top = layout.centerY - layout.radius;
+    const int bottom = layout.centerY + layout.radius;
+    const int halfRadius = std::max(1, layout.radius / 2);
+    const int diagonal = static_cast<int>(std::lround(
+        static_cast<float>(layout.radius) * 0.70710678f));
+    const auto drawTriangle = [&](int radius, const Color& color) {
+        surface.DrawPointLine(
+            layout.centerX, layout.centerY - radius,
+            layout.centerX - radius, layout.centerY, color);
+        surface.DrawPointLine(
+            layout.centerX - radius, layout.centerY,
+            layout.centerX + radius, layout.centerY, color);
+        surface.DrawPointLine(
+            layout.centerX + radius, layout.centerY,
+            layout.centerX, layout.centerY - radius, color);
+    };
+    const auto drawDiamond = [&](int radius, const Color& color) {
+        surface.DrawPointLine(
+            layout.centerX, layout.centerY - radius,
+            layout.centerX + radius, layout.centerY, color);
+        surface.DrawPointLine(
+            layout.centerX + radius, layout.centerY,
+            layout.centerX, layout.centerY + radius, color);
+        surface.DrawPointLine(
+            layout.centerX, layout.centerY + radius,
+            layout.centerX - radius, layout.centerY, color);
+        surface.DrawPointLine(
+            layout.centerX - radius, layout.centerY,
+            layout.centerX, layout.centerY - radius, color);
+    };
+    switch (mode) {
+        case VectorscopeMode::PolarUnipolar:
+            surface.DrawPointCircle(
+                layout.centerX, layout.centerY, layout.radius, grid);
+            surface.DrawPointCircle(
+                layout.centerX, layout.centerY, halfRadius, guide);
+            surface.DrawPointLine(
+                layout.centerX, top, layout.centerX, layout.centerY, grid);
+            surface.DrawPointLine(
+                layout.centerX, layout.centerY,
+                layout.centerX - diagonal, layout.centerY - diagonal, guide);
+            surface.DrawPointLine(
+                layout.centerX, layout.centerY,
+                layout.centerX + diagonal, layout.centerY - diagonal, guide);
+            break;
+        case VectorscopeMode::PolarBipolar:
+            surface.DrawPointCircle(
+                layout.centerX, layout.centerY, layout.radius, grid);
+            surface.DrawPointCircle(
+                layout.centerX, layout.centerY, halfRadius, guide);
+            surface.DrawPointLine(
+                layout.centerX, top, layout.centerX, bottom, grid);
+            surface.DrawPointLine(
+                left, layout.centerY, right, layout.centerY, guide);
+            surface.DrawPointLine(
+                layout.centerX - diagonal, layout.centerY - diagonal,
+                layout.centerX + diagonal, layout.centerY + diagonal, guide);
+            surface.DrawPointLine(
+                layout.centerX + diagonal, layout.centerY - diagonal,
+                layout.centerX - diagonal, layout.centerY + diagonal, guide);
+            break;
+        case VectorscopeMode::LinearUnipolar:
+            drawTriangle(layout.radius, grid);
+            drawTriangle(halfRadius, guide);
+            surface.DrawPointLine(
+                layout.centerX, top, layout.centerX, layout.centerY, grid);
+            break;
+        case VectorscopeMode::LinearBipolar:
+            drawDiamond(layout.radius, grid);
+            drawDiamond(halfRadius, guide);
+            surface.DrawPointLine(
+                layout.centerX, top, layout.centerX, bottom, grid);
+            surface.DrawPointLine(
+                left, layout.centerY, right, layout.centerY, guide);
+            break;
+        case VectorscopeMode::Lissajous:
+            break;
+    }
+}
+
+ftxui::Element renderVectorscopePanel(const DisplayFrame& frame,
+                                      int width,
+                                      int height,
+                                      bool focused,
+                                      const TuiSettings& settings) {
+    using namespace ftxui;
+    const VectorscopeMode mode = settings.vectorscopeMode;
+    const int densityDivisor = settings.vectorscopeDetail == VectorscopeDetail::Balanced
+        ? 10
+        : settings.vectorscopeDetail == VectorscopeDetail::Maximum ? 3 : 6;
+    auto plot = canvas([
+        multibandPoints = frame.vectorscope.multibandPoints,
+        pointCount = frame.vectorscope.pointCount,
+        mode,
+        showGuides = settings.vectorscopeGuides,
+        densityDivisor
+    ](Canvas& surface) {
+        const int canvasWidth = surface.width();
+        const int canvasHeight = surface.height();
+        if (canvasWidth <= 0 || canvasHeight <= 0) {
+            return;
+        }
+
+        if (showGuides) {
+            drawVectorscopeGrid(surface, mode);
+        }
+
+        const auto bands = buildVectorscopePlot(
+            multibandPoints,
+            pointCount,
+            canvasWidth,
+            canvasHeight,
+            mode,
+            densityDivisor);
+        constexpr int ageBuckets = 8;
+        const std::array<std::array<int, 3>, 3> baseColors = {{
+            {{255, 68, 68}},
+            {{68, 221, 68}},
+            {{68, 136, 255}},
+        }};
+        std::array<std::array<Color, ageBuckets>, 3> colors;
+        for (size_t band = 0; band < colors.size(); ++band) {
+            for (int bucket = 0; bucket < ageBuckets; ++bucket) {
+                const float brightness = 0.3f + 0.7f *
+                    static_cast<float>(bucket + 1) /
+                    static_cast<float>(ageBuckets);
+                colors[band][bucket] = Color::RGB(
+                    static_cast<uint8_t>(std::lround(
+                        static_cast<float>(baseColors[band][0]) * brightness)),
+                    static_cast<uint8_t>(std::lround(
+                        static_cast<float>(baseColors[band][1]) * brightness)),
+                    static_cast<uint8_t>(std::lround(
+                        static_cast<float>(baseColors[band][2]) * brightness)));
+            }
+        }
+        for (int bucket = 0; bucket < ageBuckets; ++bucket) {
+            for (size_t band = 0; band < bands.size(); ++band) {
+                for (const auto& point : bands[band]) {
+                    const int pointBucket = std::min(
+                        ageBuckets - 1,
+                        static_cast<int>(point.intensity *
+                            static_cast<float>(ageBuckets)));
+                    if (pointBucket != bucket) {
+                        continue;
+                    }
+                    surface.DrawPoint(
+                        point.x, point.y, true, colors[band][bucket]);
+                }
+            }
+        }
+    }) | flex;
+
+    auto panel = window(
+        panelTitle(
+            PanelId::Vectorscope,
+            focused,
+            vectorscopeModeName(mode)),
+        std::move(plot));
+    return stylePanel(std::move(panel), focused) |
+        size(WIDTH, EQUAL, std::max(1, width)) |
+        size(HEIGHT, EQUAL, std::max(1, height));
+}
+
 ftxui::Element renderLevelsPanel(const DisplayFrame& frame,
                                  int width,
                                  int height,
@@ -219,17 +529,28 @@ const PanelRect* findPanelRect(const DashboardLayout& layout, PanelId panel) {
 ftxui::Element renderLayoutNode(const LayoutNode& node,
                                 const DashboardLayout& layout,
                                 const DisplayFrame& frame,
-                                PanelId focusedPanel) {
+                                const InterfaceState& state) {
     using namespace ftxui;
     if (node.isLeaf()) {
         const auto* rect = findPanelRect(layout, *node.panel);
         if (rect == nullptr) {
             return emptyElement();
         }
-        const bool focused = *node.panel == focusedPanel;
+        const bool focused = *node.panel == state.focusedPanel;
         switch (*node.panel) {
             case PanelId::Spectrum:
-                return renderSpectrumPanel(frame, rect->width, rect->height, focused);
+                return renderSpectrumPanel(
+                    frame, rect->width, rect->height, focused, state.settings);
+            case PanelId::Oscilloscope:
+                return renderOscilloscopePanel(
+                    frame, rect->width, rect->height, focused, state.settings);
+            case PanelId::Vectorscope:
+                return renderVectorscopePanel(
+                    frame,
+                    rect->width,
+                    rect->height,
+                    focused,
+                    state.settings);
             case PanelId::Levels:
                 return renderLevelsPanel(frame, rect->width, rect->height, focused);
         }
@@ -238,7 +559,7 @@ ftxui::Element renderLayoutNode(const LayoutNode& node,
     Elements children;
     children.reserve(node.children.size());
     for (const auto& child : node.children) {
-        children.push_back(renderLayoutNode(child, layout, frame, focusedPanel));
+        children.push_back(renderLayoutNode(child, layout, frame, state));
     }
     return node.axis == SplitAxis::Columns
         ? hbox(std::move(children))
@@ -248,8 +569,8 @@ ftxui::Element renderLayoutNode(const LayoutNode& node,
 ftxui::Element renderHeader(const DashboardLayout& layout,
                             const InterfaceState& state) {
     using namespace ftxui;
-    std::string layoutName = layoutPresetName(state.layoutPreset);
-    if (state.layoutPreset == LayoutPreset::Automatic) {
+    std::string layoutName = layoutPresetName(state.settings.layoutPreset);
+    if (state.settings.layoutPreset == LayoutPreset::Automatic) {
         layoutName += "→" + layoutPresetName(layout.resolvedPreset);
     }
     return hbox({
@@ -270,11 +591,12 @@ ftxui::Element renderFooter(const DisplayFrame& frame,
     const bool minimal = width < 64;
     const std::string enterAction = state.expandedPanel ? "restore" : "expand";
     const std::string controls = minimal
-        ? "Tab • Enter • l • q"
+        ? "Tab • Enter • s • q"
         : compact
-            ? "Tab focus • Enter " + enterAction + " • l layout • q quit"
-            : "Tab focus • Enter " + enterAction + " • l layout • r reset • q quit";
-    auto status = text(makeCaptureStatus(frame, compact)) | dim;
+            ? "Tab focus • Enter " + enterAction + " • s settings • q quit"
+            : "Tab focus • Enter " + enterAction +
+                " • s settings • v mode • l layout • r reset • q quit";
+    auto status = text(makeCaptureStatus(frame, state.settings, compact)) | dim;
     if (frame.captureOverrun) {
         status = status | color(Color::RedLight);
     }
@@ -285,13 +607,109 @@ ftxui::Element renderFooter(const DisplayFrame& frame,
     });
 }
 
+ftxui::Element settingsRow(const std::string& label,
+                           const std::string& value,
+                           bool selected) {
+    using namespace ftxui;
+    auto row = hbox({
+        text(selected ? " › " : "   "),
+        text(label),
+        filler(),
+        text(value),
+        text(" "),
+    });
+    if (selected) {
+        row = row | color(Color::CyanLight) | bold |
+            bgcolor(Color::RGB(24, 42, 46));
+    } else {
+        row = row | color(Color::GrayLight);
+    }
+    return row | size(HEIGHT, EQUAL, 1);
+}
+
+ftxui::Element renderSettings(const InterfaceState& state,
+                              int width,
+                              int height) {
+    using namespace ftxui;
+    const int contentWidth = std::max(1, width - 2);
+    const int contentHeight = std::max(1, height - 2);
+    const std::string breadcrumb = state.settingsPage == SettingsPage::Home
+        ? " PRISM / SETTINGS"
+        : " PRISM / SETTINGS › " + std::string(settingsPageName(state.settingsPage));
+    Elements rows;
+    std::string selectedDescription;
+    const size_t maximumVisibleRows = static_cast<size_t>(
+        std::max(1, contentHeight - 8));
+    if (state.settingsPage == SettingsPage::Home) {
+        const auto pages = settingsPages();
+        const size_t selectedIndex = std::min(
+            state.settingsHomeSelection,
+            pages.empty() ? size_t{0} : pages.size() - 1);
+        const size_t firstVisible = selectedIndex >= maximumVisibleRows
+            ? selectedIndex - maximumVisibleRows + 1
+            : 0;
+        const size_t lastVisible = std::min(
+            pages.size(), firstVisible + maximumVisibleRows);
+        for (size_t index = firstVisible; index < lastVisible; ++index) {
+            const bool selected = index == state.settingsHomeSelection;
+            rows.push_back(settingsRow(
+                std::to_string(index + 1) + "  " + settingsPageName(pages[index]),
+                {},
+                selected));
+            if (selected) selectedDescription = settingsPageDescription(pages[index]);
+        }
+    } else {
+        const auto& settings = settingsForPage(state.settingsPage);
+        const size_t selectedIndex = std::min(
+            settingsSelection(state),
+            settings.empty() ? size_t{0} : settings.size() - 1);
+        const size_t firstVisible = selectedIndex >= maximumVisibleRows
+            ? selectedIndex - maximumVisibleRows + 1
+            : 0;
+        const size_t lastVisible = std::min(
+            settings.size(), firstVisible + maximumVisibleRows);
+        for (size_t index = firstVisible; index < lastVisible; ++index) {
+            const bool selected = index == selectedIndex;
+            rows.push_back(settingsRow(
+                settings[index].name,
+                settingValue(state.settings, settings[index].id),
+                selected));
+            if (selected) selectedDescription = settings[index].description;
+        }
+    }
+
+    const std::string controls = state.settingsPage == SettingsPage::Home
+        ? "↑↓ select  •  Enter open  •  s/Esc dashboard"
+        : contentWidth < 76
+            ? "↑↓ select  •  ←→ adjust  •  Enter  •  Esc back"
+            : "↑↓ select  •  ←→ adjust  •  Enter toggle  •  Backspace default  •  Esc back";
+    auto content = vbox({
+        text(breadcrumb) | color(Color::CyanLight) | bold,
+        separator(),
+        text(settingsPageDescription(state.settingsPage)) | dim,
+        separatorEmpty(),
+        vbox(std::move(rows)),
+        filler(),
+        text(selectedDescription) | color(Color::GrayLight),
+        state.settingsStatus.empty()
+            ? emptyElement()
+            : text(state.settingsStatus) | color(Color::RedLight),
+        separator(),
+        text(controls) | dim,
+    }) | size(WIDTH, EQUAL, contentWidth) |
+        size(HEIGHT, EQUAL, contentHeight);
+    return std::move(content) | borderRounded |
+        size(WIDTH, EQUAL, width) |
+        size(HEIGHT, EQUAL, height);
+}
+
 ftxui::Element renderFrame(const DisplayFrame& frame,
                            int width,
                            int height,
                            const InterfaceState& state) {
     using namespace ftxui;
     const auto layout = buildDashboardLayout(
-        width, height, state.layoutPreset, state.expandedPanel);
+        width, height, state.settings.layoutPreset, state.expandedPanel);
     if (layout.terminalTooSmall) {
         return vbox({
             filler(),
@@ -302,11 +720,22 @@ ftxui::Element renderFrame(const DisplayFrame& frame,
         });
     }
 
-    return vbox({
+    auto dashboard = vbox({
         renderHeader(layout, state) | size(HEIGHT, EQUAL, 1),
-        renderLayoutNode(layout.root, layout, frame, state.focusedPanel),
+        renderLayoutNode(layout.root, layout, frame, state),
         renderFooter(frame, state, width) | size(HEIGHT, EQUAL, 1),
     });
+    if (!state.settingsOpen) {
+        return dashboard;
+    }
+
+    const int settingsWidth = std::min(84, std::max(40, width - 4));
+    const int settingsHeight = std::min(16, std::max(10, height - 2));
+    return dbox({
+        std::move(dashboard) | dim,
+        renderSettings(state, settingsWidth, settingsHeight) |
+            borderEmpty | clear_under | center,
+    });
 }
 
 }  // namespace
@@ -327,7 +756,11 @@ int runInteractive(std::unique_ptr<Prism::Capture::SystemAudioCapture> capture,
 
     ScreenInteractive screen = ScreenInteractive::Fullscreen();
     SnapshotStore<DisplayFrame> frameStore;
+    SnapshotStore<TuiSettings> settingsStore;
     InterfaceState interfaceState;
+    const std::filesystem::path settingsPath = defaultSettingsPath();
+    interfaceState.settings = loadSettings(settingsPath);
+    settingsStore.publish(interfaceState.settings);
     DisplayFrame initial;
     initial.magnitudes.assign(kDefaultFftSize / 2, -100.0f);
     initial.sampleRate = started.sampleRate;
@@ -337,12 +770,17 @@ int runInteractive(std::unique_ptr<Prism::Capture::SystemAudioCapture> capture,
 
     std::atomic<bool> running{true};
     std::atomic<bool> resetRequested{false};
+    std::atomic<bool> redrawQueued{false};
     std::exception_ptr workerError;
     auto exitLoop = screen.ExitLoopClosure();
 
     std::thread worker([&]() {
         try {
             AnalysisPipeline pipeline(static_cast<float>(started.sampleRate));
+            TuiSettings appliedSettings = settingsStore.read();
+            pipeline.setInputTrimDb(appliedSettings.inputTrimDb);
+            pipeline.setSpectrumTilt(appliedSettings.spectrumTiltDbPerOctave);
+            pipeline.setOscilloscopePitchLock(appliedSettings.oscilloscopePitchLock);
 
             bool captureOverrun = false;
             auto nextFrameAt = std::chrono::steady_clock::now();
@@ -357,6 +795,21 @@ int runInteractive(std::unique_ptr<Prism::Capture::SystemAudioCapture> capture,
                     captureOverrun = false;
                 }
 
+                const TuiSettings requestedSettings = settingsStore.read();
+                if (requestedSettings != appliedSettings) {
+                    const bool refreshChanged =
+                        requestedSettings.refreshRate != appliedSettings.refreshRate;
+                    pipeline.setInputTrimDb(requestedSettings.inputTrimDb);
+                    pipeline.setSpectrumTilt(
+                        requestedSettings.spectrumTiltDbPerOctave);
+                    pipeline.setOscilloscopePitchLock(
+                        requestedSettings.oscilloscopePitchLock);
+                    appliedSettings = requestedSettings;
+                    if (refreshChanged) {
+                        nextFrameAt = std::chrono::steady_clock::now();
+                    }
+                }
+
                 drainCapture(*capture, pipeline, captureOverrun);
 
                 const auto now = std::chrono::steady_clock::now();
@@ -364,15 +817,21 @@ int runInteractive(std::unique_ptr<Prism::Capture::SystemAudioCapture> capture,
                     DisplayFrame next;
                     auto analyzed = pipeline.snapshot();
                     next.magnitudes = std::move(analyzed.magnitudes);
+                    next.spectrumPeak = std::move(analyzed.spectrumPeak);
                     next.vu = analyzed.vu;
                     next.lufs = analyzed.lufs;
+                    next.oscilloscope = std::move(analyzed.oscilloscope);
+                    next.vectorscope = std::move(analyzed.vectorscope);
                     next.sampleRate = started.sampleRate;
                     next.backend = capture->backendName();
                     next.device = started.deviceLabel.empty() ? started.deviceId : started.deviceLabel;
                     next.captureOverrun = captureOverrun;
                     frameStore.publish(std::move(next));
-                    screen.PostEvent(Event::Custom);
-                    nextFrameAt = now + kDisplayFrameInterval;
+                    if (running.load() && !redrawQueued.exchange(true)) {
+                        screen.PostEvent(Event::Custom);
+                    }
+                    nextFrameAt = now + displayFrameInterval(
+                        appliedSettings.refreshRate);
                 }
                 std::this_thread::sleep_for(kCapturePollInterval);
             }
@@ -388,8 +847,126 @@ int runInteractive(std::unique_ptr<Prism::Capture::SystemAudioCapture> capture,
         return renderFrame(
             frameStore.read(), screen.dimx(), screen.dimy(), interfaceState);
     });
+    const auto persistSettings = [&]() {
+        interfaceState.settings = normalizeSettings(interfaceState.settings);
+        settingsStore.publish(interfaceState.settings);
+        std::string error;
+        if (!saveSettings(interfaceState.settings, settingsPath, &error)) {
+            interfaceState.settingsStatus = "Settings were applied but could not be saved: " + error;
+        } else {
+            interfaceState.settingsStatus.clear();
+        }
+    };
+    const auto closeSettings = [&]() {
+        interfaceState.settingsOpen = false;
+        interfaceState.settingsPage = SettingsPage::Home;
+        const auto dashboard = buildDashboardLayout(
+            screen.dimx(),
+            screen.dimy(),
+            interfaceState.settings.layoutPreset,
+            interfaceState.expandedPanel);
+        if (!interfaceState.expandedPanel &&
+            !layoutContainsPanel(dashboard, interfaceState.focusedPanel)) {
+            const auto visible = visiblePanelOrder(dashboard);
+            if (!visible.empty()) interfaceState.focusedPanel = visible.front();
+        }
+    };
     auto component = CatchEvent(renderer, [&](Event event) {
-        if (event == Event::Character('q') || event == Event::Escape || event == Event::CtrlC) {
+        if (event == Event::Custom) {
+            redrawQueued.store(false);
+            return false;
+        }
+        if (event == Event::Character('q') || event == Event::CtrlC) {
+            running.store(false);
+            exitLoop();
+            return true;
+        }
+        if (event == Event::Character('s')) {
+            if (interfaceState.settingsOpen) {
+                closeSettings();
+            } else {
+                interfaceState.settingsOpen = true;
+                interfaceState.settingsPage = SettingsPage::Home;
+                interfaceState.settingsHomeSelection = 0;
+            }
+            return true;
+        }
+        if (interfaceState.settingsOpen) {
+            if (event == Event::Escape) {
+                if (interfaceState.settingsPage == SettingsPage::Home) {
+                    closeSettings();
+                } else {
+                    const auto pages = settingsPages();
+                    const auto found = std::find(
+                        pages.begin(), pages.end(), interfaceState.settingsPage);
+                    interfaceState.settingsHomeSelection = found == pages.end()
+                        ? 0
+                        : static_cast<size_t>(std::distance(pages.begin(), found));
+                    interfaceState.settingsPage = SettingsPage::Home;
+                }
+                return true;
+            }
+
+            if (interfaceState.settingsPage == SettingsPage::Home) {
+                const auto pages = settingsPages();
+                if (event == Event::ArrowUp || event == Event::ArrowDown) {
+                    const int direction = event == Event::ArrowDown ? 1 : -1;
+                    const int count = static_cast<int>(pages.size());
+                    interfaceState.settingsHomeSelection = static_cast<size_t>(
+                        (static_cast<int>(interfaceState.settingsHomeSelection) +
+                            direction + count) % count);
+                    return true;
+                }
+                if (event == Event::Return && !pages.empty()) {
+                    interfaceState.settingsPage = pages[std::min(
+                        interfaceState.settingsHomeSelection, pages.size() - 1)];
+                    return true;
+                }
+                for (size_t index = 0; index < pages.size(); ++index) {
+                    if (event == Event::Character(
+                            static_cast<char>('1' + index))) {
+                        interfaceState.settingsPage = pages[index];
+                        interfaceState.settingsHomeSelection = index;
+                        return true;
+                    }
+                }
+                return true;
+            }
+
+            const auto& pageSettings = settingsForPage(interfaceState.settingsPage);
+            size_t& selected = settingsSelection(interfaceState);
+            if (!pageSettings.empty()) {
+                selected = std::min(selected, pageSettings.size() - 1);
+            }
+            if ((event == Event::ArrowUp || event == Event::ArrowDown) &&
+                !pageSettings.empty()) {
+                const int direction = event == Event::ArrowDown ? 1 : -1;
+                const int count = static_cast<int>(pageSettings.size());
+                selected = static_cast<size_t>(
+                    (static_cast<int>(selected) + direction + count) % count);
+                return true;
+            }
+            if (!pageSettings.empty() &&
+                (event == Event::ArrowLeft || event == Event::ArrowRight ||
+                 event == Event::Return)) {
+                const int direction = event == Event::ArrowLeft ? -1 : 1;
+                if (adjustSetting(
+                        interfaceState.settings,
+                        pageSettings[selected].id,
+                        direction)) {
+                    persistSettings();
+                }
+                return true;
+            }
+            if (!pageSettings.empty() && event == Event::Backspace) {
+                if (resetSetting(interfaceState.settings, pageSettings[selected].id)) {
+                    persistSettings();
+                }
+                return true;
+            }
+            return true;
+        }
+        if (event == Event::Escape) {
             running.store(false);
             exitLoop();
             return true;
@@ -398,9 +975,24 @@ int runInteractive(std::unique_ptr<Prism::Capture::SystemAudioCapture> capture,
             resetRequested.store(true);
             return true;
         }
+        if (event == Event::Character('v')) {
+            adjustSetting(
+                interfaceState.settings, SettingId::VectorscopeMode, 1);
+            persistSettings();
+            return true;
+        }
         if (event == Event::Tab || event == Event::TabReverse) {
+            const auto navigationLayout = buildDashboardLayout(
+                screen.dimx(),
+                screen.dimy(),
+                interfaceState.settings.layoutPreset,
+                interfaceState.expandedPanel);
+            const auto navigationPanels = interfaceState.expandedPanel
+                ? panelOrder()
+                : visiblePanelOrder(navigationLayout);
             interfaceState.focusedPanel = nextPanel(
                 interfaceState.focusedPanel,
+                navigationPanels,
                 event == Event::TabReverse);
             if (interfaceState.expandedPanel) {
                 interfaceState.expandedPanel = interfaceState.focusedPanel;
@@ -416,16 +1008,34 @@ int runInteractive(std::unique_ptr<Prism::Capture::SystemAudioCapture> capture,
             return true;
         }
         if (event == Event::Character('l')) {
-            interfaceState.layoutPreset = nextLayoutPreset(interfaceState.layoutPreset);
+            adjustSetting(interfaceState.settings, SettingId::Layout, 1);
+            persistSettings();
             interfaceState.expandedPanel.reset();
+            const auto nextLayout = buildDashboardLayout(
+                screen.dimx(), screen.dimy(), interfaceState.settings.layoutPreset);
+            if (!layoutContainsPanel(nextLayout, interfaceState.focusedPanel)) {
+                const auto visible = visiblePanelOrder(nextLayout);
+                if (!visible.empty()) {
+                    interfaceState.focusedPanel = visible.front();
+                }
+            }
             return true;
         }
-        if (event == Event::Character('1') || event == Event::Character('2')) {
-            interfaceState.focusedPanel = event == Event::Character('1')
-                ? PanelId::Spectrum
-                : PanelId::Levels;
+        std::optional<PanelId> selectedPanel;
+        if (event == Event::Character('1')) selectedPanel = PanelId::Spectrum;
+        if (event == Event::Character('2')) selectedPanel = PanelId::Oscilloscope;
+        if (event == Event::Character('3')) selectedPanel = PanelId::Vectorscope;
+        if (event == Event::Character('4')) selectedPanel = PanelId::Levels;
+        if (selectedPanel) {
+            interfaceState.focusedPanel = *selectedPanel;
             if (interfaceState.expandedPanel) {
                 interfaceState.expandedPanel = interfaceState.focusedPanel;
+            } else {
+                const auto currentLayout = buildDashboardLayout(
+                    screen.dimx(), screen.dimy(), interfaceState.settings.layoutPreset);
+                if (!layoutContainsPanel(currentLayout, interfaceState.focusedPanel)) {
+                    interfaceState.expandedPanel = interfaceState.focusedPanel;
+                }
             }
             return true;
         }

tui/src/tui_settings.cpp

@@ -0,0 +1,409 @@
+#include "tui_settings.h"
+
+#include <algorithm>
+#include <cmath>
+#include <cstdlib>
+#include <fstream>
+#include <iomanip>
+#include <sstream>
+#include <system_error>
+
+namespace Prism::Tui {
+namespace {
+
+const std::vector<SettingDescriptor> kGeneralSettings = {
+    {SettingId::InputTrim, "Input trim", "Applies gain before every analyzer."},
+    {SettingId::RefreshRate, "Refresh rate", "Controls how often the terminal display is published."},
+    {SettingId::Layout, "Dashboard layout", "Chooses automatic, stacked, or column panes."},
+};
+
+const std::vector<SettingDescriptor> kSpectrumSettings = {
+    {SettingId::SpectrumPeakReadout, "Peak readout", "Shows the strongest stable spectral peak in the panel title."},
+    {SettingId::SpectrumTilt, "Display tilt", "Offsets the spectrum by decibels per octave around 1 kHz."},
+};
+
+const std::vector<SettingDescriptor> kOscilloscopeSettings = {
+    {SettingId::OscilloscopePitchLock, "Pitch lock", "Stabilizes the waveform around its detected fundamental."},
+    {SettingId::OscilloscopeFrequencyReadout, "Frequency readout", "Shows the live detected fundamental while pitch lock is enabled."},
+    {SettingId::OscilloscopeTraceWeight, "Trace weight", "Changes the thickness of the oscilloscope trace."},
+};
+
+const std::vector<SettingDescriptor> kVectorscopeSettings = {
+    {SettingId::VectorscopeMode, "Display mode", "Changes the stereo projection used by the vectorscope."},
+    {SettingId::VectorscopeGuides, "Guides", "Shows the mode-specific reference contours and axes."},
+    {SettingId::VectorscopeDetail, "Point detail", "Balances point density against terminal rendering cost."},
+};
+
+float snap(float value, float step) {
+    return std::round(value / step) * step;
+}
+
+std::string boolValue(bool enabled) {
+    return enabled ? "● On" : "○ Off";
+}
+
+std::string trimFloat(float value, int precision) {
+    std::ostringstream output;
+    output << std::fixed << std::setprecision(precision) << value;
+    return output.str();
+}
+
+std::string serializeLayout(LayoutPreset layout) {
+    return layoutPresetName(layout);
+}
+
+std::string serializeVectorMode(VectorscopeMode mode) {
+    switch (mode) {
+        case VectorscopeMode::Lissajous: return "lissajous";
+        case VectorscopeMode::PolarUnipolar: return "polar_unipolar";
+        case VectorscopeMode::PolarBipolar: return "polar_bipolar";
+        case VectorscopeMode::LinearUnipolar: return "linear_unipolar";
+        case VectorscopeMode::LinearBipolar: return "linear_bipolar";
+    }
+    return "lissajous";
+}
+
+std::string serializeVectorDetail(VectorscopeDetail detail) {
+    switch (detail) {
+        case VectorscopeDetail::Balanced: return "balanced";
+        case VectorscopeDetail::Detailed: return "detailed";
+        case VectorscopeDetail::Maximum: return "maximum";
+    }
+    return "detailed";
+}
+
+bool parseBool(const std::string& value, bool fallback) {
+    if (value == "true" || value == "1" || value == "on") return true;
+    if (value == "false" || value == "0" || value == "off") return false;
+    return fallback;
+}
+
+float parseFloat(const std::string& value, float fallback) {
+    try {
+        size_t consumed = 0;
+        const float parsed = std::stof(value, &consumed);
+        return consumed == value.size() && std::isfinite(parsed) ? parsed : fallback;
+    } catch (...) {
+        return fallback;
+    }
+}
+
+int parseInt(const std::string& value, int fallback) {
+    try {
+        size_t consumed = 0;
+        const int parsed = std::stoi(value, &consumed);
+        return consumed == value.size() ? parsed : fallback;
+    } catch (...) {
+        return fallback;
+    }
+}
+
+LayoutPreset parseLayout(const std::string& value, LayoutPreset fallback) {
+    if (value == "auto") return LayoutPreset::Automatic;
+    if (value == "stacked") return LayoutPreset::Stacked;
+    if (value == "columns") return LayoutPreset::Columns;
+    return fallback;
+}
+
+VectorscopeMode parseVectorMode(const std::string& value, VectorscopeMode fallback) {
+    if (value == "lissajous") return VectorscopeMode::Lissajous;
+    if (value == "polar_unipolar") return VectorscopeMode::PolarUnipolar;
+    if (value == "polar_bipolar") return VectorscopeMode::PolarBipolar;
+    if (value == "linear_unipolar") return VectorscopeMode::LinearUnipolar;
+    if (value == "linear_bipolar") return VectorscopeMode::LinearBipolar;
+    return fallback;
+}
+
+VectorscopeDetail parseVectorDetail(const std::string& value,
+                                    VectorscopeDetail fallback) {
+    if (value == "balanced") return VectorscopeDetail::Balanced;
+    if (value == "detailed") return VectorscopeDetail::Detailed;
+    if (value == "maximum") return VectorscopeDetail::Maximum;
+    return fallback;
+}
+
+const char* environmentValue(const char* name) {
+    const char* value = std::getenv(name);
+    return value != nullptr && value[0] != '\0' ? value : nullptr;
+}
+
+}  // namespace
+
+TuiSettings normalizeSettings(TuiSettings settings) {
+    settings.inputTrimDb = std::clamp(snap(settings.inputTrimDb, 0.5f), -12.0f, 12.0f);
+    settings.refreshRate = settings.refreshRate <= 30 ? 30 : 60;
+    settings.spectrumTiltDbPerOctave = std::clamp(
+        snap(settings.spectrumTiltDbPerOctave, 0.1f), -2.0f, 8.0f);
+    settings.oscilloscopeTraceWeight = std::clamp(settings.oscilloscopeTraceWeight, 1, 3);
+    if (!settings.oscilloscopePitchLock) {
+        settings.oscilloscopeFrequencyReadout = false;
+    }
+    return settings;
+}
+
+bool operator==(const TuiSettings& left, const TuiSettings& right) {
+    return left.inputTrimDb == right.inputTrimDb &&
+        left.refreshRate == right.refreshRate &&
+        left.layoutPreset == right.layoutPreset &&
+        left.spectrumPeakReadout == right.spectrumPeakReadout &&
+        left.spectrumTiltDbPerOctave == right.spectrumTiltDbPerOctave &&
+        left.oscilloscopePitchLock == right.oscilloscopePitchLock &&
+        left.oscilloscopeFrequencyReadout == right.oscilloscopeFrequencyReadout &&
+        left.oscilloscopeTraceWeight == right.oscilloscopeTraceWeight &&
+        left.vectorscopeMode == right.vectorscopeMode &&
+        left.vectorscopeGuides == right.vectorscopeGuides &&
+        left.vectorscopeDetail == right.vectorscopeDetail;
+}
+
+bool operator!=(const TuiSettings& left, const TuiSettings& right) {
+    return !(left == right);
+}
+
+std::vector<SettingsPage> settingsPages() {
+    return {
+        SettingsPage::General,
+        SettingsPage::Spectrum,
+        SettingsPage::Oscilloscope,
+        SettingsPage::Vectorscope,
+    };
+}
+
+const char* settingsPageName(SettingsPage page) {
+    switch (page) {
+        case SettingsPage::Home: return "Settings";
+        case SettingsPage::General: return "General";
+        case SettingsPage::Spectrum: return "Spectrum";
+        case SettingsPage::Oscilloscope: return "Oscilloscope";
+        case SettingsPage::Vectorscope: return "Vectorscope";
+    }
+    return "Settings";
+}
+
+const char* settingsPageDescription(SettingsPage page) {
+    switch (page) {
+        case SettingsPage::Home: return "Choose a section.";
+        case SettingsPage::General: return "Audio input and dashboard behavior.";
+        case SettingsPage::Spectrum: return "Frequency analysis and readouts.";
+        case SettingsPage::Oscilloscope: return "Waveform stabilization and presentation.";
+        case SettingsPage::Vectorscope: return "Stereo projection and point rendering.";
+    }
+    return {};
+}
+
+const std::vector<SettingDescriptor>& settingsForPage(SettingsPage page) {
+    switch (page) {
+        case SettingsPage::General: return kGeneralSettings;
+        case SettingsPage::Spectrum: return kSpectrumSettings;
+        case SettingsPage::Oscilloscope: return kOscilloscopeSettings;
+        case SettingsPage::Vectorscope: return kVectorscopeSettings;
+        case SettingsPage::Home: break;
+    }
+    static const std::vector<SettingDescriptor> empty;
+    return empty;
+}
+
+std::string settingValue(const TuiSettings& settings, SettingId setting) {
+    switch (setting) {
+        case SettingId::InputTrim:
+            return (settings.inputTrimDb > 0.0f ? "+" : "") +
+                trimFloat(settings.inputTrimDb, 1) + " dB";
+        case SettingId::RefreshRate:
+            return std::to_string(settings.refreshRate) + " FPS";
+        case SettingId::Layout:
+            return layoutPresetName(settings.layoutPreset);
+        case SettingId::SpectrumPeakReadout:
+            return boolValue(settings.spectrumPeakReadout);
+        case SettingId::SpectrumTilt:
+            return trimFloat(settings.spectrumTiltDbPerOctave, 1) + " dB/oct";
+        case SettingId::OscilloscopePitchLock:
+            return boolValue(settings.oscilloscopePitchLock);
+        case SettingId::OscilloscopeFrequencyReadout:
+            return boolValue(settings.oscilloscopeFrequencyReadout);
+        case SettingId::OscilloscopeTraceWeight:
+            return std::to_string(settings.oscilloscopeTraceWeight);
+        case SettingId::VectorscopeMode:
+            return vectorscopeModeName(settings.vectorscopeMode);
+        case SettingId::VectorscopeGuides:
+            return boolValue(settings.vectorscopeGuides);
+        case SettingId::VectorscopeDetail:
+            switch (settings.vectorscopeDetail) {
+                case VectorscopeDetail::Balanced: return "Balanced";
+                case VectorscopeDetail::Detailed: return "Detailed";
+                case VectorscopeDetail::Maximum: return "Maximum";
+            }
+    }
+    return {};
+}
+
+bool settingIsBoolean(SettingId setting) {
+    return setting == SettingId::SpectrumPeakReadout ||
+        setting == SettingId::OscilloscopePitchLock ||
+        setting == SettingId::OscilloscopeFrequencyReadout ||
+        setting == SettingId::VectorscopeGuides;
+}
+
+bool adjustSetting(TuiSettings& settings, SettingId setting, int direction) {
+    if (direction == 0) return false;
+    const TuiSettings before = settings;
+    switch (setting) {
+        case SettingId::InputTrim:
+            settings.inputTrimDb += direction > 0 ? 0.5f : -0.5f;
+            break;
+        case SettingId::RefreshRate:
+            settings.refreshRate = settings.refreshRate == 60 ? 30 : 60;
+            break;
+        case SettingId::Layout:
+            if (direction > 0) {
+                settings.layoutPreset = nextLayoutPreset(settings.layoutPreset);
+            } else {
+                settings.layoutPreset = settings.layoutPreset == LayoutPreset::Automatic
+                    ? LayoutPreset::Columns
+                    : settings.layoutPreset == LayoutPreset::Columns
+                        ? LayoutPreset::Stacked
+                        : LayoutPreset::Automatic;
+            }
+            break;
+        case SettingId::SpectrumPeakReadout:
+            settings.spectrumPeakReadout = !settings.spectrumPeakReadout;
+            break;
+        case SettingId::SpectrumTilt:
+            settings.spectrumTiltDbPerOctave += direction > 0 ? 0.1f : -0.1f;
+            break;
+        case SettingId::OscilloscopePitchLock:
+            settings.oscilloscopePitchLock = !settings.oscilloscopePitchLock;
+            if (!settings.oscilloscopePitchLock) {
+                settings.oscilloscopeFrequencyReadout = false;
+            }
+            break;
+        case SettingId::OscilloscopeFrequencyReadout:
+            if (!settings.oscilloscopePitchLock) {
+                return false;
+            }
+            settings.oscilloscopeFrequencyReadout = !settings.oscilloscopeFrequencyReadout;
+            break;
+        case SettingId::OscilloscopeTraceWeight:
+            settings.oscilloscopeTraceWeight += direction > 0 ? 1 : -1;
+            break;
+        case SettingId::VectorscopeMode:
+            if (direction > 0) {
+                settings.vectorscopeMode = nextVectorscopeMode(settings.vectorscopeMode);
+            } else {
+                for (int index = 0; index < 4; ++index) {
+                    settings.vectorscopeMode = nextVectorscopeMode(settings.vectorscopeMode);
+                }
+            }
+            break;
+        case SettingId::VectorscopeGuides:
+            settings.vectorscopeGuides = !settings.vectorscopeGuides;
+            break;
+        case SettingId::VectorscopeDetail: {
+            int value = static_cast<int>(settings.vectorscopeDetail);
+            value = std::clamp(value + (direction > 0 ? 1 : -1), 0, 2);
+            settings.vectorscopeDetail = static_cast<VectorscopeDetail>(value);
+            break;
+        }
+    }
+    settings = normalizeSettings(settings);
+    return settings != before;
+}
+
+bool resetSetting(TuiSettings& settings, SettingId setting) {
+    const TuiSettings defaults;
+    const TuiSettings before = settings;
+    switch (setting) {
+        case SettingId::InputTrim: settings.inputTrimDb = defaults.inputTrimDb; break;
+        case SettingId::RefreshRate: settings.refreshRate = defaults.refreshRate; break;
+        case SettingId::Layout: settings.layoutPreset = defaults.layoutPreset; break;
+        case SettingId::SpectrumPeakReadout: settings.spectrumPeakReadout = defaults.spectrumPeakReadout; break;
+        case SettingId::SpectrumTilt: settings.spectrumTiltDbPerOctave = defaults.spectrumTiltDbPerOctave; break;
+        case SettingId::OscilloscopePitchLock: settings.oscilloscopePitchLock = defaults.oscilloscopePitchLock; break;
+        case SettingId::OscilloscopeFrequencyReadout: settings.oscilloscopeFrequencyReadout = defaults.oscilloscopeFrequencyReadout; break;
+        case SettingId::OscilloscopeTraceWeight: settings.oscilloscopeTraceWeight = defaults.oscilloscopeTraceWeight; break;
+        case SettingId::VectorscopeMode: settings.vectorscopeMode = defaults.vectorscopeMode; break;
+        case SettingId::VectorscopeGuides: settings.vectorscopeGuides = defaults.vectorscopeGuides; break;
+        case SettingId::VectorscopeDetail: settings.vectorscopeDetail = defaults.vectorscopeDetail; break;
+    }
+    return settings != before;
+}
+
+std::filesystem::path defaultSettingsPath() {
+#if defined(_WIN32)
+    if (const char* appData = environmentValue("APPDATA")) {
+        return std::filesystem::path(appData) / "Prism" / "tui.conf";
+    }
+#elif defined(__APPLE__)
+    if (const char* home = environmentValue("HOME")) {
+        return std::filesystem::path(home) /
+            "Library" / "Application Support" / "Prism" / "tui.conf";
+    }
+#else
+    if (const char* xdgConfig = environmentValue("XDG_CONFIG_HOME")) {
+        return std::filesystem::path(xdgConfig) / "prism" / "tui.conf";
+    }
+    if (const char* home = environmentValue("HOME")) {
+        return std::filesystem::path(home) / ".config" / "prism" / "tui.conf";
+    }
+#endif
+    return std::filesystem::path("prism-tui.conf");
+}
+
+TuiSettings loadSettings(const std::filesystem::path& path) {
+    TuiSettings settings;
+    std::ifstream input(path);
+    std::string line;
+    while (std::getline(input, line)) {
+        const size_t separator = line.find('=');
+        if (separator == std::string::npos) continue;
+        const std::string key = line.substr(0, separator);
+        const std::string value = line.substr(separator + 1);
+        if (key == "input_trim_db") settings.inputTrimDb = parseFloat(value, settings.inputTrimDb);
+        else if (key == "refresh_rate") settings.refreshRate = parseInt(value, settings.refreshRate);
+        else if (key == "layout") settings.layoutPreset = parseLayout(value, settings.layoutPreset);
+        else if (key == "spectrum_peak") settings.spectrumPeakReadout = parseBool(value, settings.spectrumPeakReadout);
+        else if (key == "spectrum_tilt") settings.spectrumTiltDbPerOctave = parseFloat(value, settings.spectrumTiltDbPerOctave);
+        else if (key == "osc_pitch_lock") settings.oscilloscopePitchLock = parseBool(value, settings.oscilloscopePitchLock);
+        else if (key == "osc_frequency") settings.oscilloscopeFrequencyReadout = parseBool(value, settings.oscilloscopeFrequencyReadout);
+        else if (key == "osc_trace_weight") settings.oscilloscopeTraceWeight = parseInt(value, settings.oscilloscopeTraceWeight);
+        else if (key == "vector_mode") settings.vectorscopeMode = parseVectorMode(value, settings.vectorscopeMode);
+        else if (key == "vector_guides") settings.vectorscopeGuides = parseBool(value, settings.vectorscopeGuides);
+        else if (key == "vector_detail") settings.vectorscopeDetail = parseVectorDetail(value, settings.vectorscopeDetail);
+    }
+    return normalizeSettings(settings);
+}
+
+bool saveSettings(const TuiSettings& rawSettings,
+                  const std::filesystem::path& path,
+                  std::string* error) {
+    const TuiSettings settings = normalizeSettings(rawSettings);
+    std::error_code filesystemError;
+    if (!path.parent_path().empty()) {
+        std::filesystem::create_directories(path.parent_path(), filesystemError);
+        if (filesystemError) {
+            if (error) *error = filesystemError.message();
+            return false;
+        }
+    }
+    std::ofstream output(path, std::ios::trunc);
+    if (!output) {
+        if (error) *error = "could not open settings file";
+        return false;
+    }
+    output << "input_trim_db=" << settings.inputTrimDb << '\n'
+           << "refresh_rate=" << settings.refreshRate << '\n'
+           << "layout=" << serializeLayout(settings.layoutPreset) << '\n'
+           << "spectrum_peak=" << (settings.spectrumPeakReadout ? "true" : "false") << '\n'
+           << "spectrum_tilt=" << settings.spectrumTiltDbPerOctave << '\n'
+           << "osc_pitch_lock=" << (settings.oscilloscopePitchLock ? "true" : "false") << '\n'
+           << "osc_frequency=" << (settings.oscilloscopeFrequencyReadout ? "true" : "false") << '\n'
+           << "osc_trace_weight=" << settings.oscilloscopeTraceWeight << '\n'
+           << "vector_mode=" << serializeVectorMode(settings.vectorscopeMode) << '\n'
+           << "vector_guides=" << (settings.vectorscopeGuides ? "true" : "false") << '\n'
+           << "vector_detail=" << serializeVectorDetail(settings.vectorscopeDetail) << '\n';
+    if (!output) {
+        if (error) *error = "could not write settings file";
+        return false;
+    }
+    return true;
+}
+
+}  // namespace Prism::Tui

tui/src/tui_settings.h

@@ -0,0 +1,80 @@
+#pragma once
+
+#include "dashboard_layout.h"
+#include "scope_plot_model.h"
+
+#include <filesystem>
+#include <string>
+#include <vector>
+
+namespace Prism::Tui {
+
+enum class SettingsPage {
+    Home,
+    General,
+    Spectrum,
+    Oscilloscope,
+    Vectorscope,
+};
+
+enum class SettingId {
+    InputTrim,
+    RefreshRate,
+    Layout,
+    SpectrumPeakReadout,
+    SpectrumTilt,
+    OscilloscopePitchLock,
+    OscilloscopeFrequencyReadout,
+    OscilloscopeTraceWeight,
+    VectorscopeMode,
+    VectorscopeGuides,
+    VectorscopeDetail,
+};
+
+enum class VectorscopeDetail {
+    Balanced,
+    Detailed,
+    Maximum,
+};
+
+struct TuiSettings {
+    float inputTrimDb = 0.0f;
+    int refreshRate = 60;
+    LayoutPreset layoutPreset = LayoutPreset::Automatic;
+    bool spectrumPeakReadout = true;
+    float spectrumTiltDbPerOctave = 2.0f;
+    bool oscilloscopePitchLock = true;
+    bool oscilloscopeFrequencyReadout = true;
+    int oscilloscopeTraceWeight = 2;
+    VectorscopeMode vectorscopeMode = VectorscopeMode::Lissajous;
+    bool vectorscopeGuides = true;
+    VectorscopeDetail vectorscopeDetail = VectorscopeDetail::Detailed;
+};
+
+struct SettingDescriptor {
+    SettingId id;
+    const char* name;
+    const char* description;
+};
+
+TuiSettings normalizeSettings(TuiSettings settings);
+bool operator==(const TuiSettings& left, const TuiSettings& right);
+bool operator!=(const TuiSettings& left, const TuiSettings& right);
+
+std::vector<SettingsPage> settingsPages();
+const char* settingsPageName(SettingsPage page);
+const char* settingsPageDescription(SettingsPage page);
+const std::vector<SettingDescriptor>& settingsForPage(SettingsPage page);
+
+std::string settingValue(const TuiSettings& settings, SettingId setting);
+bool settingIsBoolean(SettingId setting);
+bool adjustSetting(TuiSettings& settings, SettingId setting, int direction);
+bool resetSetting(TuiSettings& settings, SettingId setting);
+
+std::filesystem::path defaultSettingsPath();
+TuiSettings loadSettings(const std::filesystem::path& path);
+bool saveSettings(const TuiSettings& settings,
+                  const std::filesystem::path& path,
+                  std::string* error = nullptr);
+
+}  // namespace Prism::Tui

tui/test/tui_tests.cpp

@@ -2,13 +2,17 @@
 #include "cli.h"
 #include "dashboard_layout.h"
 #include "display_model.h"
+#include "scope_plot_model.h"
 #include "snapshot_store.h"
+#include "spectrum_peak_model.h"
 #include "system_audio_capture.h"
+#include "tui_settings.h"
 
 #include <algorithm>
 #include <cmath>
 #include <cstdlib>
 #include <deque>
+#include <filesystem>
 #include <iostream>
 #include <memory>
 #include <string>
@@ -107,6 +111,8 @@ void testCli() {
         "exclusive commands should not combine");
     require(Prism::Tui::usageText().find("Tab / Shift-Tab") != std::string::npos,
         "help should describe dashboard keyboard controls");
+    require(Prism::Tui::usageText().find("Cycle vectorscope") != std::string::npos,
+        "help should describe vectorscope mode controls");
 }
 
 void testProjectionAndLayout() {
@@ -149,13 +155,23 @@ void testProjectionAndLayout() {
     require(!wide.terminalTooSmall &&
         wide.resolvedPreset == Prism::Tui::LayoutPreset::Columns,
         "wide, tall terminals should use the columns dashboard");
-    require(wide.panels.size() == 2 &&
-        wide.panels[0].width + wide.panels[1].width == 100 &&
-        wide.panels[0].width > wide.panels[1].width,
-        "column panels should fill the width and favor the spectrum");
+    require(wide.panels.size() == 4 &&
+        wide.panels[0].panel == Prism::Tui::PanelId::Spectrum &&
+        wide.panels[1].panel == Prism::Tui::PanelId::Oscilloscope &&
+        wide.panels[2].panel == Prism::Tui::PanelId::Vectorscope &&
+        wide.panels[3].panel == Prism::Tui::PanelId::Levels,
+        "the dashboard should contain all four scope panels");
+    require(wide.panels[0].width == wide.panels[1].width &&
+        wide.panels[2].width == wide.panels[3].width &&
+        wide.panels[0].width + wide.panels[2].width == 100 &&
+        wide.panels[0].width > wide.panels[2].width,
+        "dashboard columns should fill the width and favor visual plots");
+    require(wide.panels[0].height + wide.panels[1].height == 28 &&
+        wide.panels[2].height + wide.panels[3].height == 28,
+        "both dashboard columns should fill the available height");
 
     const auto stacked = Prism::Tui::buildDashboardLayout(
-        80, 20, Prism::Tui::LayoutPreset::Automatic);
+        60, 20, Prism::Tui::LayoutPreset::Automatic);
     require(stacked.resolvedPreset == Prism::Tui::LayoutPreset::Stacked,
         "short terminals should stack their panels");
     require(stacked.panels.size() == 2 &&
@@ -182,11 +198,250 @@ void testProjectionAndLayout() {
         expanded.panels[0].width == 100 && expanded.panels[0].height == 28,
         "expanded panels should occupy the complete dashboard area");
     require(Prism::Tui::nextPanel(Prism::Tui::PanelId::Spectrum) ==
-        Prism::Tui::PanelId::Levels,
+        Prism::Tui::PanelId::Oscilloscope,
         "panel focus should cycle forward");
     require(Prism::Tui::nextPanel(Prism::Tui::PanelId::Spectrum, true) ==
         Prism::Tui::PanelId::Levels,
         "panel focus should cycle backward");
+    const auto compactPanels = Prism::Tui::visiblePanelOrder(stacked);
+    require(compactPanels.size() == 2 &&
+        Prism::Tui::nextPanel(
+            Prism::Tui::PanelId::Spectrum, compactPanels) == Prism::Tui::PanelId::Levels,
+        "compact layout focus should skip hidden visual scopes");
+}
+
+void testSpectrumPeakModel() {
+    constexpr float sampleRate = 48000.0f;
+    constexpr size_t fftSize = 4096;
+    const float targetBin = 440.0f * static_cast<float>(fftSize) / sampleRate;
+    std::vector<float> magnitudes(fftSize / 2, -100.0f);
+    for (size_t bin = 1; bin + 1 < magnitudes.size(); ++bin) {
+        const float distance = static_cast<float>(bin) - targetBin;
+        magnitudes[bin] = std::max(-100.0f, -12.0f - 4.0f * distance * distance);
+    }
+
+    Prism::Tui::SpectrumPeakTracker tracker;
+    const auto peak = tracker.select(magnitudes, sampleRate, fftSize, 2.0f);
+    require(peak.has_value(), "a deterministic spectral peak should be detected");
+    require(std::abs(peak->frequencyHz - 440.0f) < 1.0f,
+        "quadratic peak interpolation should recover sub-bin frequency");
+    require(std::abs(peak->dbfs + 12.0f) < 0.1f,
+        "peak readout should preserve the untilted dBFS value");
+    require(peak->pitch.find("A4") == 0,
+        "peak readout should include its musical pitch");
+    require(Prism::Tui::formatSpectrumPitch(261.6256f).find("C4") == 0,
+        "pitch formatting should use conventional note and octave names");
+
+    tracker.reset();
+    std::fill(magnitudes.begin(), magnitudes.end(), -100.0f);
+    require(!tracker.select(magnitudes, sampleRate, fftSize, 2.0f),
+        "silent spectra should not produce a peak readout");
+}
+
+void testSettingsModelAndPersistence() {
+    Prism::Tui::TuiSettings settings;
+    settings.inputTrimDb = 30.0f;
+    settings.refreshRate = 42;
+    settings.spectrumTiltDbPerOctave = -8.0f;
+    settings.oscilloscopeTraceWeight = 20;
+    settings = Prism::Tui::normalizeSettings(settings);
+    require(settings.inputTrimDb == 12.0f && settings.refreshRate == 60 &&
+        settings.spectrumTiltDbPerOctave == -2.0f &&
+        settings.oscilloscopeTraceWeight == 3,
+        "settings normalization should enforce public ranges");
+
+    const auto pages = Prism::Tui::settingsPages();
+    require(pages.size() == 4 &&
+        Prism::Tui::settingsForPage(Prism::Tui::SettingsPage::General).size() == 3,
+        "settings should expose shallow category pages");
+    Prism::Tui::TuiSettings adjusted;
+    require(Prism::Tui::adjustSetting(
+        adjusted, Prism::Tui::SettingId::InputTrim, 1) &&
+        adjusted.inputTrimDb == 0.5f,
+        "numeric settings should adjust by their documented step");
+    require(Prism::Tui::adjustSetting(
+        adjusted, Prism::Tui::SettingId::SpectrumPeakReadout, 1) &&
+        !adjusted.spectrumPeakReadout,
+        "boolean settings should toggle directly");
+    require(Prism::Tui::adjustSetting(
+        adjusted, Prism::Tui::SettingId::OscilloscopePitchLock, 1) &&
+        !adjusted.oscilloscopePitchLock &&
+        !adjusted.oscilloscopeFrequencyReadout,
+        "disabling pitch lock should also disable its frequency readout");
+    require(!Prism::Tui::adjustSetting(
+        adjusted, Prism::Tui::SettingId::OscilloscopeFrequencyReadout, 1) &&
+        !adjusted.oscilloscopeFrequencyReadout,
+        "frequency readout should remain unavailable without pitch lock");
+    require(Prism::Tui::adjustSetting(
+        adjusted, Prism::Tui::SettingId::OscilloscopePitchLock, 1) &&
+        adjusted.oscilloscopePitchLock,
+        "pitch lock should remain independently re-enableable");
+    require(Prism::Tui::resetSetting(
+        adjusted, Prism::Tui::SettingId::InputTrim) &&
+        adjusted.inputTrimDb == 0.0f,
+        "individual settings should reset to defaults");
+
+    const auto settingsPath = std::filesystem::temp_directory_path() /
+        "prism-tui-settings-test.conf";
+    std::error_code ignored;
+    std::filesystem::remove(settingsPath, ignored);
+    adjusted.layoutPreset = Prism::Tui::LayoutPreset::Columns;
+    adjusted.vectorscopeMode = Prism::Tui::VectorscopeMode::PolarBipolar;
+    adjusted.vectorscopeDetail = Prism::Tui::VectorscopeDetail::Maximum;
+    std::string error;
+    require(Prism::Tui::saveSettings(adjusted, settingsPath, &error),
+        "settings should persist to a TUI-specific configuration file");
+    require(Prism::Tui::loadSettings(settingsPath) == adjusted,
+        "persisted settings should round-trip without changing values");
+    std::filesystem::remove(settingsPath, ignored);
+}
+
+void testScopePlotModels() {
+    const auto oscilloscope = Prism::Tui::buildOscilloscopePlot(
+        {-1.0f, 0.0f, 1.0f}, 9, 9);
+    require(oscilloscope.size() == 9,
+        "oscilloscope projection should fill every Braille pixel column");
+    require(oscilloscope.front().y == 8 && oscilloscope.back().y == 0,
+        "oscilloscope projection should preserve full-scale polarity");
+    require(std::all_of(
+        oscilloscope.begin(), oscilloscope.end(), [](const Prism::Tui::PlotPoint& point) {
+            return point.x >= 0 && point.x < 9 && point.y >= 0 && point.y < 9;
+        }), "oscilloscope projection should remain bounded");
+    const auto zeroLine = Prism::Tui::buildOscilloscopePlot({0.0f}, 1, 8);
+    require(zeroLine.front().y == Prism::Tui::oscilloscopeZeroY(8) &&
+        zeroLine.front().y == 4,
+        "the oscilloscope zero line should use the waveform's center rounding");
+
+    const std::vector<float> multiband = {
+        1.0f, 0.0f,
+        0.0f, 0.5f,
+        -1.0f, -0.5f,
+    };
+    const auto vectorscope = Prism::Tui::buildVectorscopePlot(
+        multiband, 1, 21, 21);
+    require(vectorscope[0].size() == 1 &&
+        vectorscope[1].size() == 1 &&
+        vectorscope[2].size() == 1,
+        "vectorscope projection should preserve all three frequency bands");
+    for (const auto& band : vectorscope) {
+        require(std::all_of(
+            band.begin(), band.end(), [](const Prism::Tui::PlotPoint& point) {
+                return point.x >= 0 && point.x < 21 && point.y >= 0 && point.y < 21;
+            }), "vectorscope projection should remain bounded");
+    }
+    require(Prism::Tui::buildOscilloscopePlot({}, 10, 10).empty(),
+        "an empty oscilloscope frame should render no points");
+
+    auto mode = Prism::Tui::VectorscopeMode::Lissajous;
+    for (int index = 0; index < 5; ++index) {
+        require(std::string(Prism::Tui::vectorscopeModeName(mode)).size() > 0,
+            "each vectorscope mode should have a display name");
+        mode = Prism::Tui::nextVectorscopeMode(mode);
+    }
+    require(mode == Prism::Tui::VectorscopeMode::Lissajous,
+        "vectorscope mode selection should cycle through all five modes");
+
+    const std::vector<float> correlated = {
+        0.25f, 0.25f,
+        0.25f, 0.25f,
+        0.25f, 0.25f,
+    };
+    const auto linear = Prism::Tui::buildVectorscopePlot(
+        correlated,
+        1,
+        41,
+        41,
+        Prism::Tui::VectorscopeMode::LinearBipolar);
+    const auto polar = Prism::Tui::buildVectorscopePlot(
+        correlated,
+        1,
+        41,
+        41,
+        Prism::Tui::VectorscopeMode::PolarBipolar);
+    const auto centeredLayout = Prism::Tui::getVectorscopePlotLayout(
+        41, 41, Prism::Tui::VectorscopeMode::LinearBipolar);
+    require(linear[0].front().x == centeredLayout.centerX &&
+        linear[0].front().y < centeredLayout.centerY,
+        "linear vectorscope mode should rotate correlated stereo onto the mono axis");
+    require(polar[0].front().y < linear[0].front().y,
+        "polar vectorscope mode should expand quiet points radially");
+
+    const std::vector<float> negativeMid = {
+        -0.5f, -0.5f,
+        -0.5f, -0.5f,
+        -0.5f, -0.5f,
+    };
+    const auto unipolar = Prism::Tui::buildVectorscopePlot(
+        negativeMid,
+        1,
+        41,
+        41,
+        Prism::Tui::VectorscopeMode::PolarUnipolar);
+    require(unipolar[0].empty() && unipolar[1].empty() && unipolar[2].empty(),
+        "unipolar vectorscope modes should omit negative-mid points");
+    const auto unipolarLayout = Prism::Tui::getVectorscopePlotLayout(
+        41, 41, Prism::Tui::VectorscopeMode::PolarUnipolar);
+    require(unipolarLayout.unipolar &&
+        unipolarLayout.centerY > centeredLayout.centerY,
+        "unipolar vectorscope modes should use the lower display origin");
+
+    std::vector<float> denseMultiband(300 * Visualizer::MULTIBAND_POINT_STRIDE, 0.2f);
+    const auto detailPreserving = Prism::Tui::buildVectorscopePlot(
+        denseMultiband,
+        300,
+        12,
+        12,
+        Prism::Tui::VectorscopeMode::Lissajous);
+    for (const auto& band : detailPreserving) {
+        require(band.size() <= 64,
+            "vectorscope projection should adapt its point budget to terminal resolution");
+        require(!band.empty() && band.front().intensity < band.back().intensity &&
+            band.back().intensity == 1.0f,
+            "vectorscope projection should retain chronological intensity information");
+    }
+    const auto balancedDetail = Prism::Tui::buildVectorscopePlot(
+        denseMultiband, 300, 30, 30, Prism::Tui::VectorscopeMode::Lissajous, 10);
+    const auto maximumDetail = Prism::Tui::buildVectorscopePlot(
+        denseMultiband, 300, 30, 30, Prism::Tui::VectorscopeMode::Lissajous, 3);
+    require(balancedDetail[0].size() < maximumDetail[0].size(),
+        "vectorscope detail settings should change the adaptive point budget");
+}
+
+void testPitchReadoutResponse() {
+    constexpr float sampleRate = 48000.0f;
+    Visualizer::Oscilloscope oscilloscope;
+    oscilloscope.setSampleRate(sampleRate);
+    oscilloscope.setPitchLock(true);
+
+    const auto lowTone = sineChunk(100.0f, 0.5f, 4096, sampleRate);
+    oscilloscope.pushSamples(lowTone.left.data(), lowTone.left.size());
+    for (int index = 0; index < 24; ++index) {
+        oscilloscope.process();
+    }
+
+    const auto highTone = sineChunk(400.0f, 0.5f, 4096, sampleRate);
+    oscilloscope.pushSamples(highTone.left.data(), highTone.left.size());
+    const auto locked = oscilloscope.process();
+    const float latest = oscilloscope.getLatestDetectedPitch();
+    require(latest > 0.0f &&
+        std::abs(latest - 400.0f) < std::abs(locked.detectedPitch - 400.0f),
+        "the fast pitch readout should respond before the stable trigger pitch");
+
+    Visualizer::Oscilloscope freeRunning;
+    freeRunning.setSampleRate(sampleRate);
+    freeRunning.setPitchLock(false);
+    freeRunning.setDisplaySamples(128);
+    const auto firstChunk = sineChunk(200.0f, 0.5f, 512, sampleRate);
+    freeRunning.pushSamples(firstChunk.left.data(), firstChunk.left.size());
+    const auto firstWindow = freeRunning.process();
+    require(firstWindow.triggerIndex == 384.0f,
+        "free-running oscilloscopes should show the newest complete window");
+    const auto nextChunk = sineChunk(200.0f, 0.5f, 64, sampleRate);
+    freeRunning.pushSamples(nextChunk.left.data(), nextChunk.left.size());
+    const auto nextWindow = freeRunning.process();
+    require(nextWindow.triggerIndex == 448.0f &&
+        nextWindow.triggerIndex != firstWindow.triggerIndex,
+        "free-running oscilloscope windows should advance with every audio chunk");
 }
 
 void testPipelineAndFakeCapture() {
@@ -216,6 +471,26 @@ void testPipelineAndFakeCapture() {
     const auto frame = pipeline.snapshot();
     require(frame.magnitudes.size() == Prism::Tui::kDefaultFftSize / 2,
         "the default analysis pipeline should publish the 4096-point spectrum");
+    require(frame.oscilloscope.samples.size() == 2048 &&
+        frame.oscilloscope.signalPresent,
+        "the pipeline should publish a live pitch-locked oscilloscope window");
+    require(std::isfinite(frame.oscilloscope.detectedPitch) &&
+        frame.oscilloscope.detectedPitch > 0.0f,
+        "the pipeline should publish the fast pitch readout");
+    require(std::all_of(
+        frame.oscilloscope.samples.begin(),
+        frame.oscilloscope.samples.end(),
+        [](float sample) { return std::isfinite(sample); }),
+        "oscilloscope samples should remain finite");
+    require(frame.vectorscope.pointCount == Prism::Tui::kVectorscopeDisplayPoints &&
+        frame.vectorscope.multibandPoints.size() ==
+            frame.vectorscope.pointCount * Visualizer::MULTIBAND_POINT_STRIDE,
+        "the pipeline should publish a full multiband vectorscope frame");
+    require(std::all_of(
+        frame.vectorscope.multibandPoints.begin(),
+        frame.vectorscope.multibandPoints.end(),
+        [](float sample) { return std::isfinite(sample); }),
+        "vectorscope samples should remain finite");
     require(frame.vu.barLDb > -20.0f && frame.vu.barLDb < -5.0f,
         "VU level should reflect deterministic input");
     require(std::isfinite(frame.lufs.momentaryLUFS) && frame.lufs.momentaryLUFS > -60.0f,
@@ -225,6 +500,17 @@ void testPipelineAndFakeCapture() {
     require(std::abs(frame.lufs.integratedLUFS + 12.03f) < 0.5f,
         "integrated LUFS should match the deterministic stereo tone");
 
+    Prism::Tui::AnalysisPipeline trimmedPipeline(48000.0f);
+    trimmedPipeline.setInputTrimDb(6.0f);
+    for (int index = 0; index < 20; ++index) {
+        trimmedPipeline.process(sineChunk(1000.0f, 0.25f, 2400, 48000.0f));
+    }
+    const auto trimmed = trimmedPipeline.snapshot();
+    require(std::abs((trimmed.vu.barLDb - frame.vu.barLDb) - 6.0f) < 0.35f,
+        "input trim should affect the real VU analyzer before processing");
+    require(std::abs((trimmed.lufs.momentaryLUFS - frame.lufs.momentaryLUFS) - 6.0f) < 0.35f,
+        "input trim should affect the real loudness analyzer before processing");
+
     Prism::Tui::AnalysisPipeline stereoPipeline(48000.0f);
     for (int index = 0; index < 20; ++index) {
         stereoPipeline.process(stereoSineChunk(1000.0f, 0.5f, 0.125f, 2400, 48000.0f));
@@ -235,6 +521,12 @@ void testPipelineAndFakeCapture() {
     pipeline.reset();
     const auto reset = pipeline.snapshot();
     require(reset.lufs.integratedLUFS <= -59.0f, "reset should clear integrated loudness");
+    require(!reset.oscilloscope.signalPresent,
+        "reset should clear the oscilloscope display window");
+    require(reset.oscilloscope.detectedPitch == 0.0f,
+        "reset should clear the fast pitch readout");
+    require(reset.vectorscope.pointCount == 0 && reset.vectorscope.multibandPoints.empty(),
+        "reset should clear vectorscope history");
     require(capture.stopped, "fake capture should stop cleanly");
 }
 
@@ -260,6 +552,10 @@ void testThreadSafeSnapshots() {
 int main() {
     testCli();
     testProjectionAndLayout();
+    testSpectrumPeakModel();
+    testSettingsModelAndPersistence();
+    testScopePlotModels();
+    testPitchReadoutResponse();
     testPipelineAndFakeCapture();
     testThreadSafeSnapshots();
     std::cout << "Prism TUI tests passed\n";