rewrite multiband splitter to native

native/src/waveform.cpp

@@ -0,0 +1,152 @@
+#include "waveform.h"
+#include <algorithm>
+#include <cmath>
+
+namespace Visualizer {
+
+WaveformMultibandAnalyzer::WaveformMultibandAnalyzer()
+    : sampleRate_(48000.0f)
+    , samplesPerColumn_(1)
+    , columnPos_(0)
+    , leftMin_(0.0f)
+    , leftMax_(0.0f)
+    , rightMin_(0.0f)
+    , rightMax_(0.0f)
+    , leftLowSum_(0.0f)
+    , leftMidSum_(0.0f)
+    , leftHighSum_(0.0f)
+    , rightLowSum_(0.0f)
+    , rightMidSum_(0.0f)
+    , rightHighSum_(0.0f) {
+    splitter_.configure(sampleRate_);
+}
+
+void WaveformMultibandAnalyzer::configure(float sampleRate, size_t samplesPerColumn) {
+    const float nextSampleRate = std::max(1.0f, sampleRate);
+    const size_t nextSamplesPerColumn = std::max<size_t>(1, samplesPerColumn);
+
+    if (nextSampleRate == sampleRate_ && nextSamplesPerColumn == samplesPerColumn_) {
+        return;
+    }
+
+    sampleRate_ = nextSampleRate;
+    samplesPerColumn_ = nextSamplesPerColumn;
+    splitter_.configure(sampleRate_);
+    reset();
+}
+
+const std::vector<float>& WaveformMultibandAnalyzer::processMono(const float* samples, size_t length) {
+    summaries_.clear();
+
+    for (size_t i = 0; i < length; i++) {
+        const float sample = samples[i];
+        const MultibandSample bands = splitter_.process(sample, sample);
+        accumulateLeft(sample, bands);
+
+        columnPos_++;
+        if (columnPos_ >= samplesPerColumn_) {
+            flushMonoColumn();
+            resetColumn();
+        }
+    }
+
+    return summaries_;
+}
+
+const std::vector<float>& WaveformMultibandAnalyzer::processStereo(
+    const float* left,
+    const float* right,
+    size_t length
+) {
+    summaries_.clear();
+
+    for (size_t i = 0; i < length; i++) {
+        const MultibandSample bands = splitter_.process(left[i], right[i]);
+        accumulateLeft(left[i], bands);
+        accumulateRight(right[i], bands);
+
+        columnPos_++;
+        if (columnPos_ >= samplesPerColumn_) {
+            flushStereoColumn();
+            resetColumn();
+        }
+    }
+
+    return summaries_;
+}
+
+void WaveformMultibandAnalyzer::reset() {
+    splitter_.reset();
+    summaries_.clear();
+    resetColumn();
+}
+
+void WaveformMultibandAnalyzer::resetColumn() {
+    columnPos_ = 0;
+    leftMin_ = 0.0f;
+    leftMax_ = 0.0f;
+    rightMin_ = 0.0f;
+    rightMax_ = 0.0f;
+    leftLowSum_ = 0.0f;
+    leftMidSum_ = 0.0f;
+    leftHighSum_ = 0.0f;
+    rightLowSum_ = 0.0f;
+    rightMidSum_ = 0.0f;
+    rightHighSum_ = 0.0f;
+}
+
+void WaveformMultibandAnalyzer::accumulateLeft(float sample, const MultibandSample& bands) {
+    if (columnPos_ == 0) {
+        leftMin_ = sample;
+        leftMax_ = sample;
+    } else {
+        leftMin_ = std::min(leftMin_, sample);
+        leftMax_ = std::max(leftMax_, sample);
+    }
+
+    leftLowSum_ += bands.lowL * bands.lowL;
+    leftMidSum_ += bands.midL * bands.midL;
+    leftHighSum_ += bands.highL * bands.highL;
+}
+
+void WaveformMultibandAnalyzer::accumulateRight(float sample, const MultibandSample& bands) {
+    if (columnPos_ == 0) {
+        rightMin_ = sample;
+        rightMax_ = sample;
+    } else {
+        rightMin_ = std::min(rightMin_, sample);
+        rightMax_ = std::max(rightMax_, sample);
+    }
+
+    rightLowSum_ += bands.lowR * bands.lowR;
+    rightMidSum_ += bands.midR * bands.midR;
+    rightHighSum_ += bands.highR * bands.highR;
+}
+
+void WaveformMultibandAnalyzer::flushMonoColumn() {
+    summaries_.push_back(leftMin_);
+    summaries_.push_back(leftMax_);
+    summaries_.push_back(rms(leftLowSum_));
+    summaries_.push_back(rms(leftMidSum_));
+    summaries_.push_back(rms(leftHighSum_));
+}
+
+void WaveformMultibandAnalyzer::flushStereoColumn() {
+    summaries_.push_back(leftMin_);
+    summaries_.push_back(leftMax_);
+    summaries_.push_back(rms(leftLowSum_));
+    summaries_.push_back(rms(leftMidSum_));
+    summaries_.push_back(rms(leftHighSum_));
+    summaries_.push_back(rightMin_);
+    summaries_.push_back(rightMax_);
+    summaries_.push_back(rms(rightLowSum_));
+    summaries_.push_back(rms(rightMidSum_));
+    summaries_.push_back(rms(rightHighSum_));
+}
+
+float WaveformMultibandAnalyzer::rms(float sum) const {
+    const size_t count = std::max<size_t>(1, columnPos_);
+    return std::sqrt(sum / static_cast<float>(count));
+}
+
+} // namespace Visualizer