WIP: waveform visualization

Source/Waveform.cs

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+using Godot;
+using System;
+
+namespace AudioEditor;
+
+public partial class Waveform : Control
+{
+    private WaveformInfo _waveform;
+
+    public void SetWaveformInfo(WaveformInfo waveform)
+    {
+        _waveform = waveform;
+        QueueRedraw();
+    }
+
+    public override void _Draw()
+    {
+        if (_waveform == null) return;
+        base._Draw();
+
+        int width = (int)Size.X;
+        int height = (int)Size.Y;
+
+        // Downsample the waveform to get a reasonable number of peaks to draw
+        float[] averagePeaks = DownsampleToAveragePeaks(_waveform.Samples, width, _waveform.SampleRate);
+
+        // Begin drawing the waveform
+        for (int i = 0; i < width; i++)
+        {
+            float averagePeak = averagePeaks[i];
+
+            // Normalize the average peak to fit within the height of the control
+            int y = (int)(averagePeak * height / 2);
+
+            // Drawing the line in the positive and negative direction from the center
+            DrawLine(new Vector2(i, height / 2 - y), new Vector2(i, height / 2 + y), new Color(1, 1, 1, 0.7f));  // White with transparency
+        }
+    }
+
+    private float[] DownsampleToAveragePeaks(float[] samples, int targetWidth, int sampleRate)
+    {
+        int totalSamples = samples.Length;
+        float durationInSeconds = totalSamples / (float)sampleRate;  // Calculate the total duration in seconds
+        int stepSize = totalSamples / targetWidth;  // Larger chunks for downsampling
+
+        // If stepSize is 0 (due to rounding), default to 1 to prevent division by zero
+        if (stepSize == 0) stepSize = 1;
+
+        float[] averagePeaks = new float[targetWidth];
+
+        for (int i = 0; i < targetWidth; i++)
+        {
+            int startIndex = i * stepSize;
+            int endIndex = Math.Min(startIndex + stepSize, totalSamples);
+
+            // Calculate the average or peak for this window (you can use GetPeak if needed)
+            averagePeaks[i] = GetAverage(samples, startIndex, endIndex);
+        }
+
+        return averagePeaks;
+    }
+
+    // Get the average value of samples in the current window
+    private float GetAverage(float[] samples, int startIndex, int endIndex)
+    {
+        float sum = 0f;
+        int count = 0;
+        for (int i = startIndex; i < endIndex; i++)
+        {
+            sum += Math.Abs(samples[i]);  // Use absolute values for consistency
+            count++;
+        }
+        return count > 0 ? sum / count : 0f;
+    }
+
+    // Optional: You could use this method if you prefer showing the peak values
+    private float GetPeak(float[] samples, int startIndex, int endIndex)
+    {
+        float maxPeak = 0f;
+        for (int i = startIndex; i < endIndex; i++)
+        {
+            maxPeak = Math.Max(maxPeak, Math.Abs(samples[i]));
+        }
+        return maxPeak;
+    }
+
+    // This can be an alternative to GetAverage if you want to show average peak
+    private float GetAveragePeak(float[] samples, int startIndex, int endIndex)
+    {
+        float sum = 0f;
+        int count = 0;
+
+        for (int i = startIndex; i < endIndex; i++)
+        {
+            sum += Math.Abs(samples[i]);  // Use absolute value for a more stable peak
+            count++;
+        }
+
+        return count > 0 ? sum / count : 0f;  // Return the average
+    }
+}