refactor(mq_editor): store only squared amplitude after FFT, drop re/im

handoff(Claude): removed full spectrum storage from STFTCache frames;
getFFT() deleted; viewers use squaredAmplitude + 10*log10 directly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 6 insertions, 13 deletions

diff --git a/tools/mq_editor/fft.js b/tools/mq_editor/fft.js
index 36b9936..9b9bc94 100644
--- a/tools/mq_editor/fft.js
+++ b/tools/mq_editor/fft.js
@@ -109,7 +109,7 @@ class STFTCache {
     this.sampleRate = sampleRate;
     this.fftSize = fftSize;
     this.hopSize = hopSize;
-    this.frames = []; // Array of {time, offset, spectrum}
+    this.frames = []; // Array of {time, offset, squaredAmplitude}
     this.compute();
   }
 
@@ -131,18 +131,16 @@ class STFTCache {
         windowed[i] = frame[i] * w;
       }
 
-      // Compute FFT
-      const spectrum = realFFT(windowed);
-
-      // Cache squared amplitudes (re*re + im*im, no sqrt)
+      // Compute FFT, store only squared amplitudes (re*re + im*im, no sqrt)
+      const fftOut = realFFT(windowed);
       const squaredAmplitude = new Float32Array(this.fftSize / 2);
       for (let i = 0; i < this.fftSize / 2; ++i) {
-        const re = spectrum[i * 2];
-        const im = spectrum[i * 2 + 1];
+        const re = fftOut[i * 2];
+        const im = fftOut[i * 2 + 1];
         squaredAmplitude[i] = re * re + im * im;
       }
 
-      this.frames.push({time, offset, spectrum, squaredAmplitude});
+      this.frames.push({time, offset, squaredAmplitude});
     }
   }
 
@@ -175,11 +173,6 @@ class STFTCache {
     return this.getFrameAtIndex(frameIdx);
   }
 
-  getFFT(t) {
-    const frame = this.getFrameAtTime(t);
-    return frame ? frame.spectrum : null;
-  }
-
   getSquaredAmplitude(t) {
     const frame = this.getFrameAtTime(t);
     return frame ? frame.squaredAmplitude : null;