Add constant twoPiDouble/twoPiFloat to MathExtras.h

Source/platform/audio/FFTFrame.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 133 matching lines @@
         double phase1 = arg(c1);
         double phase2 = arg(c2);
 
         double deltaPhase1 = phase1 - lastPhase1;
         double deltaPhase2 = phase2 - lastPhase2;
         lastPhase1 = phase1;
         lastPhase2 = phase2;
 
         // Unwrap phase deltas
         if (deltaPhase1 > piDouble)
-            deltaPhase1 -= 2.0 * piDouble;
+            deltaPhase1 -= twoPiDouble;
         if (deltaPhase1 < -piDouble)
-            deltaPhase1 += 2.0 * piDouble;
+            deltaPhase1 += twoPiDouble;
         if (deltaPhase2 > piDouble)
-            deltaPhase2 -= 2.0 * piDouble;
+            deltaPhase2 -= twoPiDouble;
         if (deltaPhase2 < -piDouble)
-            deltaPhase2 += 2.0 * piDouble;
+            deltaPhase2 += twoPiDouble;
 
         // Blend group-delays
         double deltaPhaseBlend;
 
         if (deltaPhase1 - deltaPhase2 > piDouble)
-            deltaPhaseBlend = s1 * deltaPhase1 + s2 * (2.0 * piDouble + deltaPhase2);
+            deltaPhaseBlend = s1 * deltaPhase1 + s2 * (twoPiDouble + deltaPhase2);
         else if (deltaPhase2 - deltaPhase1 > piDouble)
-            deltaPhaseBlend = s1 * (2.0 * piDouble + deltaPhase1) + s2 * deltaPhase2;
+            deltaPhaseBlend = s1 * (twoPiDouble + deltaPhase1) + s2 * deltaPhase2;
         else
             deltaPhaseBlend = s1 * deltaPhase1 + s2 * deltaPhase2;
 
         phaseAccum += deltaPhaseBlend;
 
         // Unwrap
         if (phaseAccum > piDouble)
-            phaseAccum -= 2.0 * piDouble;
+            phaseAccum -= twoPiDouble;
         if (phaseAccum < -piDouble)
-            phaseAccum += 2.0 * piDouble;
+            phaseAccum += twoPiDouble;
 
         Complex c = complexFromMagnitudePhase(mag, phaseAccum);
 
         realP[i] = static_cast<float>(c.real());
         imagP[i] = static_cast<float>(c.imag());
     }
 }
 
 double FFTFrame::extractAverageGroupDelay()
 {
     float* realP = realData();
     float* imagP = imagData();
 
     double aveSum = 0.0;
     double weightSum = 0.0;
     double lastPhase = 0.0;
 
     int halfSize = fftSize() / 2;
 
-    const double kSamplePhaseDelay = (2.0 * piDouble) / double(fftSize());
+    const double kSamplePhaseDelay = (twoPiDouble) / double(fftSize());
 
     // Calculate weighted average group delay
     for (int i = 0; i < halfSize; i++) {
         Complex c(realP[i], imagP[i]);
         double mag = abs(c);
         double phase = arg(c);
 
         double deltaPhase = phase - lastPhase;
         lastPhase = phase;
 
         // Unwrap
         if (deltaPhase < -piDouble)
-            deltaPhase += 2.0 * piDouble;
+            deltaPhase += twoPiDouble;
         if (deltaPhase > piDouble)
-            deltaPhase -= 2.0 * piDouble;
+            deltaPhase -= twoPiDouble;
 
         aveSum += mag * deltaPhase;
         weightSum += mag;
     }
 
     // Note how we invert the phase delta wrt frequency since this is how group delay is defined
     double ave = aveSum / weightSum;
     double aveSampleDelay = -ave / kSamplePhaseDelay;
 
     // Leave 20 sample headroom (for leading edge of impulse)
     if (aveSampleDelay > 20.0)
         aveSampleDelay -= 20.0;
 
     // Remove average group delay (minus 20 samples for headroom)
     addConstantGroupDelay(-aveSampleDelay);
 
     // Remove DC offset
     realP[0] = 0.0f;
 
     return aveSampleDelay;
 }
 
 void FFTFrame::addConstantGroupDelay(double sampleFrameDelay)
 {
     int halfSize = fftSize() / 2;
 
     float* realP = realData();
     float* imagP = imagData();
 
-    const double kSamplePhaseDelay = (2.0 * piDouble) / double(fftSize());
+    const double kSamplePhaseDelay = (twoPiDouble) / double(fftSize());
 
     double phaseAdj = -sampleFrameDelay * kSamplePhaseDelay;
 
     // Add constant group delay
     for (int i = 1; i < halfSize; i++) {
         Complex c(realP[i], imagP[i]);
         double mag = abs(c);
         double phase = arg(c);
 
         phase += i * phaseAdj;
@@ skipping 22 matching lines @@
 
         WTF_LOG(WebAudio, "[%d] (%f %f)\n", i, mag, phase);
     }
     WTF_LOG(WebAudio, "****\n");
 }
 #endif // NDEBUG
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)