Add support for WaveShaperNode.oversample

Source/modules/webaudio/WaveShaperProcessor.cpp

 /*
  * Copyright (C) 2011, 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 13 matching lines @@
 
 #include "config.h"
 
 #if ENABLE(WEB_AUDIO)
 
 #include "modules/webaudio/WaveShaperProcessor.h"
 
 #include "modules/webaudio/WaveShaperDSPKernel.h"
 
 namespace WebCore {
-    
+
 WaveShaperProcessor::WaveShaperProcessor(float sampleRate, size_t numberOfChannels)
     : AudioDSPKernelProcessor(sampleRate, numberOfChannels)
+    , m_oversample(OverSampleNone)
 {
 }
 
 WaveShaperProcessor::~WaveShaperProcessor()
 {
     if (isInitialized())
         uninitialize();
 }
 
 PassOwnPtr<AudioDSPKernel> WaveShaperProcessor::createKernel()
 {
     return adoptPtr(new WaveShaperDSPKernel(this));
 }
 
 void WaveShaperProcessor::setCurve(Float32Array* curve)
 {
     // This synchronizes with process().
     MutexLocker processLocker(m_processLock);
     
     m_curve = curve;
 }
 
+void WaveShaperProcessor::setOversample(OverSampleType oversample)
+{
+    // This synchronizes with process().
+    MutexLocker processLocker(m_processLock);
+
+    m_oversample = oversample;
+
+    if (oversample != OverSampleNone) {
+        for (unsigned i = 0; i < m_kernels.size(); ++i) {
+            WaveShaperDSPKernel* kernel = static_cast<WaveShaperDSPKernel*>(m_kernels[i].get());
+            kernel->lazyInitializeOversampling();
+        }
+    }
+}
+
 void WaveShaperProcessor::process(const AudioBus* source, AudioBus* destination, size_t framesToProcess)
 {
     if (!isInitialized()) {
         destination->zero();
         return;
     }
 
     bool channelCountMatches = source->numberOfChannels() == destination->numberOfChannels() && source->numberOfChannels() == m_kernels.size();
     ASSERT(channelCountMatches);
     if (!channelCountMatches)
         return;
 
     // The audio thread can't block on this lock, so we call tryLock() instead.
     MutexTryLocker tryLocker(m_processLock);
     if (tryLocker.locked()) {        
         // For each channel of our input, process using the corresponding WaveShaperDSPKernel into the output channel.
         for (unsigned i = 0; i < m_kernels.size(); ++i)
             m_kernels[i]->process(source->channel(i)->data(), destination->channel(i)->mutableData(), framesToProcess);
     } else {
         // Too bad - the tryLock() failed. We must be in the middle of a setCurve() call.
         destination->zero();
     }
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)