Implement IIRFilter node for WebAudio.

third_party/WebKit/Source/modules/webaudio/IIRProcessor.h

Index: third_party/WebKit/Source/modules/webaudio/IIRProcessor.h
diff --git a/third_party/WebKit/Source/modules/webaudio/IIRProcessor.h b/third_party/WebKit/Source/modules/webaudio/IIRProcessor.h
new file mode 100644
index 0000000000000000000000000000000000000000..5ea5d035a97b770a11a376a18631573cdb65a77e
--- /dev/null
+++ b/third_party/WebKit/Source/modules/webaudio/IIRProcessor.h
@@ -0,0 +1,43 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.

[tkent, 2016/01/13 03:28:28]

2016

[Raymond Toy, 2016/01/13 18:30:54]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IIRProcessor_h
+#define IIRProcessor_h
+
+#include "modules/webaudio/AudioNode.h"
+#include "platform/audio/AudioDSPKernel.h"
+#include "platform/audio/AudioDSPKernelProcessor.h"
+#include "platform/audio/IIRFilter.h"
+
+namespace blink {
+
+class IIRDSPKernel;
+
+class IIRProcessor final : public AudioDSPKernelProcessor {
+public:
+    IIRProcessor(float sampleRate, size_t numberOfChannels,
+        const Vector<double>& feedforwardCoef, const Vector<double>& feedbackCoef);
+    ~IIRProcessor() override;
+
+    PassOwnPtr<AudioDSPKernel> createKernel() override;
+
+    void process(const AudioBus* source, AudioBus* destination, size_t framesToProcess) override;
+
+    // Get the magnitude and phase response of the filter at the given
+    // set of frequencies (in Hz). The phase response is in radians.
+    void getFrequencyResponse(int nFrequencies, const float* frequencyHz, float* magResponse, float* phaseResponse);
+
+    AudioDoubleArray* feedback() { return &m_feedback; }
+    AudioDoubleArray* feedforward() { return &m_feedforward; }
+private:

[tkent, 2016/01/13 03:28:28]

nit: Add a blank line before |private:|.

[Raymond Toy, 2016/01/13 18:30:53]

Done.

+    // The feedback and feedforward filter coefficients for the IIR filter.
+    AudioDoubleArray m_feedback;
+    AudioDoubleArray m_feedforward;
+    // This holds the IIR kernel for computing the frequency response.
+    OwnPtr<IIRDSPKernel> m_responseKernel;
+};
+
+} // blink

[tkent, 2016/01/13 03:28:28]

nit: blink -> namespace blink

[Raymond Toy, 2016/01/13 18:30:53]

Done.

+
+#endif // IIRProcessor_h