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      1 /*
      2  * Copyright (C) 2011, Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1.  Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2.  Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
     20  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     23  */
     24 
     25 #ifndef BiquadFilterNode_h
     26 #define BiquadFilterNode_h
     27 
     28 #include "modules/webaudio/AudioBasicProcessorNode.h"
     29 #include "modules/webaudio/BiquadProcessor.h"
     30 
     31 namespace WebCore {
     32 
     33 class AudioParam;
     34 
     35 class BiquadFilterNode : public AudioBasicProcessorNode {
     36 public:
     37     // These must be defined as in the .idl file and must match those in the BiquadProcessor class.
     38     enum {
     39         LOWPASS = 0,
     40         HIGHPASS = 1,
     41         BANDPASS = 2,
     42         LOWSHELF = 3,
     43         HIGHSHELF = 4,
     44         PEAKING = 5,
     45         NOTCH = 6,
     46         ALLPASS = 7
     47     };
     48 
     49     static PassRefPtr<BiquadFilterNode> create(AudioContext* context, float sampleRate)
     50     {
     51         return adoptRef(new BiquadFilterNode(context, sampleRate));
     52     }
     53 
     54     String type() const;
     55     bool setType(unsigned); // Returns true on success.
     56     void setType(const String&);
     57 
     58     AudioParam* frequency() { return biquadProcessor()->parameter1(); }
     59     AudioParam* q() { return biquadProcessor()->parameter2(); }
     60     AudioParam* gain() { return biquadProcessor()->parameter3(); }
     61     AudioParam* detune() { return biquadProcessor()->parameter4(); }
     62 
     63     // Get the magnitude and phase response of the filter at the given
     64     // set of frequencies (in Hz). The phase response is in radians.
     65     void getFrequencyResponse(const Float32Array* frequencyHz,
     66                               Float32Array* magResponse,
     67                               Float32Array* phaseResponse);
     68 
     69 private:
     70     BiquadFilterNode(AudioContext*, float sampleRate);
     71 
     72     BiquadProcessor* biquadProcessor() { return static_cast<BiquadProcessor*>(processor()); }
     73 };
     74 
     75 } // namespace WebCore
     76 
     77 #endif // BiquadFilterNode_h
     78