Add methods to compute magnitude and phase response for biquads
[WebKit-https.git] / Source / WebCore / webaudio / BiquadFilterNode.cpp
1 /*
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24
25 #include "config.h"
26
27 #if ENABLE(WEB_AUDIO)
28
29 #include "BiquadFilterNode.h"
30
31 #include "ExceptionCode.h"
32
33 namespace WebCore {
34
35 BiquadFilterNode::BiquadFilterNode(AudioContext* context, float sampleRate)
36     : AudioBasicProcessorNode(context, sampleRate)
37 {
38     // Initially setup as lowpass filter.
39     m_processor = adoptPtr(new BiquadProcessor(BiquadProcessor::LowPass, sampleRate, 1, false));
40     biquadProcessor()->parameter1()->setContext(context);
41     biquadProcessor()->parameter2()->setContext(context);
42     biquadProcessor()->parameter3()->setContext(context);
43     setNodeType(NodeTypeBiquadFilter);
44 }
45
46 void BiquadFilterNode::setType(unsigned short type, ExceptionCode& ec)
47 {
48     if (type > BiquadProcessor::Allpass) {
49         ec = NOT_SUPPORTED_ERR;
50         return;
51     }
52     
53     biquadProcessor()->setType(static_cast<BiquadProcessor::FilterType>(type));
54 }
55
56
57 void BiquadFilterNode::getFrequencyResponse(const Float32Array* frequencyHz,
58                                             Float32Array* magResponse,
59                                             Float32Array* phaseResponse)
60 {
61     if (!frequencyHz || !magResponse || !phaseResponse)
62         return;
63     
64     int n = std::min(frequencyHz->length(),
65                      std::min(magResponse->length(), phaseResponse->length()));
66
67     if (n) {
68         biquadProcessor()->getFrequencyResponse(n,
69                                                 frequencyHz->data(),
70                                                 magResponse->data(),
71                                                 phaseResponse->data());
72     }
73 }
74
75 } // namespace WebCore
76
77 #endif // ENABLE(WEB_AUDIO)