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<h1>BiQuad.h</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="preprocessor">#ifndef STK_BIQUAD_H</span>
<a name="l00002"></a>00002 <span class="preprocessor"></span><span class="preprocessor">#define STK_BIQUAD_H</span>
<a name="l00003"></a>00003 <span class="preprocessor"></span>
<a name="l00004"></a>00004 <span class="preprocessor">#include &quot;Filter.h&quot;</span>
<a name="l00005"></a>00005
<a name="l00006"></a>00006 <span class="keyword">namespace </span>stk {
<a name="l00007"></a>00007
<a name="l00008"></a>00008 <span class="comment">/***************************************************/</span>
<a name="l00018"></a>00018 <span class="comment">/***************************************************/</span>
<a name="l00019"></a>00019
<a name="l00020"></a><a class="code" href="classstk_1_1BiQuad.html">00020</a> <span class="keyword">class </span><a class="code" href="classstk_1_1BiQuad.html" title="STK biquad (two-pole, two-zero) filter class.">BiQuad</a> : <span class="keyword">public</span> <a class="code" href="classstk_1_1Filter.html" title="STK abstract filter class.">Filter</a>
<a name="l00021"></a>00021 {
<a name="l00022"></a>00022 <span class="keyword">public</span>:
<a name="l00023"></a>00023
<a name="l00025"></a>00025 <a class="code" href="classstk_1_1BiQuad.html#a91aab9d1b4833e156edcf59cbe276e3f" title="Default constructor creates a second-order pass-through filter.">BiQuad</a>();
<a name="l00026"></a>00026
<a name="l00028"></a>00028 <a class="code" href="classstk_1_1BiQuad.html#ad7e81be1c4e5c5ab69474f6df2610984" title="Class destructor.">~BiQuad</a>();
<a name="l00029"></a>00029
<a name="l00031"></a><a class="code" href="classstk_1_1BiQuad.html#aab468cd1aa79b95442b15bb04d8bb211">00031</a> <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#aab468cd1aa79b95442b15bb04d8bb211" title="A function to enable/disable the automatic updating of class data when the STK sample...">ignoreSampleRateChange</a>( <span class="keywordtype">bool</span> ignore = <span class="keyword">true</span> ) { ignoreSampleRateChange_ = ignore; };
<a name="l00032"></a>00032
<a name="l00034"></a>00034 <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#aeed58196cf798f664cddbb9a8564c7b5" title="Set all filter coefficients.">setCoefficients</a>( StkFloat b0, StkFloat b1, StkFloat b2, StkFloat a1, StkFloat a2, <span class="keywordtype">bool</span> clearState = <span class="keyword">false</span> );
<a name="l00035"></a>00035
<a name="l00037"></a><a class="code" href="classstk_1_1BiQuad.html#a26ee25d08116b20f326001166f087853">00037</a> <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#a26ee25d08116b20f326001166f087853" title="Set the b[0] coefficient value.">setB0</a>( StkFloat b0 ) { b_[0] = b0; };
<a name="l00038"></a>00038
<a name="l00040"></a><a class="code" href="classstk_1_1BiQuad.html#add364ed410b3ed2a2b29b8a5fea127c8">00040</a> <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#add364ed410b3ed2a2b29b8a5fea127c8" title="Set the b[1] coefficient value.">setB1</a>( StkFloat b1 ) { b_[1] = b1; };
<a name="l00041"></a>00041
<a name="l00043"></a><a class="code" href="classstk_1_1BiQuad.html#a208a654dd3393ed0b2b86ad56d9cf3e1">00043</a> <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#a208a654dd3393ed0b2b86ad56d9cf3e1" title="Set the b[2] coefficient value.">setB2</a>( StkFloat b2 ) { b_[2] = b2; };
<a name="l00044"></a>00044
<a name="l00046"></a><a class="code" href="classstk_1_1BiQuad.html#a1c9799e47163fe8a59fd85196c089cb3">00046</a> <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#a1c9799e47163fe8a59fd85196c089cb3" title="Set the a[1] coefficient value.">setA1</a>( StkFloat a1 ) { a_[1] = a1; };
<a name="l00047"></a>00047
<a name="l00049"></a><a class="code" href="classstk_1_1BiQuad.html#ae28afd560df11435ea54f128d23b9383">00049</a> <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#ae28afd560df11435ea54f128d23b9383" title="Set the a[2] coefficient value.">setA2</a>( StkFloat a2 ) { a_[2] = a2; };
<a name="l00050"></a>00050
<a name="l00052"></a>00052
<a name="l00063"></a>00063 <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#a55aaa01fd4156f1fac1168f526e3d969" title="Sets the filter coefficients for a resonance at frequency (in Hz).">setResonance</a>( StkFloat frequency, StkFloat radius, <span class="keywordtype">bool</span> normalize = <span class="keyword">false</span> );
<a name="l00064"></a>00064
<a name="l00066"></a>00066
<a name="l00072"></a>00072 <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#ae10a26fc319ba357bc92df4e528c2d8f" title="Set the filter coefficients for a notch at frequency (in Hz).">setNotch</a>( StkFloat frequency, StkFloat radius );
<a name="l00073"></a>00073
<a name="l00075"></a>00075
<a name="l00081"></a>00081 <span class="keywordtype">void</span> <a class="code" href="classstk_1_1BiQuad.html#a28881f5876ce5bdcc846367cca9363f7" title="Sets the filter zeroes for equal resonance gain.">setEqualGainZeroes</a>( <span class="keywordtype">void</span> );
<a name="l00082"></a>00082
<a name="l00084"></a><a class="code" href="classstk_1_1BiQuad.html#a412f224363b1a222423ecf0cd7be9063">00084</a> StkFloat <a class="code" href="classstk_1_1BiQuad.html#a412f224363b1a222423ecf0cd7be9063" title="Return the last computed output value.">lastOut</a>( <span class="keywordtype">void</span> )<span class="keyword"> const </span>{ <span class="keywordflow">return</span> lastFrame_[0]; };
<a name="l00085"></a>00085
<a name="l00087"></a>00087 StkFloat <a class="code" href="classstk_1_1BiQuad.html#a648086962c3cddcaa09c46a002c3e635" title="Input one sample to the filter and return a reference to one output.">tick</a>( StkFloat input );
<a name="l00088"></a>00088
<a name="l00090"></a>00090
<a name="l00098"></a>00098 <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; <a class="code" href="classstk_1_1BiQuad.html#a648086962c3cddcaa09c46a002c3e635" title="Input one sample to the filter and return a reference to one output.">tick</a>( <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; frames, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> channel = 0 );
<a name="l00099"></a>00099
<a name="l00101"></a>00101
<a name="l00109"></a>00109 <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; <a class="code" href="classstk_1_1BiQuad.html#a648086962c3cddcaa09c46a002c3e635" title="Input one sample to the filter and return a reference to one output.">tick</a>( <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; iFrames, <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a> &amp;oFrames, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> iChannel = 0, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> oChannel = 0 );
<a name="l00110"></a>00110
<a name="l00111"></a>00111 <span class="keyword">protected</span>:
<a name="l00112"></a>00112
<a name="l00113"></a>00113 <span class="keyword">virtual</span> <span class="keywordtype">void</span> sampleRateChanged( StkFloat newRate, StkFloat oldRate );
<a name="l00114"></a>00114 };
<a name="l00115"></a>00115
<a name="l00116"></a><a class="code" href="classstk_1_1BiQuad.html#a648086962c3cddcaa09c46a002c3e635">00116</a> <span class="keyword">inline</span> StkFloat <a class="code" href="classstk_1_1BiQuad.html#a648086962c3cddcaa09c46a002c3e635" title="Input one sample to the filter and return a reference to one output.">BiQuad :: tick</a>( StkFloat input )
<a name="l00117"></a>00117 {
<a name="l00118"></a>00118 inputs_[0] = gain_ * input;
<a name="l00119"></a>00119 lastFrame_[0] = b_[0] * inputs_[0] + b_[1] * inputs_[1] + b_[2] * inputs_[2];
<a name="l00120"></a>00120 lastFrame_[0] -= a_[2] * outputs_[2] + a_[1] * outputs_[1];
<a name="l00121"></a>00121 inputs_[2] = inputs_[1];
<a name="l00122"></a>00122 inputs_[1] = inputs_[0];
<a name="l00123"></a>00123 outputs_[2] = outputs_[1];
<a name="l00124"></a>00124 outputs_[1] = lastFrame_[0];
<a name="l00125"></a>00125
<a name="l00126"></a>00126 <span class="keywordflow">return</span> lastFrame_[0];
<a name="l00127"></a>00127 }
<a name="l00128"></a>00128
<a name="l00129"></a><a class="code" href="classstk_1_1BiQuad.html#af903e41217838470a5f267a20b905a12">00129</a> <span class="keyword">inline</span> <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; <a class="code" href="classstk_1_1BiQuad.html#a648086962c3cddcaa09c46a002c3e635" title="Input one sample to the filter and return a reference to one output.">BiQuad :: tick</a>( <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; frames, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> channel )
<a name="l00130"></a>00130 {
<a name="l00131"></a>00131 <span class="preprocessor">#if defined(_STK_DEBUG_)</span>
<a name="l00132"></a>00132 <span class="preprocessor"></span> <span class="keywordflow">if</span> ( channel &gt;= frames.<a class="code" href="classstk_1_1StkFrames.html#aec7ef9c46675a24111aa6e2fda3ba870" title="Return the number of channels represented by the data.">channels</a>() ) {
<a name="l00133"></a>00133 errorString_ &lt;&lt; <span class="stringliteral">&quot;BiQuad::tick(): channel and StkFrames arguments are incompatible!&quot;</span>;
<a name="l00134"></a>00134 <a class="code" href="classstk_1_1Stk.html#a48ac73a0d8ca28445ba1a054e1f061ff" title="Static function for error reporting and handling using c-strings.">handleError</a>( StkError::FUNCTION_ARGUMENT );
<a name="l00135"></a>00135 }
<a name="l00136"></a>00136 <span class="preprocessor">#endif</span>
<a name="l00137"></a>00137 <span class="preprocessor"></span>
<a name="l00138"></a>00138 StkFloat *samples = &amp;frames[channel];
<a name="l00139"></a>00139 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> hop = frames.<a class="code" href="classstk_1_1StkFrames.html#aec7ef9c46675a24111aa6e2fda3ba870" title="Return the number of channels represented by the data.">channels</a>();
<a name="l00140"></a>00140 <span class="keywordflow">for</span> ( <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> i=0; i&lt;frames.<a class="code" href="classstk_1_1StkFrames.html#a05b1ab6fa750a8221a7d65c30e0cdab9" title="Return the number of sample frames represented by the data.">frames</a>(); i++, samples += hop ) {
<a name="l00141"></a>00141 inputs_[0] = gain_ * *samples;
<a name="l00142"></a>00142 *samples = b_[0] * inputs_[0] + b_[1] * inputs_[1] + b_[2] * inputs_[2];
<a name="l00143"></a>00143 *samples -= a_[2] * outputs_[2] + a_[1] * outputs_[1];
<a name="l00144"></a>00144 inputs_[2] = inputs_[1];
<a name="l00145"></a>00145 inputs_[1] = inputs_[0];
<a name="l00146"></a>00146 outputs_[2] = outputs_[1];
<a name="l00147"></a>00147 outputs_[1] = *samples;
<a name="l00148"></a>00148 }
<a name="l00149"></a>00149
<a name="l00150"></a>00150 lastFrame_[0] = outputs_[1];
<a name="l00151"></a>00151 <span class="keywordflow">return</span> frames;
<a name="l00152"></a>00152 }
<a name="l00153"></a>00153
<a name="l00154"></a><a class="code" href="classstk_1_1BiQuad.html#ac9836f0e074ea9516727f27eb9b411aa">00154</a> <span class="keyword">inline</span> <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; <a class="code" href="classstk_1_1BiQuad.html#a648086962c3cddcaa09c46a002c3e635" title="Input one sample to the filter and return a reference to one output.">BiQuad :: tick</a>( <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; iFrames, <a class="code" href="classstk_1_1StkFrames.html" title="An STK class to handle vectorized audio data.">StkFrames</a>&amp; oFrames, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> iChannel, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> oChannel )
<a name="l00155"></a>00155 {
<a name="l00156"></a>00156 <span class="preprocessor">#if defined(_STK_DEBUG_)</span>
<a name="l00157"></a>00157 <span class="preprocessor"></span> <span class="keywordflow">if</span> ( iChannel &gt;= iFrames.<a class="code" href="classstk_1_1StkFrames.html#aec7ef9c46675a24111aa6e2fda3ba870" title="Return the number of channels represented by the data.">channels</a>() || oChannel &gt;= oFrames.<a class="code" href="classstk_1_1StkFrames.html#aec7ef9c46675a24111aa6e2fda3ba870" title="Return the number of channels represented by the data.">channels</a>() ) {
<a name="l00158"></a>00158 errorString_ &lt;&lt; <span class="stringliteral">&quot;BiQuad::tick(): channel and StkFrames arguments are incompatible!&quot;</span>;
<a name="l00159"></a>00159 <a class="code" href="classstk_1_1Stk.html#a48ac73a0d8ca28445ba1a054e1f061ff" title="Static function for error reporting and handling using c-strings.">handleError</a>( StkError::FUNCTION_ARGUMENT );
<a name="l00160"></a>00160 }
<a name="l00161"></a>00161 <span class="preprocessor">#endif</span>
<a name="l00162"></a>00162 <span class="preprocessor"></span>
<a name="l00163"></a>00163 StkFloat *iSamples = &amp;iFrames[iChannel];
<a name="l00164"></a>00164 StkFloat *oSamples = &amp;oFrames[oChannel];
<a name="l00165"></a>00165 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> iHop = iFrames.<a class="code" href="classstk_1_1StkFrames.html#aec7ef9c46675a24111aa6e2fda3ba870" title="Return the number of channels represented by the data.">channels</a>(), oHop = oFrames.<a class="code" href="classstk_1_1StkFrames.html#aec7ef9c46675a24111aa6e2fda3ba870" title="Return the number of channels represented by the data.">channels</a>();
<a name="l00166"></a>00166 <span class="keywordflow">for</span> ( <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> i=0; i&lt;iFrames.<a class="code" href="classstk_1_1StkFrames.html#a05b1ab6fa750a8221a7d65c30e0cdab9" title="Return the number of sample frames represented by the data.">frames</a>(); i++, iSamples += iHop, oSamples += oHop ) {
<a name="l00167"></a>00167 inputs_[0] = gain_ * *iSamples;
<a name="l00168"></a>00168 *oSamples = b_[0] * inputs_[0] + b_[1] * inputs_[1] + b_[2] * inputs_[2];
<a name="l00169"></a>00169 *oSamples -= a_[2] * outputs_[2] + a_[1] * outputs_[1];
<a name="l00170"></a>00170 inputs_[2] = inputs_[1];
<a name="l00171"></a>00171 inputs_[1] = inputs_[0];
<a name="l00172"></a>00172 outputs_[2] = outputs_[1];
<a name="l00173"></a>00173 outputs_[1] = *oSamples;
<a name="l00174"></a>00174 }
<a name="l00175"></a>00175
<a name="l00176"></a>00176 lastFrame_[0] = outputs_[1];
<a name="l00177"></a>00177 <span class="keywordflow">return</span> iFrames;
<a name="l00178"></a>00178 }
<a name="l00179"></a>00179
<a name="l00180"></a>00180 } <span class="comment">// stk namespace</span>
<a name="l00181"></a>00181
<a name="l00182"></a>00182 <span class="preprocessor">#endif</span>
<a name="l00183"></a>00183 <span class="preprocessor"></span>
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