Version 3.0

STK/LipFilt.cpp

@@ -0,0 +1,67 @@
+/**********************************************/
+/*  Lip Filter Object by Perry R. Cook, 1995-96*/    
+/*  The lip of the brass player has dynamics  */
+/*  which are controlled by the mass, spring  */
+/*  constant, and damping of the lip.  This   */
+/*  filter simulates that behavior and the    */
+/*  transmission/reflection properties as     */
+/*  well.  See Cook TBone and HosePlayer      */
+/*  instruments and articles.                 */
+/**********************************************/
+
+#include "LipFilt.h"
+
+LipFilt :: LipFilt()
+{
+    MY_FLOAT coeffs[2];
+    filter = new BiQuad;
+    coeffs[0] = (MY_FLOAT) 0.0;
+    coeffs[1] = (MY_FLOAT) 0.0;
+    filter->setZeroCoeffs(coeffs);
+    this->clear();
+}
+
+LipFilt :: ~LipFilt()
+{
+    delete filter;
+}
+
+void LipFilt :: clear()
+{
+    filter->clear();
+    lastOutput = (MY_FLOAT) 0.0;
+}
+
+void LipFilt :: setFreq(MY_FLOAT frequency)
+{
+    MY_FLOAT coeffs[2];
+    coeffs[0] = (MY_FLOAT) 2.0 * (MY_FLOAT) 0.997 * 
+		(MY_FLOAT)  cos(TWO_PI * frequency / SRATE);      /* damping should change with  */
+    coeffs[1] = (MY_FLOAT) (-0.997 * 0.997);  /* lip parameters, but not yet.*/
+    filter->setPoleCoeffs(coeffs);                             
+    filter->setGain((MY_FLOAT) 0.03);
+}
+
+/*  NOTE:  Here we should add lip tension                 */
+/*              settings based on Mass/Spring/Damping     */
+/*              Maybe in TookKit97                        */
+
+MY_FLOAT LipFilt :: tick(MY_FLOAT mouthSample,MY_FLOAT boreSample)    
+		/*   Perform "Table Lookup" By Polynomial Calculation */
+{
+    MY_FLOAT temp;
+    temp = mouthSample - boreSample;          /* Differential pressure              */
+    temp = filter->tick(temp);                /* Force -> position                  */
+    temp = temp*temp;                         /* Simple position to area mapping    */
+    if (temp > 1.0) temp = (MY_FLOAT) 1.0;    /* Saturation at + 1.0                */
+    lastOutput = temp * mouthSample;          /* Assume mouth input = area          */
+    lastOutput += ((MY_FLOAT) 1.0 - temp) 
+							  * boreSample;  /* and Bore reflection is compliment. */
+    return lastOutput;
+}
+
+MY_FLOAT LipFilt :: lastOut()
+{
+    return lastOutput;
+}
+