chris@164: /*
chris@164:  *
chris@164:  * Plectrum model for touching and plucking strings
chris@164:  *
chris@164:  * Christian Heinrichs 04/2015
chris@164:  *
chris@164:  * [inspired by E. Berdahl's pluck~ abstraction for the FireFader]
chris@164:  *
chris@164:  */
chris@164: 
chris@164: #include "Plectrum.h"
chris@164: 
chris@164: #include "../include/Utilities.h"
chris@164: #include <cmath>
chris@164: #include <stdio.h>
chris@164: #include <cstdlib>
chris@164: 
chris@164: Plectrum::Plectrum()	{
chris@164: 
chris@164: 	_contact = 0;
chris@164: 	_lastDistance = 0;
chris@164: 
chris@164: }
chris@164: 
chris@164: void Plectrum::setup(float spring, float damp, float hyst)	{
chris@164: 
chris@164: 	_spring = spring;
chris@164: 	_damp = damp;
chris@164: 	_hyst = hyst;
chris@164: 
chris@164: }
chris@164: 
chris@164: float Plectrum::update(float position, float stringPosition)	{
chris@164: 
chris@164: 	float distance = position - stringPosition;
chris@164: 
chris@164: 	// Calculate spring/damp forces based on distance to string
chris@164: 
chris@164: 	float springOut = distance * _spring;
chris@164: 
chris@164: 	float dampOut = (distance - _lastDistance) * 44100;
chris@164: 
chris@164: 	float out = springOut+dampOut;
chris@164: 
chris@164: 	// If distance crosses zero, enable contact
chris@164: 
chris@164: 	if((distance>0 && _lastDistance<=0)||(distance<0 && _lastDistance>=0))
chris@164: 		_contact = 1;
chris@164: 
chris@164: 	// If distance exceeds hysteresis threshold, jump to zero (i.e. 'pluck')
chris@164: 
chris@164: 	if(fabs(distance)>_hyst)
chris@164: 		_contact = 0;
chris@164: 
chris@164: 	// FIXME: contact doesn't switch back to zero if distance goes back in original direction
chris@164: 
chris@164: 	_lastDistance = distance;
chris@164: 
chris@164: 	return out * _contact;
chris@164: 
chris@164: }