/*
 * Filename:    Envelope.cpp
 *
 * Description:
 *
 *
 * Version:     
 * Created:     Sun Mar  8 08:41:17 2020
 * Revision:    None
 * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
 *
 */


#include "Envelope.h"
namespace amalgam {
namespace FM {
    float Envelope::process () {
	switch (envstate) {
	case _e_off:
	    if (*gate) {
		t = 0;
		envstate = _e_attack;
		return process();
	    }
	    break;
	case _e_attack:
	    if (*gate) {
		if ( t < attack ) {
		    float stepsize = (max_level - min_level) / attack;
		    t++;
		    return t * stepsize;
		} else {
		    t = 0;
		    envstate = _e_decay;
		    return max_level; 
		}
	    } else {
		envstate = _e_attackrelease;
		return process();
	    }
	    break;
	case _e_decay:
	    if (*gate) {
		if (t < decay) {
		    float stepsize = (max_level - sustain_level) / decay;
		    t++;
		    return (max_level - (t * stepsize));
		    
		} else {
		    envstate = _e_sustain;
		    return sustain_level;
		}
	    } else {
		envstate = _e_attackrelease;
		return process();
	    }
	    break;
	case _e_sustain:
	    if (!sustain) {
		envstate = _e_release;
		t = 0;
		return process();
	    }
	    if (!*gate) {
		t = 0;
		envstate = _e_release;
		return sustain_level;
	    }
	    return sustain_level;
	    break;
	case _e_release:
	    if (*gate) {
		// reset envelope.
		envstate=_e_off;
		return process();
	    }
	    if (modMode) {
		return sustain_level;
	    }
	    if (t < release) {
		float stepsize = (sustain_level - min_level) / release;
		t++;
		return sustain_level - (stepsize * t);
	    } else {
		envstate = _e_off;
		return min_level;
	    }
	    
	    break;
	case _e_attackrelease:
	    if (*gate) {
		//reset envelope
		envstate=_e_off;
		return process();
	    }
	    return 0.0f;
	    break;
	    
	}
	return 0.0f; // if this is reached, something went wrong or an unhandled function was used.
    }
}
}