switch.cpp

/***************************************************************************
 *   Copyright (C) 2005 by David Saxton                                    *
 *   david@bluehaze.org                                                    *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

#include "circuitdocument.h"
#include "component.h"
#include "ecnode.h"
#include "pin.h"
#include "resistance.h"
#include "simulator.h"
#include "switch.h"

#include <kdebug.h>
#include <qtimer.h>

#include <cmath>
#include <stdlib.h> // for rand
#include <time.h>

Switch::Switch( Component * parent, Pin * p1, Pin * p2, State state )
{
        m_bouncePeriod_ms = 5;
        m_bBounce = false;
        m_bounceStart = 0;
        m_pBounceResistance = 0;
        m_pP1 = p1;
        m_pP2 = p2;
        m_pComponent = parent;
        m_pStopBouncingTimer = new QTimer( this );
        connect( m_pStopBouncingTimer, SIGNAL(timeout()), this, SLOT(stopBouncing()) );
        
        // Force update
        m_state = (state == Open) ? Closed : Open;
        setState(state);
}


Switch::~ Switch( )
{
        if (m_pP1)
                m_pP1->setSwitchConnected( m_pP2, false );
        
        if (m_pP2)
                m_pP2->setSwitchConnected( m_pP1, false );
}


void Switch::setState( State state )
{
        if ( m_state == state )
                return;
        
        m_state = state;
        
        if ( m_bBounce )
                startBouncing();
        else
        {
                // I'm being lazy...calling stopBouncing will connect the stuff
                stopBouncing();
        }
}


void Switch::setBounce( bool bounce, int msec )
{
        m_bBounce = bounce;
        m_bouncePeriod_ms = msec;
}


void Switch::startBouncing()
{
        if ( m_pBounceResistance )
        {
                // Already active?
                return;
        }
        
        CircuitDocument * cd = m_pComponent->circuitDocument();
        if ( !cd )
                return;
        
//      kdDebug() << k_funcinfo << endl;
        
        m_pBounceResistance = m_pComponent->createResistance( m_pP1, m_pP2, 10000 );
        m_bounceStart = Simulator::self()->time();
        Simulator::self()->attachSwitch(this);
//      kdDebug() << "m_bounceStart="<<m_bounceStart<<" m_bouncePeriod_ms="<<m_bouncePeriod_ms<<endl;
        
        // initialize random generator
        srand ( time(NULL) );
        
        // Give our bounce resistor an initial value
        bounce();
}


void Switch::bounce()
{
        int bounced_ms = (( Simulator::self()->time() - m_bounceStart ) * 1000) / LOGIC_UPDATE_RATE;
        if ( bounced_ms >= m_bouncePeriod_ms )
        {
                if ( !m_pStopBouncingTimer->isActive() )
                        m_pStopBouncingTimer->start( 0, true );
                return;
        }
        
        double g = double(rand())/double(RAND_MAX);
        
        // 4th power of the conductance seems to give a nice distribution
        g = g * g * g * g;
        
        m_pBounceResistance->setConductance( g );
}


void Switch::stopBouncing()
{
        Simulator::self()->detachSwitch(this );
        m_pComponent->removeElement( m_pBounceResistance, true );
        m_pBounceResistance = 0;
        
        bool connected = (m_state == Closed);
        
        if ( m_pP1 && m_pP2 )
        {
                m_pP1->setSwitchConnected( m_pP2, connected );
                m_pP2->setSwitchConnected( m_pP1, connected );
        }
        
        if ( CircuitDocument * cd = m_pComponent->circuitDocument() )
                cd->requestAssignCircuits();
}


bool Switch::calculateCurrent()
{
        if ( !m_pP1 || !m_pP2 )
                return false;
        
        if ( state() == Open )
        {
                m_pP1->setSwitchCurrentKnown( this );
                m_pP2->setSwitchCurrentKnown( this );
                return true;
        }
        
        Pin * pins[2] = { m_pP1, m_pP2 };
        
        double current = 0.0;
        bool currentKnown = false;
        
        int pol;
        for ( unsigned i = 0; i < 2; ++i )
        {
                pol = (i == 0) ? 1 : -1;
                
                const WireList inputs = pins[i]->inputWireList();
                const WireList outputs = pins[i]->outputWireList();
                
                currentKnown = true;
                current = 0.0;
                
                WireList::const_iterator end = inputs.end();
                for ( WireList::const_iterator it = inputs.begin(); it != end; ++it )
                {
                        if ( !(*it) )
                                continue;
                        
                        if ( !(*it)->currentIsKnown() )
                        {
                                currentKnown = false;
                                break;
                        }
                        
                        current += (*it)->current();
                }
                
                if ( !currentKnown )
                        continue;
                
                end = outputs.end();
                for ( WireList::const_iterator it = outputs.begin(); it != end; ++it )
                {
                        if ( !(*it) )
                                continue;
                        
                        if ( !(*it)->currentIsKnown() )
                        {
                                currentKnown = false;
                                break;
                        }
                        
                        current -= (*it)->current();
                }
                
                if ( currentKnown )
                        break;
        }
        
        if ( !currentKnown )
                return false;
        
        m_pP1->setSwitchCurrentKnown( this );
        m_pP2->setSwitchCurrentKnown( this );
        m_pP1->mergeCurrent( -current * pol );
        m_pP2->mergeCurrent( current * pol );
        
        return true;
}

#include "switch.moc"

---