C++ TRACK::Back方法代码示例

TRACK* TRACK::GetBestInsertPoint( BOARD* aPcb )
{
    TRACK* track;

    // When reading from a file most of the items will already be in the correct order.
    // Searching from the back therefore takes us from n^2 to essentially 0.

    if( Type() == PCB_ZONE_T )  // Deprecated items, only found in very old boards
        track = aPcb->m_SegZoneDeprecated.GetLast();
    else
        track = aPcb->m_Track.GetLast();

    for( ; track;  track = track->Back() )
    {
        if( GetNetCode() >= track->GetNetCode() )
            return track->Next();
    }

    if( Type() == PCB_ZONE_T )  // Deprecated
        return aPcb->m_SegZoneDeprecated.GetFirst();
    else
        return aPcb->m_Track.GetFirst();
}

//.........这里部分代码省略.........
                via && (via = via->GetVia( *curpos, layer )) != NULL;
                via = via->Next() )
        {
            if( via != currTrack )   // a via cannot influence itself
            {
                if( !doCheckNet || !currTrack || currTrack->GetNetCode() == via->GetNetCode() )
                {
                    *curpos = via->GetStart();
                    // D(printf("via hit\n");)
                    return true;
                }
            }
        }

        if( !currTrack )
        {
            LSET layers( layer );

            TRACK* track = m_Pcb->GetVisibleTrack( m_Pcb->m_Track, pos, layers );

            if( !track || track->Type() != PCB_TRACE_T )
            {
                // D(printf("!currTrack and track=%p not found, layer_mask=0x%X\n", track, layer_mask );)
                return false;
            }

            // D( printf( "Project\n" ); )
            return Project( curpos, on_grid, track );
        }

        /*
         * In two segment mode, ignore the final segment if it's inside a grid square.
         */
        if( !amMovingVia && currTrack && g_TwoSegmentTrackBuild && currTrack->Back()
            && currTrack->GetStart().x - aGridSize.x < currTrack->GetEnd().x
            && currTrack->GetStart().x + aGridSize.x > currTrack->GetEnd().x
            && currTrack->GetStart().y - aGridSize.y < currTrack->GetEnd().y
            && currTrack->GetStart().y + aGridSize.y > currTrack->GetEnd().y )
        {
            currTrack = currTrack->Back();
        }


        for( TRACK* track = m_Pcb->m_Track; track; track = track->Next() )
        {
            if( track->Type() != PCB_TRACE_T )
                continue;

            if( doCheckNet && currTrack && currTrack->GetNetCode() != track->GetNetCode() )
                continue;

            if( m_Pcb->IsLayerVisible( track->GetLayer() ) == false )
                continue;

            // omit the layer check if moving a via
            if( !amMovingVia && !track->IsOnLayer( layer ) )
                continue;

            if( !track->HitTest( *curpos ) )
                continue;

            // D(printf( "have track prospect\n");)

            if( Join( curpos, track->GetStart(), track->GetEnd(), currTrack->GetStart(), currTrack->GetEnd() ) )
            {
                // D(printf( "join currTrack->Type()=%d\n", currTrack->Type() );)

TRACK* TRACK::GetTrack( TRACK* aStartTrace, TRACK* aEndTrace, ENDPOINT_T aEndPoint,
        bool aSameNetOnly, bool aSequential )
{
    const wxPoint &position = GetEndPoint( aEndPoint );
    LAYER_MSK refLayers = GetLayerMask();
    TRACK *previousSegment;
    TRACK *nextSegment;

    if( aSequential )
    {
        // Simple sequential search: from aStartTrace forward to aEndTrace
        previousSegment = NULL;
        nextSegment = aStartTrace;
    }
    else
    {
        /* Local bidirectional search: from this backward to aStartTrace
         * AND forward to aEndTrace. The idea is that nearest segments
         * are found (on average) faster in this way. In fact same-net
         * segments are almost guaranteed to be found faster, in a global
         * search, since they are grouped together in the track list */
        previousSegment = this;
        nextSegment = this;
    }

    while( nextSegment || previousSegment )
    {
        // Terminate the search in the direction if the netcode mismatches
        if( aSameNetOnly )
        {
            if( nextSegment && (nextSegment->GetNetCode() != GetNetCode()) )
                nextSegment = NULL;
            if( previousSegment && (previousSegment->GetNetCode() != GetNetCode()) )
                previousSegment = NULL;
        }

        if( nextSegment )
        {
            if ( (nextSegment != this) &&
                 !nextSegment->GetState( BUSY | IS_DELETED ) &&
                 (refLayers & nextSegment->GetLayerMask()) )
            {
                if( (position == nextSegment->m_Start) ||
                    (position == nextSegment->m_End) )
                    return nextSegment;
            }

            // Keep looking forward
            if( nextSegment == aEndTrace )
                nextSegment = NULL;
            else
                nextSegment = nextSegment->Next();
        }

        // Same as above, looking back. During sequential search this branch is inactive
        if( previousSegment )
        {
            if ( (previousSegment != this) &&
                 !previousSegment->GetState( BUSY | IS_DELETED ) &&
                 (refLayers & previousSegment->GetLayerMask()) )
            {
                if( (position == previousSegment->m_Start) ||
                    (position == previousSegment->m_End) )
                    return previousSegment;
            }

            if( previousSegment == aStartTrace )
                previousSegment = NULL;
            else
                previousSegment = previousSegment->Back();
        }
    }

    return NULL;
}