/**
 * @brief Handles voice key-off triggered by gate
 * @param part Target part
 */
static inline void
koffCheck( SndDrvPart *part )
{
    // If gate already triggered, skip
    if ( part->ngo == 0 ) return;

    if ( --part->ngo == 0 || part->ngc == 2 )
    {
        u8 *adx = part->add;    // Local copy of part->add
        u8  ptx = part->ptc;    // Local copy of part->ptc

        while ( 1 )
        {
            u8 cmd = *adx;

            // Check for pattern end
            if ( cmd == 0x00 )
            {
                // If end of pattern, trigger key-off
                if ( ptx == 0 ) break;
                ptx--;

                if ( ptx == 0 ) adx = part->adt;
                else adx = part->adp;

                continue;
            }

            // If not end of pattern, try to find a note or command
            else if ( cmd < NOTE_BASE )
            {
                int i;

                for ( i = 0; i < 128; i++ )
                {
                    cmd = *( adx + i );

                    // If not note params, break
                    if ( cmd >= note_c00 ) break;
                }

                // If nothing was found, just trigger key-off
                if ( i == 128 ) break;
            }

            // If tie note, skip key-off
            if ( cmd == note_tie ) return;

            // If command is to play pattern, set adx to start of pattern
            else if ( cmd == PATX + CMD_BASE )
                adx = gft + read16( *++adx );

            // If any other command, skip past it
            else if ( cmd >= CMD_BASE )
                adx += spfp[ cmd - CMD_BASE ];

            // If anything else, trigger key-off
            else break;
        }

        // Trigger key-off for voice
        dsp->kof |= keyd;
    }
}