/* ScummVM - Graphic Adventure Engine * * ScummVM is the legal property of its developers, whose names * are too numerous to list here. Please refer to the COPYRIGHT * file distributed with this source distribution. * * 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. * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * $URL$ * $Id$ * */ /* Song iterators */ #include "common/util.h" #include "sci/sci.h" #include "sci/sfx/iterator_internal.h" #include "sci/engine/state.h" // for sfx_player_tell_synth :/ #include "sci/sfx/core.h" // for sfx_player_tell_synth #include "sound/audiostream.h" #include "sound/mixer.h" namespace Sci { static const int MIDI_cmdlen[16] = {0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 1, 1, 2, 0 }; /*#define DEBUG_DECODING*/ /*#define DEBUG_VERBOSE*/ /** Find first set bit in bits and return its index. Returns 0 if bits is 0. */ static int sci_ffs(int bits) { if (!bits) return 0; int retval = 1; while (!(bits & 1)) { retval++; bits >>= 1; } return retval; } static void print_tabs_id(int nr, songit_id_t id) { while (nr-- > 0) fprintf(stderr, "\t"); fprintf(stderr, "[%08lx] ", id); } BaseSongIterator::BaseSongIterator(byte *data, uint size, songit_id_t id) : _data(data, size) { ID = id; } /************************************/ /*-- SCI0 iterator implementation --*/ /************************************/ #define SCI0_MIDI_OFFSET 33 #define SCI0_END_OF_SONG 0xfc /* proprietary MIDI command */ #define SCI0_PCM_SAMPLE_RATE_OFFSET 0x0e #define SCI0_PCM_SIZE_OFFSET 0x20 #define SCI0_PCM_DATA_OFFSET 0x2c #define CHECK_FOR_END_ABSOLUTE(offset) \ if (offset > _data.size()) { \ warning("Reached end of song without terminator (%x/%x) at %d", offset, _data.size(), __LINE__); \ return SI_FINISHED; \ } #define CHECK_FOR_END(offset_augment) \ if ((channel->offset + (offset_augment)) > channel->end) { \ channel->state = SI_STATE_FINISHED; \ warning("Reached end of track %d without terminator (%x+%x/%x) at %d", channel->id, channel->offset, offset_augment, channel->end, __LINE__); \ return SI_FINISHED; \ } static int _parse_ticks(byte *data, int *offset_p, int size) { int ticks = 0; int tempticks; int offset = 0; do { tempticks = data[offset++]; ticks += (tempticks == SCI_MIDI_TIME_EXPANSION_PREFIX) ? SCI_MIDI_TIME_EXPANSION_LENGTH : tempticks; } while (tempticks == SCI_MIDI_TIME_EXPANSION_PREFIX && offset < size); if (offset_p) *offset_p = offset; return ticks; } static int _sci0_get_pcm_data(Sci0SongIterator *self, sfx_pcm_config_t *format, int *xoffset, uint *xsize); #define PARSE_FLAG_LOOPS_UNLIMITED (1 << 0) /* Unlimited # of loops? */ #define PARSE_FLAG_PARAMETRIC_CUE (1 << 1) /* Assume that cues take an additional "cue value" argument */ /* This implements a difference between SCI0 and SCI1 cues. */ void SongIteratorChannel::init(int id_, int offset_, int end_) { playmask = PLAYMASK_NONE; /* Disable all channels */ id = id_; notes_played = 0; state = SI_STATE_DELTA_TIME; loop_timepos = 0; total_timepos = 0; timepos_increment = 0; delay = 0; /* Only used for more than one channel */ last_cmd = 0xfe; offset = loop_offset = initial_offset = offset_; end = end_; saw_notes = 0; } void SongIteratorChannel::resetSynthChannels() { byte buf[5]; // FIXME: Evil hack SfxState &sound = ((SciEngine*)g_engine)->getEngineState()->_sound; for (int i = 0; i < MIDI_CHANNELS; i++) { if (playmask & (1 << i)) { buf[0] = 0xe0 | i; /* Pitch bend */ buf[1] = 0x80; /* Wheel center */ buf[2] = 0x40; sound.sfx_player_tell_synth(3, buf); buf[0] = 0xb0 | i; // Set control buf[1] = 0x40; // Hold pedal buf[2] = 0x00; // Off sound.sfx_player_tell_synth(3, buf); /* TODO: Reset other controls? */ } } } int BaseSongIterator::parseMidiCommand(byte *buf, int *result, SongIteratorChannel *channel, int flags) { byte cmd; int paramsleft; int midi_op; int midi_channel; channel->state = SI_STATE_DELTA_TIME; cmd = _data[channel->offset++]; if (!(cmd & 0x80)) { /* 'Running status' mode */ channel->offset--; cmd = channel->last_cmd; } if (cmd == 0xfe) { warning("song iterator subsystem: Corrupted sound resource detected."); return SI_FINISHED; } midi_op = cmd >> 4; midi_channel = cmd & 0xf; paramsleft = MIDI_cmdlen[midi_op]; channel->saw_notes |= 1 << midi_channel; #if 0 if (1) { fprintf(stderr, "[IT]: off=%x, cmd=%02x, takes %d args ", channel->offset - 1, cmd, paramsleft); fprintf(stderr, "[%02x %02x <%02x> %02x %02x %02x]\n", _data[channel->offset-3], _data[channel->offset-2], _data[channel->offset-1], _data[channel->offset], _data[channel->offset+1], _data[channel->offset+2]); } #endif buf[0] = cmd; CHECK_FOR_END(paramsleft); memcpy(buf + 1, _data.begin() + channel->offset, paramsleft); *result = 1 + paramsleft; channel->offset += paramsleft; channel->last_cmd = cmd; /* Are we supposed to play this channel? */ if ( /* First, exclude "global" properties-- such as cues-- from consideration */ (midi_op < 0xf && !(cmd == SCI_MIDI_SET_SIGNAL) && !(SCI_MIDI_CONTROLLER(cmd) && buf[1] == SCI_MIDI_CUMULATIVE_CUE)) /* Next, check if the channel is allowed */ && (!((1 << midi_channel) & channel->playmask))) return /* Execute next command */ nextCommand(buf, result); if (cmd == SCI_MIDI_EOT) { /* End of track? */ channel->resetSynthChannels(); /* fprintf(stderr, "eot; loops = %d, notesplayed=%d\n", loops, channel->notes_played);*/ if (_loops > 1 /* && channel->notes_played*/) { /* If allowed, decrement the number of loops */ if (!(flags & PARSE_FLAG_LOOPS_UNLIMITED)) *result = --_loops; #ifdef DEBUG_DECODING fprintf(stderr, "%s L%d: (%p):%d Looping ", __FILE__, __LINE__, this, channel->id); if (flags & PARSE_FLAG_LOOPS_UNLIMITED) fprintf(stderr, "(indef.)"); else fprintf(stderr, "(%d)", _loops); fprintf(stderr, " %x -> %x\n", channel->offset, channel->loop_offset); #endif channel->offset = channel->loop_offset; channel->notes_played = 0; channel->state = SI_STATE_DELTA_TIME; channel->total_timepos = channel->loop_timepos; channel->last_cmd = 0xfe; debugC(2, kDebugLevelSound, "Looping song iterator %08lx.\n", ID); return SI_LOOP; } else { channel->state = SI_STATE_FINISHED; #ifdef DEBUG_DECODING fprintf(stderr, "%s L%d: (%p):%d EOT because" " %d notes, %d loops\n", __FILE__, __LINE__, this, channel->id, channel->notes_played, _loops); #endif return SI_FINISHED; } } else if (cmd == SCI_MIDI_SET_SIGNAL) { if (buf[1] == SCI_MIDI_SET_SIGNAL_LOOP) { channel->loop_offset = channel->offset; channel->loop_timepos = channel->total_timepos; return /* Execute next command */ nextCommand(buf, result); } else { /* Used to be conditional <= 127 */ *result = buf[1]; /* Absolute cue */ return SI_ABSOLUTE_CUE; } } else if (SCI_MIDI_CONTROLLER(cmd)) { switch (buf[1]) { case SCI_MIDI_CUMULATIVE_CUE: if (flags & PARSE_FLAG_PARAMETRIC_CUE) _ccc += buf[2]; else { /* No parameter to CC */ _ccc++; /* channel->offset--; */ } *result = _ccc; return SI_RELATIVE_CUE; case SCI_MIDI_RESET_ON_SUSPEND: _resetflag = buf[2]; break; case SCI_MIDI_SET_POLYPHONY: _polyphony[midi_channel] = buf[2]; #if 0 { Sci1SongIterator *self1 = (Sci1SongIterator *)this; int i; int voices = 0; for (i = 0; i < self1->_numChannels; i++) { voices += _polyphony[i]; } printf("SET_POLYPHONY(%d, %d) for a total of %d voices\n", midi_channel, buf[2], voices); printf("[iterator] DEBUG: Polyphony = [ "); for (i = 0; i < self1->_numChannels; i++) printf("%d ", _polyphony[i]); printf("]\n"); printf("[iterator] DEBUG: Importance = [ "); for (i = 0; i < self1->_numChannels; i++) printf("%d ", _importance[i]); printf("]\n"); } #endif break; case SCI_MIDI_SET_REVERB: break; case SCI_MIDI_CHANNEL_MUTE: warning("CHANNEL_MUTE(%d, %d)", midi_channel, buf[2]); break; case SCI_MIDI_HOLD: { // Safe cast: This controller is only used in SCI1 Sci1SongIterator *self1 = (Sci1SongIterator *)this; if (buf[2] == self1->_hold) { channel->offset = channel->initial_offset; channel->notes_played = 0; channel->state = SI_STATE_COMMAND; channel->total_timepos = 0; self1->_numLoopedChannels = self1->_numActiveChannels - 1; // FIXME: // This implementation of hold breaks getting out of the // limo when visiting the airport near the start of LSL5. // It seems like all channels should be reset here somehow, // but not sure how. // Forcing all channel offsets to 0 seems to fix the hang, // but somehow slows the exit sequence down to take 20 seconds // instead of about 3. return SI_LOOP; } break; } case 0x04: /* UNKNOWN NYI (happens in LSL2 gameshow) */ case 0x46: /* UNKNOWN NYI (happens in LSL3 binoculars) */ case 0x61: /* UNKNOWN NYI (special for adlib? Iceman) */ case 0x73: /* UNKNOWN NYI (happens in Hoyle) */ case 0xd1: /* UNKNOWN NYI (happens in KQ4 when riding the unicorn) */ return /* Execute next command */ nextCommand(buf, result); case 0x01: /* modulation */ case 0x07: /* volume */ case 0x0a: /* panpot */ case 0x0b: /* expression */ case 0x40: /* hold */ case 0x79: /* reset all */ /* No special treatment neccessary */ break; } return 0; } else { if ((cmd & 0xf0) == 0x90) /* note on? */ channel->notes_played++; #if 0 /* Perform remapping, if neccessary */ if (cmd != SCI_MIDI_SET_SIGNAL && cmd < 0xf0) { /* Not a generic command */ int chan = cmd & 0xf; int op = cmd & 0xf0; chan = channel_remap[chan]; buf[0] = chan | op; } #endif /* Process as normal MIDI operation */ return 0; } } int BaseSongIterator::processMidi(byte *buf, int *result, SongIteratorChannel *channel, int flags) { CHECK_FOR_END(0); switch (channel->state) { case SI_STATE_PCM: { if (_data[channel->offset] == 0 && _data[channel->offset + 1] == SCI_MIDI_EOT) /* Fake one extra tick to trick the interpreter into not killing the song iterator right away */ channel->state = SI_STATE_PCM_MAGIC_DELTA; else channel->state = SI_STATE_DELTA_TIME; return SI_PCM; } case SI_STATE_PCM_MAGIC_DELTA: { sfx_pcm_config_t format; int offset; uint size; int delay; if (_sci0_get_pcm_data((Sci0SongIterator *)this, &format, &offset, &size)) return SI_FINISHED; /* 'tis broken */ channel->state = SI_STATE_FINISHED; delay = (size * 50 + format.rate - 1) / format.rate; /* number of ticks to completion*/ debugC(2, kDebugLevelSound, "delaying %d ticks\n", delay); return delay; } case SI_STATE_UNINITIALISED: warning("Attempt to read command from uninitialized iterator"); init(); return nextCommand(buf, result); case SI_STATE_FINISHED: return SI_FINISHED; case SI_STATE_DELTA_TIME: { int offset; int ticks = _parse_ticks(_data.begin() + channel->offset, &offset, _data.size() - channel->offset); channel->offset += offset; channel->delay += ticks; channel->timepos_increment = ticks; CHECK_FOR_END(0); channel->state = SI_STATE_COMMAND; if (ticks) return ticks; } /* continute otherwise... */ case SI_STATE_COMMAND: { int retval; channel->total_timepos += channel->timepos_increment; channel->timepos_increment = 0; retval = parseMidiCommand(buf, result, channel, flags); if (retval == SI_FINISHED) { if (_numActiveChannels) --(_numActiveChannels); #ifdef DEBUG_DECODING fprintf(stderr, "%s L%d: (%p):%d Finished channel, %d channels left\n", __FILE__, __LINE__, this, channel->id, _numActiveChannels); #endif /* If we still have channels left... */ if (_numActiveChannels) { return nextCommand(buf, result); } /* Otherwise, we have reached the end */ _loops = 0; } return retval; } default: error("Invalid iterator state %d", channel->state); return SI_FINISHED; } } int Sci0SongIterator::nextCommand(byte *buf, int *result) { return processMidi(buf, result, &_channel, PARSE_FLAG_PARAMETRIC_CUE); } static int _sci0_header_magic_p(byte *data, int offset, int size) { if (offset + 0x10 > size) return 0; return (data[offset] == 0x1a) && (data[offset + 1] == 0x00) && (data[offset + 2] == 0x01) && (data[offset + 3] == 0x00); } static int _sci0_get_pcm_data(Sci0SongIterator *self, sfx_pcm_config_t *format, int *xoffset, uint *xsize) { int tries = 2; bool found_it = false; byte *pcm_data; int size; uint offset = SCI0_MIDI_OFFSET; if (self->_data[0] != 2) return 1; /* No such luck */ while ((tries--) && (offset < self->_data.size()) && (!found_it)) { // Search through the garbage manually // FIXME: Replace offset by an iterator Common::Array::iterator iter = Common::find(self->_data.begin() + offset, self->_data.end(), SCI0_END_OF_SONG); if (iter == self->_data.end()) { warning("Playing unterminated song"); return 1; } // add one to move it past the END_OF_SONG marker iter++; offset = iter - self->_data.begin(); // FIXME if (_sci0_header_magic_p(self->_data.begin(), offset, self->_data.size())) found_it = true; } if (!found_it) { warning("Song indicates presence of PCM, but" " none found (finally at offset %04x)", offset); return 1; } pcm_data = self->_data.begin() + offset; size = READ_LE_UINT16(pcm_data + SCI0_PCM_SIZE_OFFSET); /* Two of the format parameters are fixed by design: */ format->format = SFX_PCM_FORMAT_U8; format->stereo = SFX_PCM_MONO; format->rate = READ_LE_UINT16(pcm_data + SCI0_PCM_SAMPLE_RATE_OFFSET); if (offset + SCI0_PCM_DATA_OFFSET + size != self->_data.size()) { int d = offset + SCI0_PCM_DATA_OFFSET + size - self->_data.size(); warning("PCM advertizes %d bytes of data, but %d" " bytes are trailing in the resource", size, self->_data.size() - (offset + SCI0_PCM_DATA_OFFSET)); if (d > 0) size -= d; /* Fix this */ } *xoffset = offset; *xsize = size; return 0; } static Audio::AudioStream *makeStream(byte *data, int size, sfx_pcm_config_t conf) { debugC(2, kDebugLevelSound, "Playing PCM data of size %d, rate %d\n", size, conf.rate); // Duplicate the data byte *sound = (byte *)malloc(size); memcpy(sound, data, size); // Convert stream format flags int flags = Audio::Mixer::FLAG_AUTOFREE; if (conf.format == SFX_PCM_FORMAT_U8) flags |= Audio::Mixer::FLAG_UNSIGNED; else if (conf.format == SFX_PCM_FORMAT_S16_NATIVE) { flags |= Audio::Mixer::FLAG_16BITS; #ifndef SCUMM_BIG_ENDIAN flags |= Audio::Mixer::FLAG_LITTLE_ENDIAN; #endif } if (conf.stereo) flags |= Audio::Mixer::FLAG_STEREO; return Audio::makeLinearInputStream(sound, size, conf.rate, flags, 0, 0); } Audio::AudioStream *Sci0SongIterator::getAudioStream() { sfx_pcm_config_t conf; int offset; uint size; if (_sci0_get_pcm_data(this, &conf, &offset, &size)) return NULL; _channel.state = SI_STATE_FINISHED; /* Don't play both PCM and music */ return makeStream(_data.begin() + offset + SCI0_PCM_DATA_OFFSET, size, conf); } SongIterator *Sci0SongIterator::handleMessage(Message msg) { if (msg._class == _SIMSG_BASE) { switch (msg._type) { case _SIMSG_BASEMSG_PRINT: print_tabs_id(msg._arg.i, ID); debugC(2, kDebugLevelSound, "SCI0: dev=%d, active-chan=%d, size=%d, loops=%d\n", _deviceId, _numActiveChannels, _data.size(), _loops); break; case _SIMSG_BASEMSG_SET_LOOPS: _loops = msg._arg.i; break; case _SIMSG_BASEMSG_STOP: { songit_id_t sought_id = msg.ID; if (sought_id == ID) _channel.state = SI_STATE_FINISHED; break; } case _SIMSG_BASEMSG_SET_PLAYMASK: { int i; _deviceId = msg._arg.i; /* Set all but the rhytm channel mask bits */ _channel.playmask &= ~(1 << MIDI_RHYTHM_CHANNEL); for (i = 0; i < MIDI_CHANNELS; i++) if (_data[2 + (i << 1)] & _deviceId && i != MIDI_RHYTHM_CHANNEL) _channel.playmask |= (1 << i); } break; case _SIMSG_BASEMSG_SET_RHYTHM: _channel.playmask &= ~(1 << MIDI_RHYTHM_CHANNEL); if (msg._arg.i) _channel.playmask |= (1 << MIDI_RHYTHM_CHANNEL); break; case _SIMSG_BASEMSG_SET_FADE: { fade_params_t *fp = (fade_params_t *) msg._arg.p; fade.action = fp->action; fade.final_volume = fp->final_volume; fade.ticks_per_step = fp->ticks_per_step; fade.step_size = fp->step_size; break; } default: return NULL; } return this; } return NULL; } int Sci0SongIterator::getTimepos() { return _channel.total_timepos; } Sci0SongIterator::Sci0SongIterator(byte *data, uint size, songit_id_t id) : BaseSongIterator(data, size, id) { channel_mask = 0xffff; // Allocate all channels by default _channel.state = SI_STATE_UNINITIALISED; for (int i = 0; i < MIDI_CHANNELS; i++) _polyphony[i] = data[1 + (i << 1)]; init(); } void Sci0SongIterator::init() { fade.action = FADE_ACTION_NONE; _resetflag = 0; _loops = 0; priority = 0; _ccc = 0; /* Reset cumulative cue counter */ _numActiveChannels = 1; _channel.init(0, SCI0_MIDI_OFFSET, _data.size()); _channel.resetSynthChannels(); if (_data[0] == 2) /* Do we have an embedded PCM? */ _channel.state = SI_STATE_PCM; } SongIterator *Sci0SongIterator::clone(int delta) { Sci0SongIterator *newit = new Sci0SongIterator(*this); return newit; } /***************************/ /*-- SCI1 song iterators --*/ /***************************/ #define SCI01_INVALID_DEVICE 0xff /* Second index determines whether PCM output is supported */ static const int sci0_to_sci1_device_map[][2] = { {0x06, 0x0c}, /* MT-32 */ {0xff, 0xff}, /* YM FB-01 */ {0x00, 0x00}, /* CMS/Game Blaster-- we assume OPL/2 here... */ {0xff, 0xff}, /* Casio MT540/CT460 */ {0x13, 0x13}, /* Tandy 3-voice */ {0x12, 0x12}, /* PC speaker */ {0xff, 0xff}, {0xff, 0xff}, }; /* Maps bit number to device ID */ int Sci1SongIterator::initSample(const int offset) { Sci1Sample sample; int rate; int length; int begin; int end; CHECK_FOR_END_ABSOLUTE((uint)offset + 10); if (_data[offset + 1] != 0) warning("[iterator-1] In sample at offset 0x04x: Byte #1 is %02x instead of zero", _data[offset + 1]); rate = (int16)READ_LE_UINT16(_data.begin() + offset + 2); length = READ_LE_UINT16(_data.begin() + offset + 4); begin = (int16)READ_LE_UINT16(_data.begin() + offset + 6); end = (int16)READ_LE_UINT16(_data.begin() + offset + 8); CHECK_FOR_END_ABSOLUTE((uint)(offset + 10 + length)); sample.delta = begin; sample.size = length; sample._data = _data.begin() + offset + 10; #ifdef DEBUG_VERBOSE fprintf(stderr, "[SAMPLE] %x/%x/%x/%x l=%x\n", offset + 10, begin, end, _data.size(), length); #endif sample.format.format = SFX_PCM_FORMAT_U8; sample.format.stereo = SFX_PCM_MONO; sample.format.rate = rate; sample.announced = false; /* Insert into the sample list at the right spot, keeping it sorted by delta */ Common::List::iterator seeker = _samples.begin(); while (seeker != _samples.end() && seeker->delta < begin) ++seeker; _samples.insert(seeker, sample); return 0; /* Everything's fine */ } int Sci1SongIterator::initSong() { int last_time; uint offset = 0; _numChannels = 0; _samples.clear(); // _deviceId = 0x0c; if (_data[offset] == 0xf0) { priority = _data[offset + 1]; offset += 8; } while (_data[offset] != 0xff && _data[offset] != _deviceId) { offset++; CHECK_FOR_END_ABSOLUTE(offset + 1); while (_data[offset] != 0xff) { CHECK_FOR_END_ABSOLUTE(offset + 7); offset += 6; } offset++; } if (_data[offset] == 0xff) { warning("[iterator] Song does not support hardware 0x%02x", _deviceId); return 1; } offset++; while (_data[offset] != 0xff) { /* End of list? */ uint track_offset; int end; offset += 2; CHECK_FOR_END_ABSOLUTE(offset + 4); track_offset = READ_LE_UINT16(_data.begin() + offset); end = READ_LE_UINT16(_data.begin() + offset + 2); CHECK_FOR_END_ABSOLUTE(track_offset - 1); if (_data[track_offset] == 0xfe) { if (initSample(track_offset)) return 1; /* Error */ } else { /* Regular MIDI channel */ if (_numChannels >= MIDI_CHANNELS) { warning("[iterator] Song has more than %d channels, cutting them off", MIDI_CHANNELS); break; /* Scan for remaining samples */ } else { int channel_nr = _data[track_offset] & 0xf; SongIteratorChannel &channel = _channels[_numChannels++]; /* if (_data[track_offset] & 0xf0) printf("Channel %d has mapping bits %02x\n", channel_nr, _data[track_offset] & 0xf0); */ // Add 2 to skip over header bytes */ channel.init(channel_nr, track_offset + 2, track_offset + end); channel.resetSynthChannels(); _polyphony[_numChannels - 1] = _data[channel.offset - 1] & 15; _importance[_numChannels - 1] = _data[channel.offset - 1] >> 4; channel.playmask = ~0; /* Enable all */ channel_mask |= (1 << channel_nr); CHECK_FOR_END_ABSOLUTE(offset + end); } } offset += 4; CHECK_FOR_END_ABSOLUTE(offset); } /* Now ensure that sample deltas are relative to the previous sample */ last_time = 0; _numActiveChannels = _numChannels; _numLoopedChannels = 0; for (Common::List::iterator seeker = _samples.begin(); seeker != _samples.end(); ++seeker) { int prev_last_time = last_time; //printf("[iterator] Detected sample: %d Hz, %d bytes at time %d\n", // seeker->format.rate, seeker->size, seeker->delta); last_time = seeker->delta; seeker->delta -= prev_last_time; } return 0; /* Success */ } int Sci1SongIterator::getSmallestDelta() const { int d = -1; for (int i = 0; i < _numChannels; i++) if (_channels[i].state == SI_STATE_COMMAND && (d == -1 || _channels[i].delay < d)) d = _channels[i].delay; if (!_samples.empty() && _samples.begin()->delta < d) return _samples.begin()->delta; else return d; } void Sci1SongIterator::updateDelta(int delta) { if (!_samples.empty()) _samples.begin()->delta -= delta; for (int i = 0; i < _numChannels; i++) if (_channels[i].state == SI_STATE_COMMAND) _channels[i].delay -= delta; } bool Sci1SongIterator::noDeltaTime() const { for (int i = 0; i < _numChannels; i++) if (_channels[i].state == SI_STATE_DELTA_TIME) return false; return true; } #define COMMAND_INDEX_NONE -1 #define COMMAND_INDEX_PCM -2 int Sci1SongIterator::getCommandIndex() const { /* Determine the channel # of the next active event, or -1 */ int i; int base_delay = 0x7ffffff; int best_chan = COMMAND_INDEX_NONE; for (i = 0; i < _numChannels; i++) if ((_channels[i].state != SI_STATE_PENDING) && (_channels[i].state != SI_STATE_FINISHED)) { if ((_channels[i].state == SI_STATE_DELTA_TIME) && (_channels[i].delay == 0)) return i; /* First, read all unknown delta times */ if (_channels[i].delay < base_delay) { best_chan = i; base_delay = _channels[i].delay; } } if (!_samples.empty() && base_delay >= _samples.begin()->delta) return COMMAND_INDEX_PCM; return best_chan; } Audio::AudioStream *Sci1SongIterator::getAudioStream() { Common::List::iterator sample = _samples.begin(); if (sample != _samples.end() && sample->delta <= 0) { Audio::AudioStream *feed = makeStream(sample->_data, sample->size, sample->format); _samples.erase(sample); return feed; } else return NULL; } int Sci1SongIterator::nextCommand(byte *buf, int *result) { if (!_initialised) { //printf("[iterator] DEBUG: Initialising for %d\n", _deviceId); _initialised = true; if (initSong()) return SI_FINISHED; } if (_delayRemaining) { int delay = _delayRemaining; _delayRemaining = 0; return delay; } int retval = 0; do { /* All delays must be processed separately */ int chan = getCommandIndex(); if (chan == COMMAND_INDEX_NONE) { return SI_FINISHED; } if (chan == COMMAND_INDEX_PCM) { if (_samples.begin()->announced) { /* Already announced; let's discard it */ Audio::AudioStream *feed = getAudioStream(); delete feed; } else { int delay = _samples.begin()->delta; if (delay) { updateDelta(delay); return delay; } /* otherwise we're touching a PCM */ _samples.begin()->announced = true; return SI_PCM; } } else { /* Not a PCM */ retval = processMidi(buf, result, &(_channels[chan]), PARSE_FLAG_LOOPS_UNLIMITED); if (retval == SI_LOOP) { _numLoopedChannels++; _channels[chan].state = SI_STATE_PENDING; _channels[chan].delay = 0; if (_numLoopedChannels == _numActiveChannels) { int i; /* Everyone's ready: Let's loop */ for (i = 0; i < _numChannels; i++) if (_channels[i].state == SI_STATE_PENDING) _channels[i].state = SI_STATE_DELTA_TIME; _numLoopedChannels = 0; return SI_LOOP; } } else if (retval == SI_FINISHED) { #ifdef DEBUG fprintf(stderr, "FINISHED some channel\n"); #endif } else if (retval > 0) { int sd ; sd = getSmallestDelta(); if (noDeltaTime() && sd) { /* No other channel is ready */ updateDelta(sd); /* Only from here do we return delta times */ return sd; } } } /* Not a PCM */ } while (retval > 0); return retval; } SongIterator *Sci1SongIterator::handleMessage(Message msg) { if (msg._class == _SIMSG_BASE) { /* May extend this in the future */ switch (msg._type) { case _SIMSG_BASEMSG_PRINT: { int playmask = 0; int i; for (i = 0; i < _numChannels; i++) playmask |= _channels[i].playmask; print_tabs_id(msg._arg.i, ID); debugC(2, kDebugLevelSound, "SCI1: chan-nr=%d, playmask=%04x\n", _numChannels, playmask); } break; case _SIMSG_BASEMSG_STOP: { songit_id_t sought_id = msg.ID; int i; if (sought_id == ID) { ID = 0; for (i = 0; i < _numChannels; i++) _channels[i].state = SI_STATE_FINISHED; } break; } case _SIMSG_BASEMSG_SET_PLAYMASK: if (msg.ID == ID) { channel_mask = 0; _deviceId = sci0_to_sci1_device_map [sci_ffs(msg._arg.i & 0xff) - 1] [sfx_pcm_available()] ; if (_deviceId == 0xff) { warning("[iterator] Device %d(%d) not supported", msg._arg.i & 0xff, sfx_pcm_available()); } if (_initialised) { int i; int toffset = -1; for (i = 0; i < _numChannels; i++) if (_channels[i].state != SI_STATE_FINISHED && _channels[i].total_timepos > toffset) { toffset = _channels[i].total_timepos + _channels[i].timepos_increment - _channels[i].delay; } /* Find an active channel so that we can ** get the correct time offset */ initSong(); toffset -= _delayRemaining; _delayRemaining = 0; if (toffset > 0) return new_fast_forward_iterator(this, toffset); } else { initSong(); _initialised = true; } break; } case _SIMSG_BASEMSG_SET_LOOPS: if (msg.ID == ID) _loops = (msg._arg.i > 32767) ? 99 : 0; /* 99 is arbitrary, but we can't use '1' because of ** the way we're testing in the decoding section. */ break; case _SIMSG_BASEMSG_SET_HOLD: _hold = msg._arg.i; break; case _SIMSG_BASEMSG_SET_RHYTHM: /* Ignore */ break; case _SIMSG_BASEMSG_SET_FADE: { fade_params_t *fp = (fade_params_t *) msg._arg.p; fade.action = fp->action; fade.final_volume = fp->final_volume; fade.ticks_per_step = fp->ticks_per_step; fade.step_size = fp->step_size; break; } default: warning("Unsupported command %d to SCI1 iterator", msg._type); } return this; } return NULL; } Sci1SongIterator::Sci1SongIterator(byte *data, uint size, songit_id_t id) : BaseSongIterator(data, size, id) { channel_mask = 0; // Defer channel allocation for (int i = 0; i < MIDI_CHANNELS; i++) _polyphony[i] = 0; // Unknown init(); } void Sci1SongIterator::init() { fade.action = FADE_ACTION_NONE; _resetflag = 0; _loops = 0; priority = 0; _ccc = 0; _deviceId = 0x00; // Default to Sound Blaster/Adlib for purposes of cue computation _numChannels = 0; _initialised = false; _delayRemaining = 0; _loops = 0; _hold = 0; memset(_polyphony, 0, sizeof(_polyphony)); memset(_importance, 0, sizeof(_importance)); } Sci1SongIterator::~Sci1SongIterator() { } SongIterator *Sci1SongIterator::clone(int delta) { Sci1SongIterator *newit = new Sci1SongIterator(*this); newit->_delayRemaining = delta; return newit; } int Sci1SongIterator::getTimepos() { int max = 0; int i; for (i = 0; i < _numChannels; i++) if (_channels[i].total_timepos > max) max = _channels[i].total_timepos; return max; } /** * A song iterator with the purpose of sending notes-off channel commands. */ class CleanupSongIterator : public SongIterator { public: CleanupSongIterator(uint channels) { channel_mask = channels; ID = 17; } int nextCommand(byte *buf, int *result); Audio::AudioStream *getAudioStream() { return NULL; } SongIterator *handleMessage(Message msg); int getTimepos() { return 0; } SongIterator *clone(int delta) { return new CleanupSongIterator(*this); } }; SongIterator *CleanupSongIterator::handleMessage(Message msg) { if (msg._class == _SIMSG_BASEMSG_PRINT && msg._type == _SIMSG_BASEMSG_PRINT) { print_tabs_id(msg._arg.i, ID); debugC(2, kDebugLevelSound, "CLEANUP\n"); } return NULL; } int CleanupSongIterator::nextCommand(byte *buf, int *result) { /* Task: Return channel-notes-off for each channel */ if (channel_mask) { int bs = sci_ffs(channel_mask) - 1; channel_mask &= ~(1 << bs); buf[0] = 0xb0 | bs; /* Controller */ buf[1] = SCI_MIDI_CHANNEL_NOTES_OFF; buf[2] = 0; /* Hmm... */ *result = 3; return 0; } else return SI_FINISHED; } /**********************/ /*-- Timer iterator --*/ /**********************/ TimerSongIterator::TimerSongIterator(int delta) : _delta(delta) { } int TimerSongIterator::nextCommand(byte *buf, int *result) { if (_delta) { int d = _delta; _delta = 0; return d; } return SI_FINISHED; } SongIterator *TimerSongIterator::handleMessage(Message msg) { return NULL; } int TimerSongIterator::getTimepos() { return 0; } Audio::AudioStream *TimerSongIterator::getAudioStream() { return NULL; } SongIterator *TimerSongIterator::clone(int delta) { TimerSongIterator *newit = new TimerSongIterator(*this); return newit; } SongIterator *new_timer_iterator(int delta) { return new TimerSongIterator(delta); } /**********************************/ /*-- Fast-forward song iterator --*/ /**********************************/ int FastForwardSongIterator::nextCommand(byte *buf, int *result) { if (_delta <= 0) return SI_MORPH; /* Did our duty */ while (1) { int rv = _delegate->nextCommand(buf, result); if (rv > 0) { /* Subtract from the delta we want to wait */ _delta -= rv; /* Done */ if (_delta < 0) return -_delta; } if (rv <= 0) return rv; } } Audio::AudioStream *FastForwardSongIterator::getAudioStream() { return _delegate->getAudioStream(); } SongIterator *FastForwardSongIterator::handleMessage(Message msg) { if (msg._class == _SIMSG_PLASTICWRAP) { assert(msg._type == _SIMSG_PLASTICWRAP_ACK_MORPH); if (_delta <= 0) { SongIterator *it = _delegate; delete this; return it; } warning("[ff-iterator] Morphing without need"); return this; } if (msg._class == _SIMSG_BASE && msg._type == _SIMSG_BASEMSG_PRINT) { print_tabs_id(msg._arg.i, ID); debugC(2, kDebugLevelSound, "FASTFORWARD:\n"); msg._arg.i++; } // And continue with the delegate songit_handle_message(&_delegate, msg); return NULL; } int FastForwardSongIterator::getTimepos() { return _delegate->getTimepos(); } FastForwardSongIterator::FastForwardSongIterator(SongIterator *capsit, int delta) : _delegate(capsit), _delta(delta) { channel_mask = capsit->channel_mask; } SongIterator *FastForwardSongIterator::clone(int delta) { FastForwardSongIterator *newit = new FastForwardSongIterator(*this); newit->_delegate = _delegate->clone(delta); return newit; } SongIterator *new_fast_forward_iterator(SongIterator *capsit, int delta) { if (capsit == NULL) return NULL; FastForwardSongIterator *it = new FastForwardSongIterator(capsit, delta); return it; } /********************/ /*-- Tee iterator --*/ /********************/ static void song_iterator_add_death_listener(SongIterator *it, TeeSongIterator *client) { for (int i = 0; i < SONGIT_MAX_LISTENERS; ++i) { if (it->_deathListeners[i] == 0) { it->_deathListeners[i] = client; return; } } error("FATAL: Too many death listeners for song iterator"); } static void song_iterator_remove_death_listener(SongIterator *it, TeeSongIterator *client) { for (int i = 0; i < SONGIT_MAX_LISTENERS; ++i) { if (it->_deathListeners[i] == client) { it->_deathListeners[i] = 0; return; } } } static void song_iterator_transfer_death_listeners(SongIterator *it, SongIterator *it_from) { for (int i = 0; i < SONGIT_MAX_LISTENERS; ++i) { if (it_from->_deathListeners[i]) song_iterator_add_death_listener(it, it_from->_deathListeners[i]); it_from->_deathListeners[i] = 0; } } static void songit_tee_death_notification(TeeSongIterator *self, SongIterator *corpse) { if (corpse == self->_children[TEE_LEFT].it) { self->_status &= ~TEE_LEFT_ACTIVE; self->_children[TEE_LEFT].it = NULL; } else if (corpse == self->_children[TEE_RIGHT].it) { self->_status &= ~TEE_RIGHT_ACTIVE; self->_children[TEE_RIGHT].it = NULL; } else { error("songit_tee_death_notification() failed: Breakpoint in %s, line %d", __FILE__, __LINE__); } } TeeSongIterator::TeeSongIterator(SongIterator *left, SongIterator *right) { int i; int firstfree = 1; /* First free channel */ int incomplete_map = 0; _readyToMorph = false; _status = TEE_LEFT_ACTIVE | TEE_RIGHT_ACTIVE; _children[TEE_LEFT].it = left; _children[TEE_RIGHT].it = right; /* Default to lhs channels */ channel_mask = left->channel_mask; for (i = 0; i < 16; i++) if (channel_mask & (1 << i) & right->channel_mask && (i != MIDI_RHYTHM_CHANNEL) /* Share rhythm */) { /*conflict*/ while ((firstfree == MIDI_RHYTHM_CHANNEL) /* Either if it's the rhythm channel or if it's taken */ || (firstfree < MIDI_CHANNELS && ((1 << firstfree) & channel_mask))) ++firstfree; if (firstfree == MIDI_CHANNELS) { incomplete_map = 1; //warning("[songit-tee <%08lx,%08lx>] Could not remap right channel #%d: Out of channels", // left->ID, right->ID, i); } else { _children[TEE_RIGHT].it->channel_remap[i] = firstfree; channel_mask |= (1 << firstfree); } } #ifdef DEBUG_TEE_ITERATOR if (incomplete_map) { int c; fprintf(stderr, "[songit-tee <%08lx,%08lx>] Channels:" " %04x <- %04x | %04x\n", left->ID, right->ID, channel_mask, left->channel_mask, right->channel_mask); for (c = 0 ; c < 2; c++) for (i = 0 ; i < 16; i++) fprintf(stderr, " map [%d][%d] -> %d\n", c, i, _children[c].it->channel_remap[i]); } #endif song_iterator_add_death_listener(left, this); song_iterator_add_death_listener(right, this); } TeeSongIterator::~TeeSongIterator() { // When we die, remove any listeners from our children if (_children[TEE_LEFT].it) { song_iterator_remove_death_listener(_children[TEE_LEFT].it, this); } if (_children[TEE_RIGHT].it) { song_iterator_remove_death_listener(_children[TEE_RIGHT].it, this); } } int TeeSongIterator::nextCommand(byte *buf, int *result) { static const int ready_masks[2] = {TEE_LEFT_READY, TEE_RIGHT_READY}; static const int active_masks[2] = {TEE_LEFT_ACTIVE, TEE_RIGHT_ACTIVE}; static const int pcm_masks[2] = {TEE_LEFT_PCM, TEE_RIGHT_PCM}; int i; int retid; #ifdef DEBUG_TEE_ITERATOR fprintf(stderr, "[Tee] %02x\n", _status); #endif if (!(_status & (TEE_LEFT_ACTIVE | TEE_RIGHT_ACTIVE))) /* None is active? */ return SI_FINISHED; if (_readyToMorph) return SI_MORPH; if ((_status & (TEE_LEFT_ACTIVE | TEE_RIGHT_ACTIVE)) != (TEE_LEFT_ACTIVE | TEE_RIGHT_ACTIVE)) { /* Not all are is active? */ int which = 0; #ifdef DEBUG_TEE_ITERATOR fprintf(stderr, "\tRequesting transformation...\n"); #endif if (_status & TEE_LEFT_ACTIVE) which = TEE_LEFT; else if (_status & TEE_RIGHT_ACTIVE) which = TEE_RIGHT; memcpy(buf, _children[which].buf, sizeof(buf)); *result = _children[which].result; _readyToMorph = true; return _children[which].retval; } /* First, check for unreported PCMs */ for (i = TEE_LEFT; i <= TEE_RIGHT; i++) if ((_status & (ready_masks[i] | pcm_masks[i])) == (ready_masks[i] | pcm_masks[i])) { _status &= ~ready_masks[i]; return SI_PCM; } for (i = TEE_LEFT; i <= TEE_RIGHT; i++) if (!(_status & ready_masks[i])) { /* Buffers aren't ready yet */ _children[i].retval = songit_next(&(_children[i].it), _children[i].buf, &(_children[i].result), IT_READER_MASK_ALL | IT_READER_MAY_FREE | IT_READER_MAY_CLEAN); _status |= ready_masks[i]; #ifdef DEBUG_TEE_ITERATOR fprintf(stderr, "\t Must check %d: %d\n", i, _children[i].retval); #endif if (_children[i].retval == SI_ABSOLUTE_CUE || _children[i].retval == SI_RELATIVE_CUE) return _children[i].retval; if (_children[i].retval == SI_FINISHED) { _status &= ~active_masks[i]; /* Recurse to complete */ #ifdef DEBUG_TEE_ITERATOR fprintf(stderr, "\t Child %d signalled completion, recursing w/ status %02x\n", i, _status); #endif return nextCommand(buf, result); } else if (_children[i].retval == SI_PCM) { _status |= pcm_masks[i]; _status &= ~ready_masks[i]; return SI_PCM; } } /* We've already handled PCM, MORPH and FINISHED, CUEs & LOOP remain */ retid = TEE_LEFT; if ((_children[TEE_LEFT].retval > 0) /* Asked to delay */ && (_children[TEE_RIGHT].retval <= _children[TEE_LEFT].retval)) /* Is not delaying or not delaying as much */ retid = TEE_RIGHT; #ifdef DEBUG_TEE_ITERATOR fprintf(stderr, "\tl:%d / r:%d / chose %d\n", _children[TEE_LEFT].retval, _children[TEE_RIGHT].retval, retid); #endif /* Adjust delta times */ if (_children[retid].retval > 0 && _children[1-retid].retval > 0) { if (_children[1-retid].retval == _children[retid].retval) /* If both _children wait the same amount of time, ** we have to re-fetch commands from both */ _status &= ~ready_masks[1-retid]; else /* If they don't, we can/must re-use the other ** child's delay time */ _children[1-retid].retval -= _children[retid].retval; } _status &= ~ready_masks[retid]; memcpy(buf, _children[retid].buf, sizeof(buf)); *result = _children[retid].result; return _children[retid].retval; } Audio::AudioStream *TeeSongIterator::getAudioStream() { static const int pcm_masks[2] = {TEE_LEFT_PCM, TEE_RIGHT_PCM}; int i; for (i = TEE_LEFT; i <= TEE_RIGHT; i++) if (_status & pcm_masks[i]) { _status &= ~pcm_masks[i]; return _children[i].it->getAudioStream(); } return NULL; // No iterator } SongIterator *TeeSongIterator::handleMessage(Message msg) { if (msg._class == _SIMSG_PLASTICWRAP) { assert(msg._type == _SIMSG_PLASTICWRAP_ACK_MORPH); SongIterator *old_it; if (!(_status & (TEE_LEFT_ACTIVE | TEE_RIGHT_ACTIVE))) { delete this; return NULL; } else if (!(_status & TEE_LEFT_ACTIVE)) { delete _children[TEE_LEFT].it; _children[TEE_LEFT].it = 0; old_it = _children[TEE_RIGHT].it; song_iterator_remove_death_listener(old_it, this); song_iterator_transfer_death_listeners(old_it, this); delete this; return old_it; } else if (!(_status & TEE_RIGHT_ACTIVE)) { delete _children[TEE_RIGHT].it; _children[TEE_RIGHT].it = 0; old_it = _children[TEE_LEFT].it; song_iterator_remove_death_listener(old_it, this); song_iterator_transfer_death_listeners(old_it, this); delete this; return old_it; } warning("[tee-iterator] Morphing without need"); return this; } if (msg._class == _SIMSG_BASE && msg._type == _SIMSG_BASEMSG_PRINT) { print_tabs_id(msg._arg.i, ID); debugC(2, kDebugLevelSound, "TEE:\n"); msg._arg.i++; } // And continue with the children if (_children[TEE_LEFT].it) songit_handle_message(&(_children[TEE_LEFT].it), msg); if (_children[TEE_RIGHT].it) songit_handle_message(&(_children[TEE_RIGHT].it), msg); return NULL; } void TeeSongIterator::init() { _status = TEE_LEFT_ACTIVE | TEE_RIGHT_ACTIVE; _children[TEE_LEFT].it->init(); _children[TEE_RIGHT].it->init(); } SongIterator *TeeSongIterator::clone(int delta) { TeeSongIterator *newit = new TeeSongIterator(*this); if (_children[TEE_LEFT].it) newit->_children[TEE_LEFT].it = _children[TEE_LEFT].it->clone(delta); if (_children[TEE_RIGHT].it) newit->_children[TEE_RIGHT].it = _children[TEE_RIGHT].it->clone(delta); return newit; } /*************************************/ /*-- General purpose functionality --*/ /*************************************/ int songit_next(SongIterator **it, byte *buf, int *result, int mask) { int retval; if (!*it) return SI_FINISHED; do { retval = (*it)->nextCommand(buf, result); if (retval == SI_MORPH) { debugC(2, kDebugLevelSound, " Morphing %p (stored at %p)\n", (void *)*it, (void *)it); if (!SIMSG_SEND((*it), SIMSG_ACK_MORPH)) { error("SI_MORPH failed. Breakpoint in %s, line %d", __FILE__, __LINE__); } else debugC(2, kDebugLevelSound, "SI_MORPH successful\n"); } if (retval == SI_FINISHED) debugC(2, kDebugLevelSound, "[song-iterator] Song finished. mask = %04x, cm=%04x\n", mask, (*it)->channel_mask); if (retval == SI_FINISHED && (mask & IT_READER_MAY_CLEAN) && (*it)->channel_mask) { /* This last test will fail ** with a terminated ** cleanup iterator */ int channel_mask = (*it)->channel_mask; SongIterator *old_it = *it; *it = new CleanupSongIterator(channel_mask); for(uint i = 0; i < MIDI_CHANNELS; i++) (*it)->channel_remap[i] = old_it->channel_remap[i]; song_iterator_transfer_death_listeners(*it, old_it); if (mask & IT_READER_MAY_FREE) delete old_it; retval = -9999; /* Continue */ } } while (!( /* Until one of the following holds */ (retval > 0 && (mask & IT_READER_MASK_DELAY)) || (retval == 0 && (mask & IT_READER_MASK_MIDI)) || (retval == SI_LOOP && (mask & IT_READER_MASK_LOOP)) || (retval == SI_ABSOLUTE_CUE && (mask & IT_READER_MASK_CUE)) || (retval == SI_RELATIVE_CUE && (mask & IT_READER_MASK_CUE)) || (retval == SI_PCM && (mask & IT_READER_MASK_PCM)) || (retval == SI_FINISHED) )); if (retval == SI_FINISHED && (mask & IT_READER_MAY_FREE)) { delete *it; *it = NULL; } return retval; } SongIterator::SongIterator() { ID = 0; channel_mask = 0; fade.action = FADE_ACTION_NONE; priority = 0; memset(_deathListeners, 0, sizeof(_deathListeners)); // By default, don't remap for (uint i = 0; i < 16; i++) channel_remap[i] = i; } SongIterator::SongIterator(const SongIterator &si) { ID = si.ID; channel_mask = si.channel_mask; fade = si.fade; priority = si.priority; memset(_deathListeners, 0, sizeof(_deathListeners)); for (uint i = 0; i < 16; i++) channel_remap[i] = si.channel_remap[i]; } SongIterator::~SongIterator() { for (int i = 0; i < SONGIT_MAX_LISTENERS; ++i) if (_deathListeners[i]) songit_tee_death_notification(_deathListeners[i], this); } SongIterator *songit_new(byte *data, uint size, SongIteratorType type, songit_id_t id) { BaseSongIterator *it; if (!data || size < 22) { warning("Attempt to instantiate song iterator for null song data"); return NULL; } switch (type) { case SCI_SONG_ITERATOR_TYPE_SCI0: it = new Sci0SongIterator(data, size, id); break; case SCI_SONG_ITERATOR_TYPE_SCI1: it = new Sci1SongIterator(data, size, id); break; default: /**-- Invalid/unsupported sound resources --**/ warning("Attempt to instantiate invalid/unknown song iterator type %d", type); return NULL; } return it; } int songit_handle_message(SongIterator **it_reg_p, SongIterator::Message msg) { SongIterator *it = *it_reg_p; SongIterator *newit; newit = it->handleMessage(msg); if (!newit) return 0; /* Couldn't handle */ *it_reg_p = newit; /* Might have self-morphed */ return 1; } SongIterator *sfx_iterator_combine(SongIterator *it1, SongIterator *it2) { if (it1 == NULL) return it2; if (it2 == NULL) return it1; /* Both are non-NULL: */ return new TeeSongIterator(it1, it2); } } // End of namespace Sci