double BpmControl::getNearestPositionInPhase(
double dThisPosition, bool respectLoops, bool playing) {
// Without a beatgrid, we don't know the phase offset.
BeatsPointer pBeats = m_pBeats;
if (!pBeats) {
return dThisPosition;
}
SyncMode syncMode = getSyncMode();
// Master buffer is always in sync!
if (syncMode == SYNC_MASTER) {
return dThisPosition;
}
// Get the current position of this deck.
double dThisPrevBeat = m_pPrevBeat->get();
double dThisNextBeat = m_pNextBeat->get();
double dThisBeatLength;
if (dThisPosition > dThisNextBeat || dThisPosition < dThisPrevBeat) {
// There's a chance the COs might be out of date, so do a lookup.
// TODO: figure out a way so that quantized control can take care of
// this so this call isn't necessary.
if (!getBeatContext(pBeats, dThisPosition,
&dThisPrevBeat, &dThisNextBeat,
&dThisBeatLength, NULL)) {
return dThisPosition;
}
} else {
if (!getBeatContextNoLookup(dThisPosition,
dThisPrevBeat, dThisNextBeat,
&dThisBeatLength, NULL)) {
return dThisPosition;
}
}
double dOtherBeatFraction;
if (syncMode == SYNC_FOLLOWER) {
// If we're a follower, it's easy to get the other beat fraction
dOtherBeatFraction = m_dSyncTargetBeatDistance.getValue();
} else {
// If not, we have to figure it out
EngineBuffer* pOtherEngineBuffer = pickSyncTarget();
if (playing) {
if (!pOtherEngineBuffer || pOtherEngineBuffer->getSpeed() == 0.0) {
// "this" track is playing, or just starting
// only match phase if the sync target is playing as well
// else use the previouse phase of "this" track before the seek
pOtherEngineBuffer = getEngineBuffer();
}
}
if (!pOtherEngineBuffer) {
// no suitable sync buffer found
return dThisPosition;
}
TrackPointer otherTrack = pOtherEngineBuffer->getLoadedTrack();
BeatsPointer otherBeats = otherTrack ? otherTrack->getBeats() : BeatsPointer();
// If either track does not have beats, then we can't adjust the phase.
if (!otherBeats) {
return dThisPosition;
}
double dOtherLength = ControlObject::getControl(
ConfigKey(pOtherEngineBuffer->getGroup(), "track_samples"))->get();
double dOtherEnginePlayPos = pOtherEngineBuffer->getVisualPlayPos();
double dOtherPosition = dOtherLength * dOtherEnginePlayPos;
if (!BpmControl::getBeatContext(otherBeats, dOtherPosition,
NULL, NULL, NULL, &dOtherBeatFraction)) {
return dThisPosition;
}
}
bool this_near_next = dThisNextBeat - dThisPosition <= dThisPosition - dThisPrevBeat;
bool other_near_next = dOtherBeatFraction >= 0.5;
// We want our beat fraction to be identical to theirs.
// If the two tracks have similar alignment, adjust phase is straight-
// forward. Use the same fraction for both beats, starting from the previous
// beat. But if This track is nearer to the next beat and the Other track
// is nearer to the previous beat, use This Next beat as the starting point
// for the phase. (ie, we pushed the sync button late). If This track
// is nearer to the previous beat, but the Other track is nearer to the
// next beat, we pushed the sync button early so use the double-previous
// beat as the basis for the adjustment.
//
// This makes way more sense when you're actually mixing.
//
// TODO(XXX) Revisit this logic once we move away from tempo-locked,
// infinite beatgrids because the assumption that findNthBeat(-2) always
// works will be wrong then.
double dNewPlaypos = (dOtherBeatFraction + m_dUserOffset.getValue()) * dThisBeatLength;
if (this_near_next == other_near_next) {
dNewPlaypos += dThisPrevBeat;
} else if (this_near_next && !other_near_next) {
dNewPlaypos += dThisNextBeat;
} else { //!this_near_next && other_near_next
dThisPrevBeat = pBeats->findNthBeat(dThisPosition, -2);
dNewPlaypos += dThisPrevBeat;
}
if (respectLoops) {
// We might be seeking outside the loop.
const bool loop_enabled = m_pLoopEnabled->toBool();
const double loop_start_position = m_pLoopStartPosition->get();
const double loop_end_position = m_pLoopEndPosition->get();
// Cases for sanity:
//
// CASE 1
// Two identical 1-beat loops, out of phase by X samples.
// Other deck is at its loop start.
// This deck is half way through. We want to jump forward X samples to the loop end point.
//
// Two identical 1-beat loop, out of phase by X samples.
// Other deck is
// If sync target is 50% through the beat,
// If we are at the loop end point and hit sync, jump forward X samples.
// TODO(rryan): Revise this with something that keeps a broader number of
// cases in sync. This at least prevents breaking out of the loop.
if (loop_enabled &&
dThisPosition <= loop_end_position) {
const double loop_length = loop_end_position - loop_start_position;
const double end_delta = dNewPlaypos - loop_end_position;
// Syncing to after the loop end.
if (end_delta > 0 && loop_length > 0.0) {
int i = end_delta / loop_length;
dNewPlaypos = loop_start_position + end_delta - i * loop_length;
// Move new position after loop jump into phase as well.
// This is a recursive call, called only twice because of
// respectLoops = false
dNewPlaypos = getNearestPositionInPhase(dNewPlaypos, false, playing);
}
// Note: Syncing to before the loop beginning is allowed, because
// loops are catching
}
}
return dNewPlaypos;
}
bool BpmControl::syncPhase(EngineBuffer* pOtherEngineBuffer) {
if (!pOtherEngineBuffer) {
return false;
}
TrackPointer otherTrack = pOtherEngineBuffer->getLoadedTrack();
BeatsPointer otherBeats = otherTrack ? otherTrack->getBeats() : BeatsPointer();
// If either track does not have beats, then we can't adjust the phase.
if (!m_pBeats || !otherBeats) {
return false;
}
// Get the file BPM of each song.
//double dThisBpm = m_pBeats->getBpm();
//double dOtherBpm = ControlObject::getControl(
//ConfigKey(pOtherEngineBuffer->getGroup(), "file_bpm"))->get();
// Get the current position of both decks
double dThisPosition = getCurrentSample();
double dOtherLength = ControlObject::getControl(
ConfigKey(pOtherEngineBuffer->getGroup(), "track_samples"))->get();
double dOtherEnginePlayPos = ControlObject::getControl(
ConfigKey(pOtherEngineBuffer->getGroup(), "visual_playposition"))->get();
double dOtherPosition = dOtherLength * dOtherEnginePlayPos;
double dThisPrevBeat = m_pBeats->findPrevBeat(dThisPosition);
double dThisNextBeat = m_pBeats->findNextBeat(dThisPosition);
if (dThisPrevBeat == -1 || dThisNextBeat == -1 ||
dOtherEnginePlayPos == -1 || dOtherLength == 0) {
return false;
}
// Protect against the case where we are sitting exactly on the beat.
if (dThisPrevBeat == dThisNextBeat) {
dThisNextBeat = m_pBeats->findNthBeat(dThisPosition, 2);
}
double dOtherPrevBeat = otherBeats->findPrevBeat(dOtherPosition);
double dOtherNextBeat = otherBeats->findNextBeat(dOtherPosition);
if (dOtherPrevBeat == -1 || dOtherNextBeat == -1) {
return false;
}
// Protect against the case where we are sitting exactly on the beat.
if (dOtherPrevBeat == dOtherNextBeat) {
dOtherNextBeat = otherBeats->findNthBeat(dOtherPosition, 2);
}
double dThisBeatLength = fabs(dThisNextBeat - dThisPrevBeat);
double dOtherBeatLength = fabs(dOtherNextBeat - dOtherPrevBeat);
double dOtherBeatFraction = (dOtherPosition - dOtherPrevBeat) / dOtherBeatLength;
double dNewPlaypos;
bool this_near_next = dThisNextBeat - dThisPosition <= dThisPosition - dThisPrevBeat;
bool other_near_next = dOtherNextBeat - dOtherPosition <= dOtherPosition - dOtherPrevBeat;
// We want our beat fraction to be identical to theirs.
// If the two tracks have similar alignment, adjust phase is straight-
// forward. Use the same fraction for both beats, starting from the previous
// beat. But if This track is nearer to the next beat and the Other track
// is nearer to the previous beat, use This Next beat as the starting point
// for the phase. (ie, we pushed the sync button late). If This track
// is nearer to the previous beat, but the Other track is nearer to the
// next beat, we pushed the sync button early so use the double-previous
// beat as the basis for the adjustment.
//
// This makes way more sense when you're actually mixing.
//
// TODO(XXX) Revisit this logic once we move away from tempo-locked,
// infinite beatgrids because the assumption that findNthBeat(-2) always
// works will be wrong then.
if (this_near_next == other_near_next) {
dNewPlaypos = dThisPrevBeat + dOtherBeatFraction * dThisBeatLength;
} else if (this_near_next && !other_near_next) {
dNewPlaypos = dThisNextBeat + dOtherBeatFraction * dThisBeatLength;
} else { //!this_near_next && other_near_next
dThisPrevBeat = m_pBeats->findNthBeat(dThisPosition, -2);
dNewPlaypos = dThisPrevBeat + dOtherBeatFraction * dThisBeatLength;
}
// We might be seeking outside the loop.
const bool loop_enabled = m_pLoopEnabled->get() > 0.0;
const double loop_start_position = m_pLoopStartPosition->get();
const double loop_end_position = m_pLoopEndPosition->get();
// Cases for sanity:
//
// CASE 1
// Two identical 1-beat loops, out of phase by X samples.
// Other deck is at its loop start.
// This deck is half way through. We want to jump forward X samples to the loop end point.
//
// Two identical 1-beat loop, out of phase by X samples.
// Other deck is
// If sync target is 50% through the beat,
// If we are at the loop end point and hit sync, jump forward X samples.
// TODO(rryan): Revise this with something that keeps a broader number of
// cases in sync. This at least prevents breaking out of the loop.
if (loop_enabled) {
const double loop_length = loop_end_position - loop_start_position;
if (loop_length <= 0.0) {
return false;
}
// TODO(rryan): If loop_length is not a multiple of dThisBeatLength should
// we bail and not sync phase?
// Syncing to after the loop end.
double end_delta = dNewPlaypos - loop_end_position;
if (end_delta > 0) {
int i = end_delta / loop_length;
dNewPlaypos = loop_start_position + end_delta - i * loop_length;
}
// Syncing to before the loop beginning.
double start_delta = loop_start_position - dNewPlaypos;
if (start_delta > 0) {
int i = start_delta / loop_length;
dNewPlaypos = loop_end_position - start_delta + i * loop_length;
}
}
seekAbs(dNewPlaypos);
return true;
}