bool WaveTrack::Get(samplePtr buffer, sampleFormat format,
longSampleCount start, sampleCount len)
{
// Simple optimization: When this buffer is completely contained within one clip,
// don't clear anything (because we never won't have to). Otherwise, just clear
// everything to be on the safe side.
WaveClipList::Node* it;
bool doClear = true;
for (it=GetClipIterator(); it; it=it->GetNext())
{
WaveClip *clip = it->GetData();
if (start >= clip->GetStartSample() && start+len <= clip->GetEndSample())
{
doClear = false;
break;
}
}
if (doClear)
ClearSamples(buffer, format, 0, len);
for (it=GetClipIterator(); it; it=it->GetNext())
{
WaveClip *clip = it->GetData();
longSampleCount clipStart = clip->GetStartSample();
longSampleCount clipEnd = clip->GetEndSample();
if (clipEnd > start && clipStart < start+len)
{
// Clip sample region and Get/Put sample region overlap
sampleCount samplesToCopy = start+len - clipStart;
if (samplesToCopy > clip->GetNumSamples())
samplesToCopy = clip->GetNumSamples();
longSampleCount inclipDelta = 0;
longSampleCount startDelta = clipStart - start;
if (startDelta < 0)
{
inclipDelta = -startDelta; // make positive value
samplesToCopy -= inclipDelta;
startDelta = 0;
}
if (!clip->GetSamples((samplePtr)(((char*)buffer)+startDelta*SAMPLE_SIZE(format)),
format, inclipDelta, samplesToCopy))
{
wxASSERT(false); // should always work
return false;
}
}
}
return true;
}
