/** Determine if we're changing directions (scratching) and then perform
a stretch */
CSAMPLE * EngineBufferScaleLinear::getScaled(unsigned long buf_size) {
float rate_add_new = m_dBaseRate;
float rate_add_old = m_fOldBaseRate; //Smoothly interpolate to new playback rate
int samples_read = 0;
m_samplesRead = 0;
// Guard against buf_size == 0
if ((int)buf_size == 0)
return m_buffer;
if (rate_add_new * rate_add_old < 0) {
//calculate half buffer going one way, and half buffer going
//the other way.
//first half: rate goes from old rate to zero
m_fOldBaseRate = rate_add_old;
m_dBaseRate = 0.0;
m_buffer = do_scale(m_buffer, buf_size/2, &samples_read);
// reset prev sample so we can now read in the other direction (may not
// be necessary?)
int iCurSample = static_cast<int>(ceil(m_dCurSampleIndex)) * 2;
if (iCurSample + 1 < buffer_int_size) {
int iNextSample = static_cast<int>(ceil(m_dNextSampleIndex)) * 2;
m_fPrevSample[0] = buffer_int[iNextSample];
m_fPrevSample[1] = buffer_int[iNextSample + 1];
}
// if the buffer has extra samples, do a read so RAMAN ends up back where
// it should be
int extra_samples = buffer_int_size - iCurSample - 2;
if (extra_samples > 0) {
if (extra_samples % 2 != 0)
extra_samples++;
//qDebug() << "extra samples" << extra_samples;
samples_read += m_pReadAheadManager->getNextSamples(
rate_add_new, buffer_int, extra_samples);
}
//force a buffer read:
buffer_int_size=0;
//make sure the indexes stay correct for interpolation
m_dCurSampleIndex = 0 - m_dCurSampleIndex + floor(m_dCurSampleIndex);
m_dNextSampleIndex = 1.0 - (m_dNextSampleIndex - floor(m_dNextSampleIndex));
//second half: rate goes from zero to new rate
m_fOldBaseRate = 0.0;
m_dBaseRate = rate_add_new;
//pass the address of the sample at the halfway point
do_scale(&m_buffer[buf_size/2], buf_size/2, &samples_read);
m_samplesRead = samples_read;
return m_buffer;
}
CSAMPLE* result = do_scale(m_buffer, buf_size, &samples_read);
m_samplesRead = samples_read;
return result;
}
inline void SpatialSceneBuilder::scale(double x, double y, double z)
{
do_scale(math::Vec3(x,y,z));
}
inline void SpatialSceneBuilder::scale(math::Vec3 s)
{
do_scale(s);
}
