void
VarioSynthesiser::SetSilence()
{
mutex.lock();
UnsafeSetSilence();
mutex.unlock();
}
void
VarioSynthesiser::SetVario(unsigned sample_rate, fixed vario)
{
mutex.lock();
const int ivario = Clamp((int)(vario * 100), min_vario, max_vario);
if (dead_band_enabled && InDeadBand(ivario)) {
/* inside the "dead band" */
UnsafeSetSilence();
mutex.unlock();
return;
}
/* update the ToneSynthesiser base class */
SetTone(sample_rate, VarioToFrequency(ivario));
if (ivario > 0) {
/* while climbing, the vario sound gets interrupted by silence
periodically */
const unsigned period_ms = sample_rate
* (min_period_ms + (max_vario - ivario)
* (max_period_ms - min_period_ms) / max_vario)
/ 1000;
silence_count = period_ms / 3;
audible_count = period_ms - silence_count;
/* preserve the old "_remaining" values as much as possible, to
avoid chopping off the previous tone */
if (audible_remaining > audible_count)
audible_remaining = audible_count;
if (silence_remaining > silence_count)
silence_remaining = silence_count;
} else {
/* continuous tone while sinking */
audible_count = 1;
silence_count = 0;
}
mutex.unlock();
}
void
VarioSynthesiser::SetSilence()
{
const ScopeLock protect(mutex);
UnsafeSetSilence();
}
