// construction/destruction
public samples_iterator(samples_device device)
{
m_samples = device;
m_current = -1;
}
// device_sound_interface overrides
//-------------------------------------------------
// sound_stream_update - update a sound stream
//-------------------------------------------------
public override void sound_stream_update(sound_stream stream, ListPointer <stream_sample_t> [] inputs, ListPointer <stream_sample_t> [] outputs, int samples)
{
samples_device samplesdev = (samples_device)device();
// find the channel with this stream
for (int channel = 0; channel < samplesdev.m_channels; channel++)
{
if (stream == samplesdev.m_channel[channel].stream)
{
samples_device.channel_t chan = samplesdev.m_channel[channel];
ListPointer <stream_sample_t> buffer = new ListPointer <stream_sample_t>(outputs[0]); //stream_sample_t * buffer = outputs[0];
// process if we still have a source and we're not paused
if (chan.source != null && !chan.paused)
{
// load some info locally
uint32_t pos = chan.pos;
uint32_t frac = chan.frac;
uint32_t step = chan.step;
ListBase <int16_t> sample = chan.source; //const int16_t *sample = chan.source;
uint32_t sample_length = (UInt32)chan.source_length;
while (samples-- != 0)
{
// do a linear interp on the sample
int sample1 = sample[(int)pos];
int sample2 = sample[(int)((pos + 1) % sample_length)];
int fracmult = (int)(frac >> (samples_device.FRAC_BITS - 14));
buffer[0] = ((0x4000 - fracmult) * sample1 + fracmult * sample2) >> 14; //*buffer++ = ((0x4000 - fracmult) * sample1 + fracmult * sample2) >> 14;
buffer++;
// advance
frac += step;
pos += frac >> samples_device.FRAC_BITS;
frac = frac & ((1 << samples_device.FRAC_BITS) - 1);
// handle looping/ending
if (pos >= sample_length)
{
if (chan.loop)
{
pos %= sample_length;
}
else
{
chan.source = null;
chan.source_num = -1;
if (samples > 0)
{
memset(buffer, 0, (UInt32)samples); //memset(buffer, 0, samples * sizeof(*buffer));
}
break;
}
}
}
// push position back out
chan.pos = pos;
chan.frac = frac;
}
else
{
memset(buffer, 0, (UInt32)samples); //memset(buffer, 0, samples * sizeof(*buffer));
}
break;
}
}
}
