public static void tms5220_update(int ch, _ShortPtr buffer, int length)
{
short[] sample_data = new short[MAX_SAMPLE_CHUNK];
ShortSubArray curr_data = new ShortSubArray(sample_data);
short prev = last_sample, curr = curr_sample;
uint final_pos;
uint new_samples;
/* finish off the current sample */
if (source_pos > 0)
{
/* interpolate */
while (length > 0 && source_pos < FRAC_ONE)
{
buffer.write16(0, (ushort)((((int)prev * (FRAC_ONE - source_pos)) + ((int)curr * source_pos)) >> FRAC_BITS));
buffer.offset += 2;
source_pos += source_step;
length--;
}
/* if we're over, continue; otherwise, we're done */
if (source_pos >= FRAC_ONE)
source_pos -= FRAC_ONE;
else
return;
}
/* compute how many new samples we need */
final_pos = (uint)(source_pos + length * source_step);
new_samples = (final_pos + FRAC_ONE - 1) >> FRAC_BITS;
if (new_samples > MAX_SAMPLE_CHUNK)
new_samples = MAX_SAMPLE_CHUNK;
/* generate them into our buffer */
tms5220_process(sample_data, new_samples);
prev = curr;
curr = curr_data[0]; curr_data.offset++;
/* then sample-rate convert with linear interpolation */
while (length > 0)
{
/* interpolate */
while (length > 0 && source_pos < FRAC_ONE)
{
buffer.write16(0, (ushort)((((int)prev * (FRAC_ONE - source_pos)) + ((int)curr * source_pos)) >> FRAC_BITS));
source_pos += source_step;
length--;
}
/* if we're over, grab the next samples */
if (source_pos >= FRAC_ONE)
{
source_pos -= FRAC_ONE;
prev = curr;
curr = curr_data[0]; curr_data.offset++;
}
}
/* remember the last samples */
last_sample = prev;
curr_sample = curr;
}
public ShortSubArray(ShortSubArray subarray, int offset = 0)
{
this.buffer = subarray.buffer;
this.offset = subarray.offset + offset;
}
