static inline void YM3812UpdateOne(Chip *which, BE_ST_SndSample_T *stream, int length)
{
Bit32s buffer[OPL_NUM_OF_SAMPLES * 2];
int i;
// length should be at least the max. samplesPerMusicTick
// in Catacomb 3-D and Keen 4-6, which is param_samplerate / 700.
// So 512 is sufficient for a sample rate of 358.4 kHz.
if(length > OPL_NUM_OF_SAMPLES)
length = OPL_NUM_OF_SAMPLES;
Chip__GenerateBlock2(which, length, buffer);
// GenerateBlock2 generates a number of "length" 32-bit mono samples
// so we only need to convert them to 16-bit mono samples
for(i = 0; i < length; i++)
{
// Scale volume
Bit32s sample = 2*buffer[i];
if(sample > 16383) sample = 16383;
else if(sample < -16384) sample = -16384;
#ifdef MIXER_SAMPLE_FORMAT_FLOAT
stream[i] = (float)sample/32767.0f;
#elif (defined MIXER_SAMPLE_FORMAT_SINT16)
stream[i] = sample;
#endif
}
}
static void FillBuffer(int16_t *buffer, unsigned int nsamples)
{
unsigned int i;
// This seems like a reasonable assumption. mix_buffer is
// 1 second long, which should always be much longer than the
// SDL mix buffer.
assert(nsamples < mixing_freq);
Chip__GenerateBlock2(&opl_chip, nsamples, mix_buffer);
// Mix into the destination buffer, doubling up into stereo.
for (i=0; i<nsamples; ++i)
{
buffer[i * 2] = (int16_t) mix_buffer[i];
buffer[i * 2 + 1] = (int16_t) mix_buffer[i];
}
}
static void FillBuffer(int16_t *buffer, unsigned int nsamples)
{
unsigned int i;
// FIXME???
//assert(nsamples < opl_sample_rate);
Chip__GenerateBlock2(&opl_chip, nsamples, mix_buffer);
#ifdef STEREO
// Mix into the destination buffer, doubling up into stereo.
for (i = 0; i<nsamples; ++i)
{
buffer[i * 2] = (int16_t)mix_buffer[i];
buffer[i * 2 + 1] = (int16_t)mix_buffer[i];
}
#else
for (i = 0; i<nsamples; ++i)
{
buffer[i] = (int16_t)mix_buffer[i];
}
#endif
}
static void FillBuffer(int16_t *buffer, unsigned int nsamples)
{
unsigned int i;
int sampval;
// FIXME???
//assert(nsamples < opl_sample_rate);
Chip__GenerateBlock2(&opl_chip, nsamples, mix_buffer);
// Mix into the destination buffer, doubling up into stereo.
for (i=0; i<nsamples; ++i)
{
sampval = mix_buffer[i] * mus_opl_gain / 50;
// clip
if (sampval > 32767)
sampval = 32767;
else if (sampval < -32768)
sampval = -32768;
buffer[i * 2] = (int16_t) sampval;
buffer[i * 2 + 1] = (int16_t) sampval;
}
}