bool AudioStreamGibberish::mix(int32_t *p_buffer, int p_frames) {
if (!active)
return false;
zeromem(p_buffer,p_frames*sizeof(int32_t));
if (!paused && active_voices==0) {
active_voices=1;
playback[0].idx=randomize();
playback[0].fp_pos=0;
playback[0].scale=Math::random(1,1+pitch_random_scale);
}
for(int i=0;i<active_voices;i++) {
RID s = _samples[playback[i].idx]->get_rid();
uint64_t fp_pos=playback[i].fp_pos;
const void *data = AudioServer::get_singleton()->sample_get_data_ptr(s);
bool is16 = AudioServer::get_singleton()->sample_get_format(s)==AudioServer::SAMPLE_FORMAT_PCM16;
int skip = AudioServer::get_singleton()->sample_is_stereo(s) ? 1: 0;
uint64_t max = AudioServer::get_singleton()->sample_get_length(s) * uint64_t(FP_LEN);
int mrate = AudioServer::get_singleton()->sample_get_mix_rate(s) * pitch_scale * playback[i].scale;
uint64_t increment = uint64_t(mrate) * uint64_t(FP_LEN) / get_mix_rate();
float vol_begin = _get_vol_at_pos(fp_pos>>FP_BITS,max>>FP_BITS,xfade_time*mrate);
float vol_end = _get_vol_at_pos((fp_pos+p_frames*increment)>>FP_BITS,max>>FP_BITS,xfade_time*mrate);
int32_t vol = CLAMP(int32_t(vol_begin * 65535),0,65535);
int32_t vol_to = CLAMP(int32_t(vol_end * 65535),0,65535);
int32_t vol_inc = (vol_to-vol)/p_frames;
bool done=false;
if (is16) {
const int16_t *smp = (int16_t*)data;
for(int i=0;i<p_frames;i++) {
if (fp_pos >= max) {
done=true;
break;
}
int idx = (fp_pos>>FP_BITS)<<skip;
p_buffer[i]+=int32_t(smp[idx])*vol;
vol+=vol_inc;
fp_pos+=increment;
}
} else {
const int8_t *smp = (int8_t*)data;
for(int i=0;i<p_frames;i++) {
if (fp_pos >= max) {
done=true;
break;
}
int idx = (fp_pos>>FP_BITS)<<skip;
p_buffer[i]+=(int32_t(smp[idx])<<8)*vol;
vol+=vol_inc;
fp_pos+=increment;
}
}
playback[i].fp_pos=fp_pos;
if (!paused && active_voices==1 && (vol_end < vol_begin || done)) {
//xfade to something else i gues
active_voices=2;
playback[1].idx=randomize();
playback[1].fp_pos=0;
playback[1].scale=Math::random(1,1+pitch_random_scale);
}
if (done) {
if (i==0 && active_voices==2) {
playback[0]=playback[1];
i--;
}
active_voices--;
}
}
double AudioDriver::get_mix_time() const {
double total = (OS::get_singleton()->get_ticks_usec() - _last_mix_time) / 1000000.0;
total += _mix_amount / (double)get_mix_rate();
return total;
}
