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SFXR, C++ original

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sfxr.c
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//#include <stdio.h>
//#include <stdarg.h>
//#include <stdlib.h>
//#include <time.h>
 
#include <math.h>
#include <SDL/SDL.h>
#include <neko.h>
 
#define rnd(n) (rand()%(n+1))
#define PI 3.14159265f
 
float frnd(float range) {
return (float) rnd(10000) / 10000 * range;
}
 
bool playing_sample = false;
 
int phase;
double fperiod;
double fmaxperiod;
double fslide;
double fdslide;
int period;
float square_duty;
float square_slide;
int env_stage;
int env_time;
int env_length[3];
float env_vol;
float fphase;
float fdphase;
int iphase;
float phaser_buffer[1024];
int ipp;
float noise_buffer[32];
float fltp;
float fltdp;
float fltw;
float fltw_d;
float fltdmp;
float fltphp;
float flthp;
float flthp_d;
float vib_phase;
float vib_speed;
float vib_amp;
int rep_time;
int rep_limit;
int arp_time;
int arp_limit;
double arp_mod;
 
int wave_type;
 
float p_base_freq;
float p_freq_limit;
float p_freq_ramp;
float p_freq_dramp;
float p_duty;
float p_duty_ramp;
 
float p_vib_strength;
float p_vib_speed;
float p_vib_delay;
 
float p_env_attack;
float p_env_sustain;
float p_env_decay;
float p_env_punch;
 
bool filter_on;
float p_lpf_resonance;
float p_lpf_freq;
float p_lpf_ramp;
float p_hpf_freq;
float p_hpf_ramp;
 
float p_pha_offset;
float p_pha_ramp;
 
float p_repeat_speed;
 
float p_arp_speed;
float p_arp_mod;
 
float master_vol = 0.05f;
float sound_vol = 0.5f;
 
int wav_bits = 16;
int wav_freq = 44100;
 
int file_sampleswritten;
float filesample = 0.0f;
int fileacc = 0;
 
void resetParams() {
wave_type = 0;
p_base_freq = 0.3f;
p_freq_limit = 0.0f;
p_freq_ramp = 0.0f;
p_freq_dramp = 0.0f;
p_duty = 0.0f;
p_duty_ramp = 0.0f;
p_vib_strength = 0.0f;
p_vib_speed = 0.0f;
p_vib_delay = 0.0f;
p_env_attack = 0.0f;
p_env_sustain = 0.3f;
p_env_decay = 0.4f;
p_env_punch = 0.0f;
filter_on = false;
p_lpf_resonance = 0.0f;
p_lpf_freq = 1.0f;
p_lpf_ramp = 0.0f;
p_hpf_freq = 0.0f;
p_hpf_ramp = 0.0f;
p_pha_offset = 0.0f;
p_pha_ramp = 0.0f;
p_repeat_speed = 0.0f;
p_arp_speed = 0.0f;
p_arp_mod = 0.0f;
}
 
void resetSample(bool restart) {
if (!restart)
phase = 0;
fperiod = 100.0 / (p_base_freq * p_base_freq + 0.001);
period = (int) fperiod;
fmaxperiod = 100.0 / (p_freq_limit * p_freq_limit + 0.001);
fslide = 1.0 - pow((double) p_freq_ramp, 3.0) * 0.01;
fdslide = -pow((double) p_freq_dramp, 3.0) * 0.000001;
square_duty = 0.5f - p_duty * 0.5f;
square_slide = -p_duty_ramp * 0.00005f;
if (p_arp_mod >= 0.0f)
arp_mod = 1.0 - pow((double) p_arp_mod, 2.0) * 0.9;
else
arp_mod = 1.0 + pow((double) p_arp_mod, 2.0) * 10.0;
arp_time = 0;
arp_limit = (int) (pow(1.0f - p_arp_speed, 2.0f) * 20000 + 32);
if (p_arp_speed == 1.0f)
arp_limit = 0;
if (!restart) {
// reset filter
fltp = 0.0f;
fltdp = 0.0f;
fltw = pow(p_lpf_freq, 3.0f) * 0.1f;
fltw_d = 1.0f + p_lpf_ramp * 0.0001f;
fltdmp = 5.0f / (1.0f + pow(p_lpf_resonance, 2.0f) * 20.0f)
* (0.01f + fltw);
if (fltdmp > 0.8f)
fltdmp = 0.8f;
fltphp = 0.0f;
flthp = pow(p_hpf_freq, 2.0f) * 0.1f;
flthp_d = 1.0 + p_hpf_ramp * 0.0003f;
// reset vibrato
vib_phase = 0.0f;
vib_speed = pow(p_vib_speed, 2.0f) * 0.01f;
vib_amp = p_vib_strength * 0.5f;
// reset envelope
env_vol = 0.0f;
env_stage = 0;
env_time = 0;
env_length[0] = (int) (p_env_attack * p_env_attack * 100000.0f);
env_length[1] = (int) (p_env_sustain * p_env_sustain * 100000.0f);
env_length[2] = (int) (p_env_decay * p_env_decay * 100000.0f);
fphase = pow(p_pha_offset, 2.0f) * 1020.0f;
if (p_pha_offset < 0.0f)
fphase = -fphase;
fdphase = pow(p_pha_ramp, 2.0f) * 1.0f;
if (p_pha_ramp < 0.0f)
fdphase = -fdphase;
iphase = abs((int) fphase);
//int i;
for (int i = 0; i < 1024; i++)
phaser_buffer[i] = 0.0f;
for (int i = 0; i < 32; i++)
noise_buffer[i] = frnd(2.0f) - 1.0f;
rep_time = 0;
rep_limit = (int) (pow(1.0f - p_repeat_speed, 2.0f) * 20000 + 32);
if (p_repeat_speed == 0.0f)
rep_limit = 0;
}
}
 
/*
void playSample() {
resetSample( false );
playing_sample = true;
printf("PLAYEDSAMPLE\n");
}
*/
 
static inline void synthSample(int length, float* buffer, FILE* file) {
for (int i = 0; i < length; i++) {
if (!playing_sample)
break;
rep_time++;
if (rep_limit != 0 && rep_time >= rep_limit) {
rep_time = 0;
resetSample(true);
}
// frequency envelopes/arpeggios
arp_time++;
if (arp_limit != 0 && arp_time >= arp_limit) {
arp_limit = 0;
fperiod *= arp_mod;
}
fslide += fdslide;
fperiod *= fslide;
if (fperiod > fmaxperiod) {
fperiod = fmaxperiod;
if (p_freq_limit > 0.0f)
playing_sample = false;
}
float rfperiod = fperiod;
if (vib_amp > 0.0f) {
vib_phase += vib_speed;
rfperiod = fperiod * (1.0 + sin(vib_phase) * vib_amp);
}
period = (int) rfperiod;
if (period < 8)
period = 8;
square_duty += square_slide;
if (square_duty < 0.0f)
square_duty = 0.0f;
if (square_duty > 0.5f)
square_duty = 0.5f;
// volume envelope
env_time++;
if (env_time > env_length[env_stage]) {
env_time = 0;
env_stage++;
if (env_stage == 3)
playing_sample = false;
}
if (env_stage == 0)
env_vol = (float) env_time / env_length[0];
if (env_stage == 1)
env_vol = 1.0f
+ pow(1.0f - (float) env_time / env_length[1], 1.0f) * 2.0f
* p_env_punch;
if (env_stage == 2)
env_vol = 1.0f - (float) env_time / env_length[2];
 
// phaser step
fphase += fdphase;
iphase = abs((int) fphase);
if (iphase > 1023)
iphase = 1023;
 
if (flthp_d != 0.0f) {
flthp *= flthp_d;
if (flthp < 0.00001f)
flthp = 0.00001f;
if (flthp > 0.1f)
flthp = 0.1f;
}
 
float ssample = 0.0f;
int si = 0;
for (; si < 8; si++) // 8x supersampling
{
float sample = 0.0f;
phase++;
if (phase >= period) {
// phase=0;
phase %= period;
if (wave_type == 3) {
int i = 0;
for (; i < 32; i++)
noise_buffer[i] = frnd(2.0f) - 1.0f;
}
}
// base waveform
float fp = (float) phase / period;
switch (wave_type) {
case 0: // square
if (fp < square_duty)
sample = 0.5f;
else
sample = -0.5f;
break;
case 1: // sawtooth
sample = 1.0f - fp * 2;
break;
case 2: // sine
sample = (float) sin(fp * 2 * PI);
break;
case 3: // noise
sample = noise_buffer[phase * 32 / period];
break;
}
// lp filter
float pp = fltp;
fltw *= fltw_d;
if (fltw < 0.0f)
fltw = 0.0f;
if (fltw > 0.1f)
fltw = 0.1f;
if (p_lpf_freq != 1.0f) {
fltdp += (sample - fltp) * fltw;
fltdp -= fltdp * fltdmp;
} else {
fltp = sample;
fltdp = 0.0f;
}
fltp += fltdp;
// hp filter
fltphp += fltp - pp;
fltphp -= fltphp * flthp;
sample = fltphp;
// phaser
phaser_buffer[ipp & 1023] = sample;
sample += phaser_buffer[(ipp - iphase + 1024) & 1023];
ipp = (ipp + 1) & 1023;
// final accumulation and envelope application
ssample += sample * env_vol;
}
ssample = ssample / 8 * master_vol;
ssample *= 2.0f * sound_vol;
if (buffer != NULL) {
if (ssample > 1.0f)
ssample = 1.0f;
if (ssample < -1.0f)
ssample = -1.0f;
*buffer++ = ssample;
}
if (file != NULL) {
// quantize depending on format
// accumulate/count to accomodate variable sample rate?
ssample *= 4.0f; // arbitrary gain to get reasonable output volume...
if (ssample > 1.0f)
ssample = 1.0f;
if (ssample < -1.0f)
ssample = -1.0f;
filesample += ssample;
fileacc++;
if (wav_freq == 44100 || fileacc == 2) {
filesample /= fileacc;
fileacc = 0;
if (wav_bits == 16) {
short isample = (short) (filesample * 32000);
fwrite(&isample, 1, 2, file);
} else {
unsigned char isample = (unsigned char) (filesample * 127
+ 128);
fwrite(&isample, 1, 1, file);
}
filesample = 0.0f;
}
file_sampleswritten++;
}
}
}
 
bool mute_stream;
 
static void audioCallback(void *userdata, Uint8 *stream, int len) {
//printf("audioCallback\n");
if (playing_sample && !mute_stream) {
unsigned int l = len / 2;
float fbuf[l];
memset(fbuf, 0, sizeof(fbuf));
synthSample(l, fbuf, NULL);
while (l--) {
float f = fbuf[l];
if (f < -1.0)
f = -1.0;
if (f > 1.0)
f = 1.0;
((Sint16*) stream)[l] = (Sint16)(f * 32767);
}
} else
memset(stream, 0, len);
}
 
////////////////////////////////////////////////////////////////////
 
static value sfxr_init() {
 
printf( "sfxr_initsfxr_initsfxr_init\n" );
 
SDL_AudioSpec des;
des.freq = 44100;
des.format = AUDIO_S16SYS;
des.channels = 1;
//des.samples = 512;
des.samples = 4096; //8192;
des.callback = audioCallback;
des.userdata = NULL;
//VERIFY( !SDL_OpenAudio( &des, NULL ) );
//printf( "%i\n", !SDL_OpenAudio( &des, NULL ) );
if (SDL_OpenAudio(&des, NULL) < 0)
return val_false;
SDL_PauseAudio(0);
/*
// pickup/coin
resetParams();
p_base_freq=0.4f+frnd(0.5f);
p_env_attack=0.0f;
p_env_sustain=frnd(0.1f);
p_env_decay=0.1f+frnd(0.4f);
p_env_punch=0.3f+frnd(0.3f);
if(rnd(1)) {
p_arp_speed=0.5f+frnd(0.2f);
p_arp_mod=0.2f+frnd(0.4f);
}
*/
 
printf( "SoundFX engine initialized\n" );
//#ifdef FNORD_DEBUG
//#endif
return val_true;
}
 
static value sfxr_set(value i) {
switch (val_int(i)) {
case 0: // pickup/coin
resetParams();
p_base_freq = 0.4f + frnd(0.5f);
p_env_attack = 0.0f;
p_env_sustain = frnd(0.1f);
p_env_decay = 0.1f + frnd(0.4f);
p_env_punch = 0.3f + frnd(0.3f);
if (rnd(1)) {
p_arp_speed = 0.5f + frnd(0.2f);
p_arp_mod = 0.2f + frnd(0.4f);
}
break;
case 1:
/////
break;
}
}
 
static value sfxr_play() {
//playSample();
resetSample(false);
playing_sample = true;
printf("PLAYEDSAMPLE\n");
return val_null;
}
 
static value sfxr_stop() {
//TODO
return val_null;
}
 
DEFINE_PRIM( sfxr_init, 0 );
DEFINE_PRIM( sfxr_set, 1 );
DEFINE_PRIM( sfxr_play, 0 );
DEFINE_PRIM( sfxr_stop, 0 );

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