sfxr2wav.c

// -----------------------------
// sfxr - sound effect generator
// -----------------------------
//    by DrPetter, 2007-12-14
//     developed for LD48#10
// -----------------------------
//
// License:
// Basically, I don't care what you do with it, anything goes.
// To please all the troublesome folks who request a formal license,
// I attach the "MIT license".


#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include <stdbool.h>

#define rnd(n) (rand()%(n+1))

#define PI 3.14159265f

float frnd(float range)
{
    return (float)rnd(10000)/10000*range;
}

typedef struct Category
{
    char name[32];
} Category;

Category categories[10];

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;


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;

float* vselected=NULL;
int vcurbutton=-1;

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;
}

bool LoadSettings(const char* filename)
{
    FILE* file=fopen(filename, "rb");
    if(!file)
        return false;

    int version=0;
    fread(&version, 1, sizeof(int), file);
    if(version!=100 && version!=101 && version!=102)
        return false;

    fread(&wave_type, 1, sizeof(int), file);

    sound_vol=0.5f;
    if(version==102)
        fread(&sound_vol, 1, sizeof(float), file);

    fread(&p_base_freq, 1, sizeof(float), file);
    fread(&p_freq_limit, 1, sizeof(float), file);
    fread(&p_freq_ramp, 1, sizeof(float), file);
    if(version>=101)
        fread(&p_freq_dramp, 1, sizeof(float), file);
    fread(&p_duty, 1, sizeof(float), file);
    fread(&p_duty_ramp, 1, sizeof(float), file);

    fread(&p_vib_strength, 1, sizeof(float), file);
    fread(&p_vib_speed, 1, sizeof(float), file);
    fread(&p_vib_delay, 1, sizeof(float), file);

    fread(&p_env_attack, 1, sizeof(float), file);
    fread(&p_env_sustain, 1, sizeof(float), file);
    fread(&p_env_decay, 1, sizeof(float), file);
    fread(&p_env_punch, 1, sizeof(float), file);

    fread(&filter_on, 1, sizeof(bool), file);
    fread(&p_lpf_resonance, 1, sizeof(float), file);
    fread(&p_lpf_freq, 1, sizeof(float), file);
    fread(&p_lpf_ramp, 1, sizeof(float), file);
    fread(&p_hpf_freq, 1, sizeof(float), file);
    fread(&p_hpf_ramp, 1, sizeof(float), file);

    fread(&p_pha_offset, 1, sizeof(float), file);
    fread(&p_pha_ramp, 1, sizeof(float), file);

    fread(&p_repeat_speed, 1, sizeof(float), file);

    if(version>=101)
    {
        fread(&p_arp_speed, 1, sizeof(float), file);
        fread(&p_arp_mod, 1, sizeof(float), file);
    }

    fclose(file);
    return true;
}

bool SaveSettings(const char* filename)
{
    FILE* file=fopen(filename, "wb");
    if(!file)
        return false;

    int version=102;
    fwrite(&version, 1, sizeof(int), file);

    fwrite(&wave_type, 1, sizeof(int), file);

    fwrite(&sound_vol, 1, sizeof(float), file);

    fwrite(&p_base_freq, 1, sizeof(float), file);
    fwrite(&p_freq_limit, 1, sizeof(float), file);
    fwrite(&p_freq_ramp, 1, sizeof(float), file);
    fwrite(&p_freq_dramp, 1, sizeof(float), file);
    fwrite(&p_duty, 1, sizeof(float), file);
    fwrite(&p_duty_ramp, 1, sizeof(float), file);

    fwrite(&p_vib_strength, 1, sizeof(float), file);
    fwrite(&p_vib_speed, 1, sizeof(float), file);
    fwrite(&p_vib_delay, 1, sizeof(float), file);

    fwrite(&p_env_attack, 1, sizeof(float), file);
    fwrite(&p_env_sustain, 1, sizeof(float), file);
    fwrite(&p_env_decay, 1, sizeof(float), file);
    fwrite(&p_env_punch, 1, sizeof(float), file);

    fwrite(&filter_on, 1, sizeof(bool), file);
    fwrite(&p_lpf_resonance, 1, sizeof(float), file);
    fwrite(&p_lpf_freq, 1, sizeof(float), file);
    fwrite(&p_lpf_ramp, 1, sizeof(float), file);
    fwrite(&p_hpf_freq, 1, sizeof(float), file);
    fwrite(&p_hpf_ramp, 1, sizeof(float), file);

    fwrite(&p_pha_offset, 1, sizeof(float), file);
    fwrite(&p_pha_ramp, 1, sizeof(float), file);

    fwrite(&p_repeat_speed, 1, sizeof(float), file);

    fwrite(&p_arp_speed, 1, sizeof(float), file);
    fwrite(&p_arp_mod, 1, sizeof(float), file);

    fclose(file);
    return true;
}

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);
        ipp=0;
        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 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;
        for(int si=0;si<8;si++) // 8x supersampling
        {
            float sample=0.0f;
            phase++;
            if(phase>=period)
            {
//              phase=0;
                phase%=period;
                if(wave_type==3)
                    for(int i=0;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++;
        }
    }
}

void PlaySample()
{
    ResetSample(false);
    playing_sample=true;
}


bool ExportWAV(char* filename)
{
    FILE* foutput=fopen(filename, "wb");
    if(!foutput)
        return false;
    // write wav header
    char string[32];
    unsigned int dword=0;
    unsigned short word=0;
    fwrite("RIFF", 4, 1, foutput); // "RIFF"
    dword=0;
    fwrite(&dword, 1, 4, foutput); // remaining file size
    fwrite("WAVE", 4, 1, foutput); // "WAVE"

    fwrite("fmt ", 4, 1, foutput); // "fmt "
    dword=16;
    fwrite(&dword, 1, 4, foutput); // chunk size
    word=1;
    fwrite(&word, 1, 2, foutput); // compression code
    word=1;
    fwrite(&word, 1, 2, foutput); // channels
    dword=wav_freq;
    fwrite(&dword, 1, 4, foutput); // sample rate
    dword=wav_freq*wav_bits/8;
    fwrite(&dword, 1, 4, foutput); // bytes/sec
    word=wav_bits/8;
    fwrite(&word, 1, 2, foutput); // block align
    word=wav_bits;
    fwrite(&word, 1, 2, foutput); // bits per sample

    fwrite("data", 4, 1, foutput); // "data"
    dword=0;
    int foutstream_datasize=ftell(foutput);
    fwrite(&dword, 1, 4, foutput); // chunk size

    // write sample data
    file_sampleswritten=0;
    filesample=0.0f;
    fileacc=0;
    PlaySample();
    while(playing_sample)
        SynthSample(256, NULL, foutput);

    // seek back to header and write size info
    fseek(foutput, 4, SEEK_SET);
    dword=0;
    dword=foutstream_datasize-4+file_sampleswritten*wav_bits/8;
    fwrite(&dword, 1, 4, foutput); // remaining file size
    fseek(foutput, foutstream_datasize, SEEK_SET);
    dword=file_sampleswritten*wav_bits/8;
    fwrite(&dword, 1, 4, foutput); // chunk size (data)
    fclose(foutput);

    return true;
}





bool loadPreset(int aPresetNo, int aRandSeed)
{
    if (aPresetNo < 0 || aPresetNo > 6)
        return false; //INVALID_PARAMETER;

    ResetParams();
    srand(aRandSeed);
    switch(aPresetNo)
    {
    case 0: // pickup/coin
        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: // laser/shoot
        wave_type=rnd(2);
        if(wave_type==2 && rnd(1))
            wave_type=rnd(1);
        p_base_freq=0.5f+frnd(0.5f);
        p_freq_limit=p_base_freq-0.2f-frnd(0.6f);
        if(p_freq_limit<0.2f) p_freq_limit=0.2f;
        p_freq_ramp=-0.15f-frnd(0.2f);
        if(rnd(2)==0)
        {
            p_base_freq=0.3f+frnd(0.6f);
            p_freq_limit=frnd(0.1f);
            p_freq_ramp=-0.35f-frnd(0.3f);
        }
        if(rnd(1))
        {
            p_duty=frnd(0.5f);
            p_duty_ramp=frnd(0.2f);
        }
        else
        {
            p_duty=0.4f+frnd(0.5f);
            p_duty_ramp=-frnd(0.7f);
        }
        p_env_attack=0.0f;
        p_env_sustain=0.1f+frnd(0.2f);
        p_env_decay=frnd(0.4f);
        if(rnd(1))
            p_env_punch=frnd(0.3f);
        if(rnd(2)==0)
        {
            p_pha_offset=frnd(0.2f);
            p_pha_ramp=-frnd(0.2f);
        }
        if(rnd(1))
            p_hpf_freq=frnd(0.3f);
        break;
    case 2: // explosion
        wave_type=3;
        if(rnd(1))
        {
            p_base_freq=0.1f+frnd(0.4f);
            p_freq_ramp=-0.1f+frnd(0.4f);
        }
        else
        {
            p_base_freq=0.2f+frnd(0.7f);
            p_freq_ramp=-0.2f-frnd(0.2f);
        }
        p_base_freq*=p_base_freq;
        if(rnd(4)==0)
            p_freq_ramp=0.0f;
        if(rnd(2)==0)
            p_repeat_speed=0.3f+frnd(0.5f);
        p_env_attack=0.0f;
        p_env_sustain=0.1f+frnd(0.3f);
        p_env_decay=frnd(0.5f);
        if(rnd(1)==0)
        {
            p_pha_offset=-0.3f+frnd(0.9f);
            p_pha_ramp=-frnd(0.3f);
        }
        p_env_punch=0.2f+frnd(0.6f);
        if(rnd(1))
        {
            p_vib_strength=frnd(0.7f);
            p_vib_speed=frnd(0.6f);
        }
        if(rnd(2)==0)
        {
            p_arp_speed=0.6f+frnd(0.3f);
            p_arp_mod=0.8f-frnd(1.6f);
        }
        break;
    case 3: // powerup
        if(rnd(1))
            wave_type=1;
        else
            p_duty=frnd(0.6f);
        if(rnd(1))
        {
            p_base_freq=0.2f+frnd(0.3f);
            p_freq_ramp=0.1f+frnd(0.4f);
            p_repeat_speed=0.4f+frnd(0.4f);
        }
        else
        {
            p_base_freq=0.2f+frnd(0.3f);
            p_freq_ramp=0.05f+frnd(0.2f);
            if(rnd(1))
            {
                p_vib_strength=frnd(0.7f);
                p_vib_speed=frnd(0.6f);
            }
        }
        p_env_attack=0.0f;
        p_env_sustain=frnd(0.4f);
        p_env_decay=0.1f+frnd(0.4f);
        break;
    case 4: // hit/hurt
        wave_type=rnd(2);
        if(wave_type==2)
            wave_type=3;
        if(wave_type==0)
            p_duty=frnd(0.6f);
        p_base_freq=0.2f+frnd(0.6f);
        p_freq_ramp=-0.3f-frnd(0.4f);
        p_env_attack=0.0f;
        p_env_sustain=frnd(0.1f);
        p_env_decay=0.1f+frnd(0.2f);
        if(rnd(1))
            p_hpf_freq=frnd(0.3f);
        break;
    case 5: // jump
        wave_type=0;
        p_duty=frnd(0.6f);
        p_base_freq=0.3f+frnd(0.3f);
        p_freq_ramp=0.1f+frnd(0.2f);
        p_env_attack=0.0f;
        p_env_sustain=0.1f+frnd(0.3f);
        p_env_decay=0.1f+frnd(0.2f);
        if(rnd(1))
            p_hpf_freq=frnd(0.3f);
        if(rnd(1))
            p_lpf_freq=1.0f-frnd(0.6f);
        break;
    case 6: // blip/select
        wave_type=rnd(1);
        if(wave_type==0)
            p_duty=frnd(0.6f);
        p_base_freq=0.2f+frnd(0.4f);
        p_env_attack=0.0f;
        p_env_sustain=0.1f+frnd(0.1f);
        p_env_decay=frnd(0.2f);
        p_hpf_freq=0.1f;
        break;
    }
    return true;
}

int main(int argc, char **argv) {
    if( argc != 3 ) exit( -printf("%s input.sfxr output.wav\n", argv[0]) );
    if( argc > 1 && LoadSettings(argv[1]) ) {
        if( argc > 2 && ExportWAV(argv[2]) ) {
            return 0;
        } else {
            fprintf(stderr, "Cannot open file %s for writing\n", argv[2]);
        }
    } else {
        fprintf(stderr, "Cannot open file %s for reading\n", argv[1]);
    }
    return -1;
}