#define RATE (44100.0)
#define NOTEMAGIC (1.059460646483)
#define TAU (2.0*PI)
#define NOTEFREQ(pitch) (pow(NOTEMAGIC, pitch) * 440.0)
#define PI (3.14159265358979323846)
#define FBO_WIDTH (4096.0)
#define EVENT_MAX (64)

#define SHRT_MAX   32767
#define BUF_WIDTH 1024


uniform int framesRendered;
 
#ifdef VERTEX
in vec2 position;	
void main()
{
	gl_Position = vec4(position, 0.0, 1.0);
}
#endif

#ifdef FRAGMENT
//layout(location=0) out vec4 out_Color;
layout(location=0) out vec4 out_Value;

float saw(float t) {
    return fract(t)*2.0-1.0;
}

float softsaw(float t, float s) {
    return mix(fract(t)*2-1, -sin(t*2.0*PI), s);
}

// Range: [-1, 1]
float rand(float t) {
    return sin(1e5*sin(t*100.));
}

float phatsaw(float t, float form) {
    float w = 0.0;
    const int COUNT = 5;
    for (int i=0;i<COUNT;i++) {
    w+= softsaw(t + sin(0.4*i)*0.2, form) * (1.0/COUNT);
    }
    return w;
}

float arp_pattern(float t) {
    //int[](0,4,9,7,2,4,7,9);
    int tones[16] = int[](0,4,9,7,2,4,7,9, -1,4,9,7,-5,4,7,9);
    float arp = 0.0;
    float at = t;
    int arpind = int(at*4) % 16;
    float arpnote = tones[arpind] + 0.31;
    arp = pow(phatsaw(t*NOTEFREQ(arpnote), 0.7 + sin(t*.2)*0.1), 3.0);
    arp *= 0.7*(0.4 + sin(arpind*3.0)*0.1)*max(0.4, -softsaw(at*6.0, 0.8));
    return arp;
}

vec2 smallsyn(float t, float f) {
    float basstime = t/8.0;
    return  0.5*
        ((1.0-fract(basstime*8.0)) 
            * (fract(basstime*12.0))
            * abs(sin(basstime*9.0*PI)))
        *vec2(softsaw(t*f*12., 0.7+.3*fract(basstime*2.0)));
}

vec2 percussion(float t) {
    float b = (t-0.20)*0.5;
    //float perc = 0.07*sin(b*2*PI*0.5) * clamp((sin(b*2*PI*8)-0.55)*40.0, 0.0, 1.0) * rand(t);
    float perc = 0.04*sin(b*2*PI*0.5) * clamp((sin(b*2*PI*8)-(1.8-t*0.013))*40.0, 0.0, 1.0) * rand(t) * clamp((t-32)*0.018, 0.0, 1.0)
;
    float tt = 20+mod(t, 30.);
    perc += 0.6 * clamp((-0.8-softsaw((b+0.6)*1.0, 0.05)), 0.0, 1.0) * sin(tt*tt*tt*1e4);

    return vec2(perc);
}

float bd(float t) {
    float tt = (1.0-min(1.0, t*0.6));
    tt *= tt * tt;
    float amp = 1.0;
    amp = clamp(tt - 0.3, 0.0, 1.0);

    float f = 40.0 + tt*50.0;
    float w = sin(2.0*PI*t*f);
    return w*0.5 *amp;
}

// thanks iq
float impulse(float k, float x)
{
    float h = k*x;
    return h*exp(1.0-h);
}

vec2 synth(float t, out vec2 out_bass)  {
	float volume = 0.4;
	vec2 wave = vec2(0.0f);//sin(t*2.0*PI*(1000.0) + chn) * volume;

    int count = 150;
    float mult = t*2.0*PI;
    float vol = 1.0/count;

    //int tones[8] = int[](0,2,4,5,7,9,10,3);
    int tones[8] = int[](0,4,9,7,2,4,7,9);

    int bass_range = 2;
    if (t > 32) {
        bass_range = 4;
    }
    float basstime = t/8.0;
    int bass_index = (int(basstime) % bass_range);
    float bassfreq = NOTEFREQ(1.0*tones[bass_index] - 12*3 + 0.2);
    //float bassenv = min(1., pow(t*0.025, 2.0)) * max(0.6, pow(1. - fract(basstime*1.0), 1.0));
    float bassenv = min(1., pow(t*0.025, 2.0))
            * min(fract(basstime)*150.0, 1.0)
            * min((1.0-fract(basstime))*100.0, 1.0)
            * max(0.6, pow(1. - fract(basstime*1.0), 1.0));

    out_bass = vec2(0.3 * bassenv * softsaw(t*bassfreq, max(0.9, 1.0-t*0.0025)));

    float soft = (1.0 + sin(t*0.1))*0.5;

    for (int i=0;i<count;i++) {
        //int add = int(t*4.0) % 5;
        //int add = int(t/2) % 4;
        //float amp = clamp((sin(t*PI*9.0 + i*20.0)-0.5)*(10.+sin(1.*i)*9.), 0.0, 1.0);
        float amp = 3.0;
        //float amp = 3.0 * max(0.3, fract(t*2.0 - i*0.001));
        //float amp = clamp((1.0-saw(i*1.0)), 0.0, 1.0);
        //float amp = 0.5f;
        int index = (i) % 8;
        int oct = (i/12) % 4;
        float note = -12*2 +  (tones[index] + oct*12) % (12*6) + sin(0.001*i)*3.0;
        float hz = NOTEFREQ(note);
        float p = 0.5 + sin(i*1.)*0.2; // ::: STEREO SOUND :::
        wave += vec2(softsaw(t*hz, soft))*vol*amp*vec2(p, 1.0-p);
    }

    //wave *= max(0.3, fract(t*2.0));

    vec2 perc = vec2(1.0, 1.0) * percussion(t) + vec2(0.2, 0.3) * percussion(t-0.1) 
        + vec2(0.2, 0.1) * percussion(t-0.18) + vec2(0.1, 0.2) * percussion(t-0.22);
    wave *= clamp(t, 0.0, 1.0);
    float synth_fadeout = clamp(1.0-(t-115)*0.04, 0.0, 1.0);
    wave *= max(0.5, synth_fadeout); // fade out 
    out_bass *= synth_fadeout;
    perc *= clamp((t-32)*0.08, 0.0, 1.0); // start fade in at 32s
    perc *= clamp(1.0-(t-110)*0.05, 0.0, 1.0); // fade out 

    vec2 audio;
    audio = wave + perc;

    vec2 arp = vec2(arp_pattern(t), arp_pattern(t-0.03)*0.8);
    arp += vec2(arp_pattern(t-0.3)*0.3, arp_pattern(t-0.6)*0.2);
    arp *= clamp((t-60)*0.1, 0.0, 1.0);

    vec2 syn = vec2(0.7, 1.0) * smallsyn(t, bassfreq)
             + vec2(0.6, 0.3) * smallsyn(t-0.05, bassfreq-0.1);
    syn += 0.1*smallsyn(t*4.0, bassfreq);
    syn *= clamp((t-122)*0.1, 0.0, 0.4);
    audio += syn;

    audio += arp;
    out_bass += vec2(bd(fract(t))) * float[](1., 0., 0., 0.5)[int(floor(t))%4]
            * clamp(1.0-(t-120)*0.1, 0.0, 1.0) * clamp((t-80)*0.1, 0.0, 1.0);
    float fadeout = clamp(1.0-(t-125)*0.035, 0.0, 1.0);
    audio *= fadeout;

    // Noise mat peak.
    audio += vec2(rand(t*.9), rand(t*.8)) * 0.04 * impulse(0.4, sqrt(10.0*max(0.0, t-96.0)));

    return audio;
}



void main(void) {
	int pos = framesRendered + (int(gl_FragCoord.x)) + (int(gl_FragCoord.y))*BUF_WIDTH;
    int tpos = pos/2;
	float t = float(pos)/RATE;
    t*=0.93; // for vaporwave
    //t += sin(t)*0.01; // LOL detune
    //int chan = pos % 2;

    vec2 bass;
    vec2 wave = synth(t, bass);
    vec2 dummy;
    vec2 reverb = vec2(0.0f);
    const int REV = 3;
    const float REV_LENGTH = 0.1f;
    for (int i=1;i<REV;i++) {
        reverb += synth(t - i*(REV_LENGTH/REV), dummy) * 0.03*(REV/i);
    }

    wave += bass;
    wave += vec2(-reverb.x, reverb.y);
    //wave = clamp(sign(wave)*sqrt(wave * sign(wave) * 1.4), -0.99, 0.99); // clamping not strictly necessary
    wave = clamp(wave * 1.4, -0.99, 0.99); // clamping not strictly necessary
	
	int left = int((wave.x)*SHRT_MAX);
    int right = int((wave.y)*SHRT_MAX);
    // STEREO SOUND
    /*
    if (chan == 1) {
        left = right;
    }*/
	out_Value = vec4(float(left & 0xFF)/256.0, ((left>>8) & 0xFF)/256.0, 
                     float(right & 0xFF)/256.0, ((right>>8) & 0xFF)/256.0);
}
#endif