GLSL Sound 02

sound_trance.glsl

#define PI acos(-1.0)

struct Note
{
  float freq;
};

Note GetNote(int index)
{
  Note n;
  n.freq = 440.0 * exp2(float(index)/12.0);
  return n;
}

float SawWave(float time, float freq)
{
  return fract(time * freq);
}

float SineWave(float time, float freq)
{
  return sin(time * freq * 2.0 * PI);
}

float KickWave(float time, float freq)
{
  // float s = SineWave(time, freq);
  float s = smoothstep(0.0, 0.1, fract(time * freq));
  // float th = 0.2;
  // s = s / th;
  // s = clamp(s, -1.0, 1.0);
  return s;
  // return SineWave(time, freq);
}


float SuperSawWave(float time, float freq)
{
  float wave;
  float vol = 1.0;
  int n = 10;
  for (int i = 0; i < n; i++)
  {
    float saw = SawWave(time, freq);
    saw = pow(saw, 4.0);
    // wave += SawWave(time, freq) * vol;
    wave += saw * vol;
    time += 0.1;
    freq *= 1.007;
    vol *= 0.73;
  }
  wave /= 8.0;
  return wave;
}


float Wave(float time, float freq)
{
  float wave;
  float vol = 1.0;
  // freq *= 1.0 + 0.05 * SineWave(time, 1.0);
  
  for (int i = 0; i < 7; i++)
  {
    wave += SawWave(time, freq) * vol;
    time += 0.1;
    freq *= 1.007;
    vol *= 0.73;
  }
  wave /= 7.0;
  return wave;
}


float HighHat(float time)
{
  // if (time <= 0.5) return 0.0;
  
  time += 0.5;
  float amp = fract(-time*2.);
  amp = pow(amp, 16.0);
  return (fract(sin(time*1e3)*1e6)-.5) * amp;
}

float SquareWave(float time, float freq, float rate)
{
  return step(fract(time * freq), rate);
}

float TriangleWave(float time, float freq, float a)
{
  float t = fract(time*freq);
  return min(t / a, (1.0-t)/(1.0 - a));
}

float SuperSquareWave(float time, float freq, float rate)
{
  float wave;
  float vol = 1.0;
  int n = 10;
  for (int i = 0; i < n; i++)
  {
    float saw = SquareWave(time, freq, rate);
    saw = pow(saw, 4.0);
    // wave += SawWave(time, freq) * vol;
    wave += saw * vol;
    time += 0.1;
    freq *= 1.007;
    vol *= 0.73;
  }
  wave /= 8.0;
  return wave;
}

float Wave1(float time)
{
  float tempo = 0.5;
  int noteCount = 4;
  float waveTime = time;
  
  time *= tempo;
  
  //float amp = exp(-3.0 * fract(time));
  
  int noteIndex = int(time / 2.0);
  noteIndex = noteIndex % noteCount;
  
  int key = -8-12;
  Note[] notes1 = Note[]
  (
    GetNote(0),
    GetNote(-2+12),
    GetNote(-4),
    GetNote(-7)
  );
  Note[] notes2 = Note[]
  (
    GetNote(3),
    GetNote(0),
    GetNote(-2+12),
    GetNote(-2)
  );
  Note[] notes3 = Note[]
  (
    GetNote(5),
    GetNote(3),
    GetNote(3),
    GetNote(0+12)
  );
  
  Note n1 = notes1[noteIndex];
  Note n2 = notes2[noteIndex];
  Note n3 = notes3[noteIndex];
  int ampIndex = int(fract(time)) % 4;
  
  #define PLUCK pow(1.0 - fract(time * 8.0), 0.7)
  float amp = 
      pow(fract(mod(-time* 16., 8.)/3.), 0.3)
      * mix(0.1, 1.0, PLUCK);
  float freqRange = 4.0;
  float wave =  
    SuperSawWave(waveTime, (n1.freq) * exp2(float(key)/12.0)) +
    SuperSawWave(waveTime, (n2.freq) * exp2(float(key)/12.0)) +
    SuperSawWave(waveTime, (n3.freq) * exp2(float(key)/12.0)) 
  ;
  return wave * amp;
}

float Wave2(float time)
{
  float tempo = 0.5;
  int noteCount = 4;
  float waveTime = time;
  
  time *= tempo;
  
  //float amp = exp(-3.0 * fract(time));
  
  int noteIndex = int(time*16.0);
  
  int key = -8-24;
  Note[] notes1 = Note[]
  (
    GetNote(0),
    GetNote(5),
    GetNote(8),
    GetNote(10)
  );
  
  key += (noteIndex / 4 % 8) * 12;
  
  Note n1 = notes1[noteIndex % noteCount];
  int ampIndex = int(fract(time)) % 4;
  
  #define PLUCK pow(1.0 - fract(time * 8.0), 0.7)
  float amp = 
      pow(fract(mod(-time* 16., 8.)/3.), 0.3)
      * mix(0.1, 1.0, PLUCK)
      // * exp(-6.0*float(noteIndex % noteCount) / float(noteCount))
      ;
  float freqRange = 4.0;
  float s = 
    SineWave(waveTime, (n1.freq) * exp2(float(key)/12.0)) + 
    SineWave(waveTime, (n1.freq * 1.03 + 10.05) * exp2(float(key)/12.0)) * 0.1
    ;
    
  float th = 0.1;
  s = s / th;
  s = clamp(s, -1., 1.);
  float wave = s;
  return wave * amp;
}

float BaseWave(float time, float freq)
{
  float wave;
  wave += SquareWave(time, freq, 0.2);
  wave += SquareWave(time, freq * 2.0, 0.2) * 0.5;
  wave += SquareWave(time, freq * 4.0, 0.2) * 0.15;
  return wave / 2.0;
}

float Wave3(float time)
{
  time -= 1.0 / 4.0;
  float wave = BaseWave(time, 440.0*exp2(-4.0));
  float amp = SquareWave(time - 0.5, 2.0, 0.5);
  return wave * 0.1 * amp;
}

float Wave4(float time)
{
  int noteCount = 64;
  float tempo = 2.0 ;
  int key = -8-12;
  Note[] notes = Note[]
  (
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(0),
    GetNote(0),
    
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(0),
    GetNote(-2),
    
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    GetNote(0),
    
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(3),
    GetNote(0),
    GetNote(0),
    
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1),
    GetNote(1)
  );
  int index = int(time * tempo) % noteCount;

  float freq = notes[index].freq * exp2(float(key)/12.0) + SineWave(time, .0);
  
  float wave;
  float a = 0.5;
  float amp = 1.0 - fract(time);
  
  wave += SuperSquareWave(time, freq * 1.0, a) / 4.0;
  wave += SuperSquareWave(time, freq * 2.0, a) / 2.0;
  wave += SuperSquareWave(time, freq * 3.0, a);
  
  // wave /= 3.0;
  
  return wave * 0.2;
}

vec2 mainSound(float time){
  time = time * 1.2;
  time = mod(time, 64.0);
  float waveTime = time;
  
  float kickVolume = pow(fract(-time*2.),4.);
  // float kick = 3.0*sin(60.0 * PI *waveTime) * kickVolume * 0.8;
  float kick = KickWave(waveTime, 30.0) * kickVolume * 0.5;
  kickVolume = pow(kickVolume, 4.0);


  float hat = HighHat(time);
  // delay
  float delay = 0.12;
  float wave1; // トランスっぽい和音が入る
  float sum;
  {
    for (int i = 5; i >= 1; i--)
    {
      wave1 += Wave1(waveTime - delay * float(i));
      wave1 *= 0.7;
      sum += 0.7;
    }
    wave1 *= 0.5;
    wave1 += Wave1(waveTime);
    wave1 = wave1 / sum * 2.0;
    wave1 = mix(wave1, kick, kickVolume);
    wave1 += hat * 0.1;
  }
  
  float wave2; // ピコピコなってるアルペジオが入る
  float wave3 = Wave3(time); // ベースが入る
  float wave4; // メロディが入る
  if (time > 32.0)
  {
    // フェードイン
    float amp = time - 32.0;
    time /= 16.0; 
    amp = min(amp, 1.0); 
    amp = pow(amp, 0.1); 
    amp = mix(0.2, 1.0, amp);
    
    for (int i = 5; i >= 1; i--)
    {
      wave4 += Wave4(waveTime - delay * float(i));
      wave4 *= 0.5;
    }
    wave4 *= 0.3;
    wave4 += Wave4(waveTime);
    wave4 *= amp;
  }
  // else
  {
    wave2 += Wave2(waveTime);
  }
  
  float wave = wave1 + wave2 * 0.02 + wave3 * 1.0 + wave4;
  return vec2(wave * 1.0);
}