GPU Sound Demo (WGL2)

A demo showcasing the usage of the fftTexture sampler2D uniform, this time using PRGM8 (dedicated exclusively to WebGL2 GPU-generated sound).

Created by marcogomez on Mon, 11 Oct 2021 09:48:08 GMT.

Author Twitter Profile: TheCodeTherapy

fft, texture, audio, fast fourier transform, visualizer, integer, hash


#version 300 es
// ╔═════════════╦════════════════╗
// ║ Marco Gomez ║ https://mgz.me ║
// ╚═════════════╩════════════════╝
precision highp float;

uniform sampler2D prgm3Texture;
uniform vec2 resolution;
uniform float time;

out vec4 fragColor;

void main(void) {
  vec2 uv = gl_FragCoord.xy / resolution.xy;
  vec4 prgm3 = texture(prgm3Texture, uv);
  fragColor = prgm3;
}


#version 300 es
// ╔═════════════╦════════════════╗
// ║ Marco Gomez ║ https://mgz.me ║
// ╚═════════════╩════════════════╝
precision highp float;

uniform sampler2D fftTexture;
uniform vec2 resolution;
uniform float time;
uniform int frame;

out vec4 fragColor;

vec3 hash33(vec3 p3) {
  p3 = fract(p3 * vec3(0.1031, 0.1030, 0.0973));
  p3 += dot(p3, p3.yxz + 19.19);
  return fract((p3.xxy + p3.yxx) * p3.zyx);
}

vec3 mixColor(vec3 col1, vec3 col2, float v) {
  v = clamp(v, 0.0, 1.0);
  return clamp(col1 + v * (col2 - col1 * 1.5), 0.0, 1.0);
}

void main(void) {
  vec2 uv = gl_FragCoord.xy / resolution.xy;
  uv.x = (uv.x - 0.5 > 0.0) ? uv.x - 0.521 : 0.479 - uv.x;
  vec2 p = uv * 2.0 - 1.0;
  p *= vec2(resolution.x / resolution.y, 1.0);
  p.y += 0.3;
  vec3 col = vec3(0.0);
  vec3 ref = vec3(0.0);
  float nBands = 64.0;
  float i = floor((uv.x * 1.3 + 0.3) * nBands);
  float f = fract((uv.x * 1.3 + 0.3) * nBands);
  float band = i/nBands;
  band *= band * band;
  band = band * 0.995;
  band += 0.005;
  float s = texture(fftTexture, vec2(band, 0.25)).x;
  const int nColors = 4;
  vec3 colors[nColors];
  colors[0] = vec3(0.0, 0.0, 1.0);
  colors[1] = vec3(0.0, 1.0, 1.0);
  colors[2] = vec3(1.0, 1.0, 0.0);
  colors[3] = vec3(1.0, 0.0, 0.0);
  vec3 gradCol = colors[0];
  float n = float(nColors) - 1.0;
  for(int i = 1; i < nColors; i++) {
    gradCol = mixColor(gradCol, colors[i], (s - float(i - 1) / n) * n);
  }
  col += vec3(1.0 - smoothstep(0.0, 0.001, p.y - s * 1.25));
  col *= gradCol;
  ref += vec3(1.0 - smoothstep(0.0, -0.001, p.y + s * 1.25));
  ref *= gradCol * smoothstep(-0.5, 0.5, p.y);
  col = mix(ref, col, smoothstep(-0.005, 0.005, p.y));
  col *= smoothstep(0.125, 0.375, f);
  col *= smoothstep(0.875, 0.625, f);
  col = clamp(col, 0.0, 1.0);
  vec3 h = hash33(vec3(gl_FragCoord.xy, float(frame)));
  float dither = h.x * h.y;
  col += dither * 0.04;
  fragColor = vec4(col,1.0);
}


#version 300 es
// ╔═════════════╦════════════════╗
// ║ Marco Gomez ║ https://mgz.me ║
// ╚═════════════╩════════════════╝
precision highp float;

uniform sampler2D prgm1Texture;
uniform vec2 resolution;
uniform float time;
uniform int frame;

out vec4 fragColor;

vec3 hash33(vec3 p3) {
  p3 = fract(p3 * vec3(0.1031, 0.1030, 0.0973));
  p3 += dot(p3, p3.yxz + 19.19);
  return fract((p3.xxy + p3.yxx) * p3.zyx);
}

void main(void) {
  vec2 uv = gl_FragCoord.xy / resolution.xy;
  vec4 texCol = texture(prgm1Texture, uv);
  vec4 col = texCol;
  float w = 0.1;
  vec2 a = vec2(uv.x - 0.5, uv.y - 0.66);
  vec2 b = a * 0.15 / float(10.0);
  vec3 h = hash33(vec3(gl_FragCoord.xy, frame));
  uv += b * h.x;
  for (float i = 1.0; i > 0.9; i-= 0.000625) {
    uv -= 0.5;
    uv *= i;
    uv += 0.5;
    col += texture(prgm1Texture, uv) * w * 1.5;
    w *= 0.95;
  }
  col *= 0.9;
  fragColor = mix(texCol, col, 0.5);
}


#version 300 es
// ╔═════════════╦════════════════╗
// ║ Marco Gomez ║ https://mgz.me ║
// ╚═════════════╩════════════════╝
precision highp float;

uniform sampler2D prgm2Texture;
uniform vec2 resolution;
uniform float time;
uniform float fft;

out vec4 fragColor;

const float PI = acos(-1.0);
const float TAU = PI * 2.0;
const float hardscan = -16.0; // -8.0 = soft | -16.0 = medium
const float hardPix = -4.0; // -2.0 = soft | -4.0 = hard
const float maskDark = 0.5;
const float maskLight = 2.5;
const float hk = 1.0 / sqrt(3.0);

vec3 hueShift(vec3 col, float a) {
  const vec3 k = vec3(hk);
  float ca = cos(a);
  return vec3(col * ca + cross(k, col) * sin(a) + k * dot(k, col) * (1.0 - ca));
}

float toLinear(float c) {
  return (c <= 0.04045) ? c / 12.92 : pow(abs((c + 0.055) / 1.055), 2.4);
}

vec3 toLinear(vec3 c) {
  return vec3(toLinear(c.r), toLinear(c.g), toLinear(c.b));
}

float toSRGB(float c) {
  return(c < 0.0031308 ? c * 12.92 : 1.055 * pow(abs(c), 0.41666) - 0.055);
}

vec3 toSRGB(vec3 c) {
  return vec3(toSRGB(c.r), toSRGB(c.g), toSRGB(c.b));
}

vec3 fetch(vec2 pos, vec2 off, vec2 res) {
  pos = floor(pos * res + off) / res;
  if (max(abs(pos.x - 0.5), abs(pos.y - 0.5)) > 0.5) {
    return vec3(0.0);
  }
  vec3 fetch = texture(prgm2Texture, pos.xy, -16.0).xyz;
  fetch = hueShift(fetch, 2.0 * fft + time);
  return toLinear(mix(fetch, fetch * fetch, 0.5));
}

vec2 dist(vec2 pos, vec2 res) {
  pos = pos * res;
  return -((pos - floor(pos)) - vec2(0.5));
}

float gauss(float pos, float scale) {
  return exp2(scale * pos * pos);
}

vec3 horz3(vec2 pos, float off, vec2 res) {
  vec3 b = fetch(pos, vec2(-1.0, off), res);
  vec3 c = fetch(pos, vec2(+0.0, off), res);
  vec3 d = fetch(pos, vec2(+1.0, off), res);
  float dst = dist(pos, res).x;
  float scale = hardPix;
  float wb = gauss(dst - 1.0, scale);
  float wc = gauss(dst + 0.0, scale);
  float wd = gauss(dst + 1.0, scale);
  return (b * wb + c * wc + d * wd) / (wb + wc + wd);
}

vec3 horz5(vec2 pos, float off, vec2 res) {
  vec3 a = fetch(pos, vec2(-2.0, off), res);
  vec3 b = fetch(pos, vec2(-1.0, off), res);
  vec3 c = fetch(pos, vec2(+0.0, off), res);
  vec3 d = fetch(pos, vec2(+1.0, off), res);
  vec3 e = fetch(pos, vec2(+2.0, off), res);
  float dst = dist(pos, res).x;
  float scale = hardPix;
  float wa = gauss(dst - 2.0, scale);
  float wb = gauss(dst - 1.0, scale);
  float wc = gauss(dst + 0.0, scale);
  float wd = gauss(dst + 1.0, scale);
  float we = gauss(dst + 2.0, scale);
  return (a * wa + b * wb + c * wc + d * wd + e * we) / (wa + wb + wc + wd + we);
}

float scan(vec2 pos, float off, vec2 res) {
  float dst = dist(pos, res).y;
  return gauss(dst + off, hardscan);
}

vec3 tri(vec2 pos, vec2 res) {
  vec3 a = horz3(pos, -1.0, res);
  vec3 b = horz5(pos, +0.0, res);
  vec3 c = horz3(pos, +1.0, res);
  float wa = scan(pos, -1.0, res);
  float wb = scan(pos, +0.0, res);
  float wc = scan(pos, +1.0, res);
  return a * wa + b * wb + c * wc;
}

vec3 mask(vec2 pos) {
  pos.x += pos.y * 3.0;
  vec3 m = vec3(maskDark, maskDark, maskDark);
  pos.x = fract(pos.x / 6.0);
  if (pos.x < 0.333) {
    m.r = maskLight;
  } else if (pos.x < 0.666) {
    m.g = maskLight;
  } else {
    m.b = maskLight;
  }
  return m;
}

float bar(float pos, float bar) {
  pos -= bar;
  return pos * pos < 4.0 ? 0.0 : 1.0;
}

vec2 warp(vec2 uv, vec2 warpAmount) {
  uv = uv * 2.0 - 1.0;
  vec2 offset = abs(uv.yx) / vec2(warpAmount.x, warpAmount.y);
  uv = uv + uv * offset * offset;
  uv = uv * 0.5 + 0.5;
  return uv;
}

void drawVig(inout vec3 color, vec2 uv) {
  float vignette = uv.x * uv.y * (1.0 - uv.x) * (1.0 - uv.y);
  vignette = clamp(pow(abs(16.0 * vignette), 0.1), 0.0, 1.0);
  color *= vignette;
}

void main(void) {
  vec2 warpAmount = vec2(7.0, 5.0);
  vec2 res = vec2(resolution.x / 4.0, resolution.y / 3.0);
  vec2 uv = gl_FragCoord.xy / resolution.xy;
  float vig = (0.0 + 1.0 * 21.0 * uv.x * uv.y * (1.0 - uv.x) * (1.0 - uv.y));
  float v = exp(-0.01 * length(uv)) * vig;
  vec2 pos = mix(uv, warp(uv, warpAmount), 0.75);
  vec4 color = vec4(tri(pos, res) * mask(gl_FragCoord.xy), 1.0);
  color.xyz = toSRGB(color.xyz * 2.0);
  color = mix(color, color * v, 0.7);
  fragColor = vec4(color.xyz, 1.0);
}


#version 300 es
// ╔═════════════╦════════════════╗
// ║ Marco Gomez ║ https://mgz.me ║
// ╚═════════════╩════════════════╝
precision highp float;

#define duration 128.0

uniform vec2 resolution;
uniform float sampleRate;
uniform float blockOffset;

out vec2 fragColor;

const float PI = acos(-1.0);
const float TAU = PI * 2.0;
const float rootC2 = 65.417;
float notes[85];

void precomputeNotes(float rootNote) {
  for (int i = 0; i <= (12 * 7); i++) {
    notes[i] = rootNote * pow(abs(2.0), (float(i) / 12.0));
  }
}

float getNote(int noteIdx, int octave) {
  return notes[(noteIdx - 1) + ((octave - 1) * 12)];
}

float aLerp(float start, float end, float t, float A, float B) {
  return (
    (A * (end - t)) / (end - start) +
    (B * (t - start) / (end - start)));
}

float naiveADSR(float t, vec2 A, vec2 D, vec2 S, vec2 R) {
  vec2 start = vec2(0.0);
  float adsr = 0.0;
  if (t < A.x) {
    adsr = aLerp(start.x, A.x, t, start.y, A.y);
  } else if (t < D.x) {
    adsr = aLerp(A.x, D.x, t, A.y, D.y);
  } else if (t < S.x) {
    adsr = aLerp(D.x, S.x, t, D.y, S.y);
  } else if(t < R.x) {
    adsr = aLerp(S.x, R.x, t, S.y, R.y);
  } else {
    adsr = 0.0;
  }
  return adsr;
}

#define leftRight vec2(1.0, 1.0)
#define kickMaxFreq 130.81
#define scaleX 0.005
#define squareNum 10.0
#define L 0.5
#define basicA vec2(0.001, 1.0)
#define basicD vec2(0.4, 0.3)
#define basicS vec2(0.8, 0.3)
#define basicR vec2(1.5, 0.0)
#define snareA vec2(0.0002, 1.0)
#define snareD vec2(0.12, 0.09)
#define snareS vec2(0.3, 0.09)
#define snareR vec2(0.7, 0.0)
#define brushA vec2(0.01, 0.6)
#define brushD vec2(0.2, 0.1)
#define brushS vec2(0.22, 0.05)
#define brushR vec2(0.5, 0.0)
#define hatA vec2(0.001, 1.0)
#define hatD vec2(0.02, 0.5)
#define hatS vec2(0.02, 0.4)
#define hatR vec2(0.1, 0.0)
#define kNoiseA vec2(0.0002, 1.0)
#define kNoiseD vec2(0.03, 0.1)
#define kNoiseS vec2(0.05, 0.1)
#define kNoiseR vec2(0.06, 0.0)
#define kickA vec2(0.0002, 1.0)
#define kickD vec2(0.2, 0.0)
#define kickS vec2(0.22, 0.0)
#define kickR vec2(0.22, 0.0)
#define kickFA vec2(0.001, 1.0)
#define kickFD vec2(0.2, 0.0)
#define kickFS vec2(0.22, 0.0)
#define kickFR vec2(0.22, 0.0)
#define stabA vec2(0.0002, 1.0)
#define stabD vec2(0.2, 0.1)
#define stabS vec2(0.22, 0.1)
#define stabR vec2(0.92, 0.0)

vec2 stereoNoise(float t, float freq, vec2 lr) {
  float f = fract(sin(freq * t * 234.0) * 43153.0);
  float adsr = naiveADSR(t, kNoiseA, kNoiseD, kNoiseS, kNoiseR);
  return vec2(f * lr) * adsr;
}

vec2 stereoSin(float t, float freq, vec2 lr) {
  float adsr = naiveADSR(t, basicA, basicD, basicS, basicR);
  return vec2(sin(freq * t * TAU)) * lr * adsr;
}

vec2 stereoStab(float t, float freq, vec2 lr) {
  float adsr = naiveADSR(t, stabA, stabD, stabS, stabR);
  return vec2(sin(freq * t * TAU * 0.5)) * lr * adsr;
}

vec2 stereoKick(float t, float freq, vec2 lr) {
  float adsr = naiveADSR(t, kickA, kickD, kickS, kickR);
  float freq_adsr = naiveADSR(t, kickFA, kickFD, kickFS, kickFR);
  freq = (freq + freq_adsr * kickMaxFreq) * 0.6;
  return vec2(sin(freq * t * TAU)) * lr * adsr * 2.0;
}

vec2 stereoSnare(float t, float freq, vec2 lr) {
  float f = fract(sin(freq * t * 234.0) * 43153.0);
  float adsr = naiveADSR(t, snareA, snareD, snareS, snareR);
  return vec2(f * lr) * adsr * 2.0;
}

vec2 stereoBrush(float t, float freq, vec2 lr) {
  float f = fract(sin(freq * t * 234.0) * 43153.0);
  float adsr = naiveADSR(t, brushA, brushD, brushS, brushR);
  return vec2(f * lr) * adsr;
}

vec2 stereoHat(float t, float freq, vec2 lr) {
  float f = fract(sin(freq * t * 234.0) * 43153.0);
  float adsr = naiveADSR(t, hatA, hatD, hatS, hatR);
  return vec2(f * lr) * adsr;
}

vec2 stereoSaw(float t, float freq, vec2 lr) {
  return vec2(fract(freq * t / 2.0)) * lr;
}

vec2 stereoTri(float t, float freq, vec2 lr) {
  return vec2(abs(fract(freq * t) - 0.5) * 3.0);
}

vec2 stereoSquare(float t, float freq, vec2 lr) {
  float f = 0.0;
  for (float i = 1.0; i <= squareNum; i += 2.0) {
    f += sin((i * PI * freq * t * 0.5) / L) / i;
  }
  f *= (4.0 / PI);
  return f * lr;
}

vec2 beat1(float t) {
  vec2 f = stereoStab(t, getNote(1, 5), vec2(0.3, 0.9)); // C5
  f += stereoKick(t, getNote(1, 2), leftRight); // C2
  f += stereoTri(t, getNote(6, 2), leftRight); // F2
  return f;
}

vec2 beat2(float t) {
  vec2 f = stereoStab(t, getNote(4, 6), vec2(0.9, 0.5)); // Eb6
  f += stereoStab(t, getNote(8, 5), leftRight); // G5
  f += stereoKick(t, getNote(1, 2), leftRight) * 0.7; // C2
  return f;
}

vec2 beat3(float t) {
  vec2 f = stereoStab(t, getNote(11, 5), vec2(0.3, 0.9)); // Bb5
  f += stereoStab(t, getNote(8, 5), leftRight); // G5
  f += stereoTri(t, getNote(6, 2), leftRight); // F2
  return f;
}

vec2 beat4(float t) {
  vec2 f = stereoStab(t, getNote(9, 4), vec2(0.6, 0.8)); // Ab4
  f += stereoKick(t, getNote(1, 2), leftRight) * 0.5; // C2
  return f;
}

vec2 beat5(float t) {
  vec2 f = stereoStab(t, getNote(11, 5), vec2(0.5,0.9)); // Bb5
  f += stereoSnare(t, getNote(1, 2), leftRight) * 0.21; // C2
  return f;
}

vec2 beat6(float t) {
  return stereoStab(t, getNote(4, 5), vec2(0.6,0.7)); // Eb5
}

vec2 beat7(float t) {
  vec2 f = stereoStab(t, getNote(3, 4), vec2(0.9, 0.5)); // D4
  f += stereoTri(t, getNote(6, 2), leftRight); // F2
  return f;
}

vec2 beat8(float t) {
  vec2 f = stereoStab(t, getNote(6, 4), vec2(0.5, 0.9)); // F4
  f += stereoKick(t, getNote(1, 2), leftRight) * 0.5; // C2
  return f;
}

vec2 beat9(float t) {
  vec2 f = stereoStab(t, getNote(1, 4), vec2(0.6, 0.6)); // C4
  f += stereoBrush(t, getNote(1, 4) * 1.94, vec2(0.0, 0.4)); // C4ish
  f += stereoKick(t, getNote(1, 2), leftRight); // C2
  f += stereoTri(t, getNote(4, 2), leftRight); // Eb2
  return f;
}

vec2 beat10(float t) {
  vec2 f = stereoStab(t, getNote(11, 6), vec2(0.9, 0.5)) * 0.5; // Bb6
  f += stereoKick(t, getNote(1, 2), leftRight) * 0.7; // C2
  return f;
}

vec2 beat11(float t) {
  vec2 f = stereoStab(t, getNote(11, 4), vec2(0.2, 0.9)); // Bb4
  return f;
}

vec2 beat12(float t) {
  vec2 f = stereoStab(t, getNote(4, 4), vec2(0.9, 0.3)); // Eb4
  f += stereoKick(t, getNote(1, 2), leftRight) * 0.5; // C2
  return f;
}

vec2 beat13(float t) {
  vec2 f = stereoStab(t, getNote(1, 6), vec2(0.3, 0.9)); // C6
  f += stereoHat(t, getNote(1, 4) * 1.94,vec2(0.4, 0.0)); // C4ish
  f += stereoTri(t, getNote(3, 2), leftRight); // D2
  f += stereoSnare(t,getNote(1, 2), leftRight) * 0.21; // C2
  return f;
}

vec2 beat14(float t) {
  vec2 f = stereoStab(t, getNote(3, 5), vec2(0.9, 0.7)); // D5
  f += stereoHat(t, getNote(1, 4) * 1.94, vec2(0.4, 0.0)) * 0.9; // C4ish
  return f;
}

vec2 beat15(float t) {
  vec2 f = stereoStab(t, getNote(4, 5), vec2(0.5, 0.9)); // Eb5
  f += stereoHat(t, getNote(1, 4) * 1.94,vec2(0.4, 0.0)) * 0.8; // C4ish
  f += stereoTri(t, getNote(11, 2), leftRight); // Bb2
  return f;
}

vec2 beat16(float t) {
  vec2 f = stereoStab(t, getNote(11, 5), vec2(0.9, 0.7)); // Bb5
  f += stereoHat(t, getNote(1, 4) * 1.94, vec2(0.4, 0.0)) * 0.7; // C4ish
  f += stereoTri(t, getNote(4, 2) + fract(t) * 12.0 - 20.0, leftRight); // Eb2
  return f;
}

mat2 rot(float a) {
  return mat2(cos(a), -sin(a), sin(a), cos(a));
}

vec2 mainSound(float time) {
  float t = time;
  float speed = 0.25;
  float sequenceLength = 16.0;
  float len = sequenceLength * speed;
  float m = mod(t, len);
  float loopLength = (m < 0.5) ? 2.0 : 1.0;
  float sequencer = floor(mod(t, len) / speed + 1.0);
  time = (t < 16.0) ? mod(t, len) : mod(t, loopLength * speed);
  time = time * smoothstep(-0.01, 0.01, time);
  vec2 f;
       if (sequencer ==  1.0) f =  beat1(time);
  else if (sequencer ==  2.0) f =  beat2(time);
  else if (sequencer ==  3.0) f =  beat3(time);
  else if (sequencer ==  4.0) f =  beat4(time);
  else if (sequencer ==  5.0) f =  beat5(time);
  else if (sequencer ==  6.0) f =  beat6(time);
  else if (sequencer ==  7.0) f =  beat7(time);
  else if (sequencer ==  8.0) f =  beat8(time);
  else if (sequencer ==  9.0) f =  beat9(time);
  else if (sequencer == 10.0) f = beat10(time);
  else if (sequencer == 11.0) f = beat11(time);
  else if (sequencer == 12.0) f = beat12(time);
  else if (sequencer == 13.0) f = beat13(time);
  else if (sequencer == 14.0) f = beat14(time);
  else if (sequencer == 15.0) f = beat15(time);
  else if (sequencer == 16.0) f = beat16(time);
  if (t > 32.0 && t < 64.0 || t > 8.0 && t < 16.0) {
    f = mix((f * vec2(0.990, 1.001) * rot(m * 256.0)), f * 4.0, 0.5);
  } else {
    f = f * 2.0;
  }
  return f / 8.0;
}

void main(void) {
  precomputeNotes(rootC2);
  vec2 coord = floor(gl_FragCoord.xy);
  float time = blockOffset + (coord.x + coord.y * resolution.x) / sampleRate;
  fragColor = mainSound(time);
}