pixel-blast.js

/* pixel-blast.js — motion-anything recipe · ambient · faithful GPU shader (dependency-free WebGL via _fx/shaderbg.js). */
(function(g){ 'use strict';
  var FRAG='#version 300 es\nprecision highp float;\nprecision highp float;\n\nuniform vec3  uColor;\nuniform vec2  uResolution;\nuniform float uTime;\nuniform float uPixelSize;\nuniform float uScale;\nuniform float uDensity;\nuniform float uPixelJitter;\nuniform int   uEnableRipples;\nuniform float uRippleSpeed;\nuniform float uRippleThickness;\nuniform float uRippleIntensity;\nuniform float uEdgeFade;\n\nuniform int   uShapeType;\nconst int SHAPE_SQUARE   = 0;\nconst int SHAPE_CIRCLE   = 1;\nconst int SHAPE_TRIANGLE = 2;\nconst int SHAPE_DIAMOND  = 3;\n\nconst int   MAX_CLICKS = 10;\n\nuniform vec2  uClickPos  [MAX_CLICKS];\nuniform float uClickTimes[MAX_CLICKS];\n\nout vec4 fragColor;\n\nfloat Bayer2(vec2 a) {\n  a = floor(a);\n  return fract(a.x / 2. + a.y * a.y * .75);\n}\n#define Bayer4(a) (Bayer2(.5*(a))*0.25 + Bayer2(a))\n#define Bayer8(a) (Bayer4(.5*(a))*0.25 + Bayer2(a))\n\n#define FBM_OCTAVES     5\n#define FBM_LACUNARITY  1.25\n#define FBM_GAIN        1.0\n\nfloat hash11(float n){ return fract(sin(n)*43758.5453); }\n\nfloat vnoise(vec3 p){\n  vec3 ip = floor(p);\n  vec3 fp = fract(p);\n  float n000 = hash11(dot(ip + vec3(0.0,0.0,0.0), vec3(1.0,57.0,113.0)));\n  float n100 = hash11(dot(ip + vec3(1.0,0.0,0.0), vec3(1.0,57.0,113.0)));\n  float n010 = hash11(dot(ip + vec3(0.0,1.0,0.0), vec3(1.0,57.0,113.0)));\n  float n110 = hash11(dot(ip + vec3(1.0,1.0,0.0), vec3(1.0,57.0,113.0)));\n  float n001 = hash11(dot(ip + vec3(0.0,0.0,1.0), vec3(1.0,57.0,113.0)));\n  float n101 = hash11(dot(ip + vec3(1.0,0.0,1.0), vec3(1.0,57.0,113.0)));\n  float n011 = hash11(dot(ip + vec3(0.0,1.0,1.0), vec3(1.0,57.0,113.0)));\n  float n111 = hash11(dot(ip + vec3(1.0,1.0,1.0), vec3(1.0,57.0,113.0)));\n  vec3 w = fp*fp*fp*(fp*(fp*6.0-15.0)+10.0);\n  float x00 = mix(n000, n100, w.x);\n  float x10 = mix(n010, n110, w.x);\n  float x01 = mix(n001, n101, w.x);\n  float x11 = mix(n011, n111, w.x);\n  float y0  = mix(x00, x10, w.y);\n  float y1  = mix(x01, x11, w.y);\n  return mix(y0, y1, w.z) * 2.0 - 1.0;\n}\n\nfloat fbm2(vec2 uv, float t){\n  vec3 p = vec3(uv * uScale, t);\n  float amp = 1.0;\n  float freq = 1.0;\n  float sum = 1.0;\n  for (int i = 0; i < FBM_OCTAVES; ++i){\n    sum  += amp * vnoise(p * freq);\n    freq *= FBM_LACUNARITY;\n    amp  *= FBM_GAIN;\n  }\n  return sum * 0.5 + 0.5;\n}\n\nfloat maskCircle(vec2 p, float cov){\n  float r = sqrt(cov) * .25;\n  float d = length(p - 0.5) - r;\n  float aa = 0.5 * fwidth(d);\n  return cov * (1.0 - smoothstep(-aa, aa, d * 2.0));\n}\n\nfloat maskTriangle(vec2 p, vec2 id, float cov){\n  bool flip = mod(id.x + id.y, 2.0) > 0.5;\n  if (flip) p.x = 1.0 - p.x;\n  float r = sqrt(cov);\n  float d  = p.y - r*(1.0 - p.x);\n  float aa = fwidth(d);\n  return cov * clamp(0.5 - d/aa, 0.0, 1.0);\n}\n\nfloat maskDiamond(vec2 p, float cov){\n  float r = sqrt(cov) * 0.564;\n  return step(abs(p.x - 0.49) + abs(p.y - 0.49), r);\n}\n\nvoid main(){\n  float pixelSize = uPixelSize;\n  vec2 fragCoord = gl_FragCoord.xy - uResolution * .5;\n  float aspectRatio = uResolution.x / uResolution.y;\n\n  vec2 pixelId = floor(fragCoord / pixelSize);\n  vec2 pixelUV = fract(fragCoord / pixelSize);\n\n  float cellPixelSize = 8.0 * pixelSize;\n  vec2 cellId = floor(fragCoord / cellPixelSize);\n  vec2 cellCoord = cellId * cellPixelSize;\n  vec2 uv = cellCoord / uResolution * vec2(aspectRatio, 1.0);\n\n  float base = fbm2(uv, uTime * 0.05);\n  base = base * 0.5 - 0.65;\n\n  float feed = base + (uDensity - 0.5) * 0.3;\n\n  float speed     = uRippleSpeed;\n  float thickness = uRippleThickness;\n  const float dampT     = 1.0;\n  const float dampR     = 10.0;\n\n  if (uEnableRipples == 1) {\n    for (int i = 0; i < MAX_CLICKS; ++i){\n      vec2 pos = uClickPos[i];\n      if (pos.x < 0.0) continue;\n      float cellPixelSize = 8.0 * pixelSize;\n      vec2 cuv = (((pos - uResolution * .5 - cellPixelSize * .5) / (uResolution))) * vec2(aspectRatio, 1.0);\n      float t = max(uTime - uClickTimes[i], 0.0);\n      float r = distance(uv, cuv);\n      float waveR = speed * t;\n      float ring  = exp(-pow((r - waveR) / thickness, 2.0));\n      float atten = exp(-dampT * t) * exp(-dampR * r);\n      feed = max(feed, ring * atten * uRippleIntensity);\n    }\n  }\n\n  float bayer = Bayer8(fragCoord / uPixelSize) - 0.5;\n  float bw = step(0.5, feed + bayer);\n\n  float h = fract(sin(dot(floor(fragCoord / uPixelSize), vec2(127.1, 311.7))) * 43758.5453);\n  float jitterScale = 1.0 + (h - 0.5) * uPixelJitter;\n  float coverage = bw * jitterScale;\n  float M;\n  if      (uShapeType == SHAPE_CIRCLE)   M = maskCircle (pixelUV, coverage);\n  else if (uShapeType == SHAPE_TRIANGLE) M = maskTriangle(pixelUV, pixelId, coverage);\n  else if (uShapeType == SHAPE_DIAMOND)  M = maskDiamond(pixelUV, coverage);\n  else                                   M = coverage;\n\n  if (uEdgeFade > 0.0) {\n    vec2 norm = gl_FragCoord.xy / uResolution;\n    float edge = min(min(norm.x, norm.y), min(1.0 - norm.x, 1.0 - norm.y));\n    float fade = smoothstep(0.0, uEdgeFade, edge);\n    M *= fade;\n  }\n\n  vec3 color = uColor;\n\n  // sRGB gamma correction - convert linear to sRGB for accurate color output\n  vec3 srgbColor = mix(\n    color * 12.92,\n    1.055 * pow(color, vec3(1.0 / 2.4)) - 0.055,\n    step(0.0031308, color)\n  );\n\n  fragColor = vec4(srgbColor * M, M);\n}\n';
  function init(){ var els=document.querySelectorAll('.pixel-blast'); for(var i=0;i<els.length;i++){ if(els[i].__sbg) continue;
    var h=g.ShaderBG(els[i], FRAG, {"timeScale":0.5,"uniforms":{"uColor":{"t":"3f","v":[0.7058823529411765,0.592156862745098,0.8117647058823529]},"uShapeType":{"t":"1i","v":0},"uPixelSize":{"t":"1f","v":3},"uScale":{"t":"1f","v":2},"uDensity":{"t":"1f","v":1},"uPixelJitter":{"t":"1f","v":0},"uEnableRipples":{"t":"1i","v":1},"uRippleSpeed":{"t":"1f","v":0.3},"uRippleThickness":{"t":"1f","v":0.1},"uRippleIntensity":{"t":"1f","v":1},"uEdgeFade":{"t":"1f","v":0.5},"uClickPos":{"t":"2fv","v":[-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1]},"uClickTimes":{"t":"1fv","v":[0,0,0,0,0,0,0,0,0,0]}}});
    if(h){ (function(){ var N=10, pos=new Array(2*N), times=new Array(N), ix=0, k;
      for(k=0;k<N;k++){ pos[2*k]=-1; pos[2*k+1]=-1; times[k]=0; }
      h.el.addEventListener('pointerdown', function(e){ var r=h.el.getBoundingClientRect();
        var sx=h.canvas.width/r.width, sy=h.canvas.height/r.height;
        pos[2*ix]=(e.clientX-r.left)*sx; pos[2*ix+1]=(r.height-(e.clientY-r.top))*sy;
        times[ix]=h.time(); ix=(ix+1)%N;
        h.set('uClickPos',{t:'2fv',v:pos}); h.set('uClickTimes',{t:'1fv',v:times}); }); })(); } } }
  if(document.readyState!=='loading') init(); else document.addEventListener('DOMContentLoaded', init);
})(window);