trippy-browse/shell.html at master · hdresearch/trippy-browse · GitHub

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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style>
  * { margin: 0; padding: 0; box-sizing: border-box; }
  html, body { width: 1280px; height: 900px; overflow: hidden; background: #000; }
  #c { width: 1280px; height: 900px; display: block; }
  #viewport {
    width: 1280px; height: 900px;
    overflow: hidden; position: relative;
    background: #fff;
  }
  #scroller {
    width: 1280px; position: absolute; top: 0; left: 0;
  }
</style>
</head>
<body>

<canvas id="c" width="1280" height="900" layoutsubtree>
  <div id="viewport">
    <div id="scroller"></div>
  </div>
</canvas>

<script>
var W = 1280, H = 900;
var canvas = document.getElementById('c');
var viewport = document.getElementById('viewport');
var scroller = document.getElementById('scroller');
var ctx = canvas.getContext('2d');
var t0 = performance.now();
var scrollY = 0;
var paintOk = false;

// Lava lamp blobs — wide orbits, 2x speed, mixed warm + accent colors
var blobs = [
  // warm core blobs
  { cx: 0.5, cy: 0.5, r: 190, sx: 0.14, sy: 0.10, ox: 0.4, oy: 0.4, hBase: 15,  hRange: 12, phase: 0.0 },
  { cx: 0.5, cy: 0.5, r: 160, sx: 0.18, sy: 0.12, ox: 0.35, oy: 0.38, hBase: 35, hRange: 10, phase: 1.1 },
  { cx: 0.5, cy: 0.5, r: 210, sx: 0.10, sy: 0.16, ox: 0.38, oy: 0.35, hBase: 350, hRange: 15, phase: 2.3 },
  { cx: 0.5, cy: 0.5, r: 170, sx: 0.16, sy: 0.08, ox: 0.42, oy: 0.42, hBase: 25,  hRange: 18, phase: 3.7 },
  { cx: 0.5, cy: 0.5, r: 145, sx: 0.12, sy: 0.18, ox: 0.36, oy: 0.36, hBase: 5,   hRange: 14, phase: 4.9 },
  { cx: 0.5, cy: 0.5, r: 180, sx: 0.20, sy: 0.14, ox: 0.4, oy: 0.38, hBase: 40,  hRange: 10, phase: 5.8 },
  { cx: 0.5, cy: 0.5, r: 135, sx: 0.14, sy: 0.20, ox: 0.35, oy: 0.4, hBase: 355, hRange: 12, phase: 0.7 },
  // new accent blobs — violet, teal
  { cx: 0.5, cy: 0.5, r: 150, sx: 0.15, sy: 0.11, ox: 0.38, oy: 0.4, hBase: 280, hRange: 15, phase: 1.9 },
  { cx: 0.5, cy: 0.5, r: 140, sx: 0.11, sy: 0.17, ox: 0.4, oy: 0.36, hBase: 175, hRange: 12, phase: 4.2 },
];

var lastPaintTime = 0;
var avgFrameMs = 33;

canvas.onpaint = function() {
  var now = performance.now();
  var dt = now - lastPaintTime;
  lastPaintTime = now;
  if (dt > 0 && dt < 500) avgFrameMs = avgFrameMs * 0.85 + dt * 0.15;
  var slow = avgFrameMs > 66; // below ~15fps

  var t = (now - t0) / 1000.0;
  ctx.clearRect(0, 0, W, H);

  // === Single drawElementImage: breathing page ===
  ctx.save();
  var breath = 1.0 + Math.sin(t * 0.7) * 0.02;
  ctx.translate(W/2, H/2);
  ctx.scale(breath, breath);
  ctx.translate(-W/2, -H/2);
  try {
    ctx.drawElementImage(viewport, 0, 0, W, H);
    paintOk = true;
  } catch(e) { paintOk = false; }
  ctx.restore();

  // === Glitch: copy horizontal strips (skip when fps drops below 15) ===
  if (!slow) {
    var sliceH = 60;
    for (var sy = 0; sy < H; sy += sliceH * 2) {
      var shift = Math.sin(sy * 0.03 + t * 2.5) * 4 + Math.sin(sy * 0.09 + t * 7) * 1.5;
      if (Math.abs(shift) > 0.5) {
        ctx.drawImage(canvas, 0, sy, W, sliceH, shift, sy, W, sliceH);
      }
    }
  }

  // === Lava lamp blobs — warm colored circles drifting over the page ===
  for (var i = 0; i < blobs.length; i++) {
    var b = blobs[i];
    var bx = b.cx * W + Math.sin(t * b.sx + b.phase) * W * b.ox;
    var by = b.cy * H + Math.cos(t * b.sy + b.phase * 1.3) * H * b.oy;
    var br = b.r + Math.sin(t * 0.25 + b.phase) * 40;
    var bh = b.hBase + Math.sin(t * 0.2 + i) * b.hRange;

    ctx.save();
    ctx.globalCompositeOperation = 'multiply';
    ctx.globalAlpha = 0.22 + Math.sin(t * 0.4 + i * 0.9) * 0.04;
    var g = ctx.createRadialGradient(bx, by, 0, bx, by, br);
    g.addColorStop(0, 'hsla(' + bh + ', 85%, 55%, 1)');
    g.addColorStop(0.6, 'hsla(' + bh + ', 75%, 60%, 0.5)');
    g.addColorStop(1, 'hsla(' + bh + ', 70%, 65%, 0)');
    ctx.fillStyle = g;
    ctx.beginPath();
    ctx.arc(bx, by, br, 0, Math.PI * 2);
    ctx.fill();
    ctx.restore();
  }

  canvas.requestPaint();
};

canvas.requestPaint();

// Track full scroll height before we start hiding things
var fullScrollHeight = 0;

window.shellScroll = function(dy) {
  scrollY = Math.max(0, scrollY + dy);
  var maxScroll = Math.max(0, fullScrollHeight - H);
  scrollY = Math.min(scrollY, maxScroll);
  scroller.style.top = (-scrollY) + 'px';
  cullOffscreen();
};

// Collect all leaf-ish block elements that we can individually cull
var cullableEls = [];

function collectCullable(root) {
  var children = root.children;
  for (var i = 0; i < children.length; i++) {
    var el = children[i];
    var tag = el.tagName;
    if (tag === 'STYLE' || tag === 'LINK' || tag === 'SCRIPT') continue;
    // If this element is tall (>2x viewport) and has children, recurse into it
    if (el.offsetHeight > H * 2 && el.children.length > 0) {
      collectCullable(el);
    } else if (el.offsetHeight > 0) {
      cullableEls.push(el);
    }
  }
}

function measureChildren() {
  cullableEls = [];
  collectCullable(scroller);
  for (var i = 0; i < cullableEls.length; i++) {
    var el = cullableEls[i];
    // Walk offsetParent chain to get absolute top within scroller
    var ot = 0;
    var p = el;
    while (p && p !== scroller) { ot += p.offsetTop; p = p.offsetParent; }
    el._origTop = ot;
    el._origBot = el._origTop + el.offsetHeight;
  }
  fullScrollHeight = scroller.scrollHeight;
  cullOffscreen();
}

// Override cullOffscreen to use cullableEls
function cullOffscreen() {
  var margin = H;
  var viewTop = scrollY - margin;
  var viewBot = scrollY + H + margin;
  for (var i = 0; i < cullableEls.length; i++) {
    var el = cullableEls[i];
    var top = el._origTop;
    var bot = el._origBot;
    if (top === undefined) continue;
    if (bot < viewTop || top > viewBot) {
      if (!el._culled) {
        el._culled = true;
        // visibility:hidden keeps layout but skips painting
        // DO NOT use content-visibility:hidden — it breaks drawElementImage on parent
        el.style.visibility = 'hidden';
      }
    } else {
      if (el._culled) {
        el._culled = false;
        el.style.visibility = '';
      }
    }
  }
}

window.shellNavigate = function(html) {
  scroller.innerHTML = '';
  scrollY = 0;
  scroller.style.top = '0px';
  scroller.className = '';
  scroller.removeAttribute('style');
  scroller.style.cssText = 'width:1280px;position:absolute;top:0;left:0';

  var parser = new DOMParser();
  var doc = parser.parseFromString(html, 'text/html');

  var styles = doc.querySelectorAll('style, link[rel="stylesheet"]');
  styles.forEach(function(s) { scroller.appendChild(document.adoptNode(s)); });

  if (doc.body) {
    if (doc.body.getAttribute('style'))
      scroller.style.cssText += ';' + doc.body.getAttribute('style');
    if (doc.body.className)
      scroller.className = doc.body.className;
    while (doc.body.firstChild)
      scroller.appendChild(document.adoptNode(doc.body.firstChild));
  }

  // Measure positions after a frame so layout is done
  setTimeout(measureChildren, 100);
  return { title: doc.title || '', children: scroller.children.length, height: scroller.scrollHeight };
};

window.shellGetTitle = function() { return ''; };
window.shellReady = true;
</script>
</body>
</html>