index.html

## readme.md

      
          Raw
        
        
              readme.md
            
          
    More mouseover aliasing.

rasterizeText from Andrew Mollica. Canvas is super fast!

  
## index.html
<!DOCTYPE html>
<meta charset='utf-8'>
<body style='background: #fff;'>
  <canvas width='960' height='300'></canvas>
</body>
<script src='//d3js.org/d3.v4.min.js'></script>
<script>

var width = 960,
    height = 300,
    s = 2,
    w = Math.floor(960/s),
    h = Math.floor(300/s)


var points = d3.range(w*h).map(function(i){
  return {x: i % w, y: i/w >> 0, i: i}
})

points.forEach(function(d, i){
  d.px = d.x*s
  d.py = d.y*s

  d.l = d.x ? points[i - 1] : d
  d.t = d.y ? points[i - w] : d
})

var canvas = d3.select('canvas').node()
var ctx = canvas.getContext('2d')


setPointsOn(points)


var mPos = {px: 0, py: 0}
d3.select('body')
    .on('mousemove', function(){
      mPos = {px: d3.mouse(this)[0], py: d3.mouse(this)[1]} })
    .on('click', function(){
      if (Math.random() < .5){
        onPoints.forEach(function(d){ d.y = h - d.y })
      } else{
        onPoints.forEach(function(d){ d.x = w - d.x })
      }
    })


var onPoints = points.filter(function(d){ return d.on })
d3.timer(function(t){
  ctx.clearRect(0, 0, width, height);
  ctx.fillStyle = '#000'
  ctx.fillRect(0, 0, width, height);

  ctx.beginPath()
  onPoints.forEach(function(d, i){
    var dx = (Math.random() - .5)*1
    var dy = (Math.random() - .5)*1

    if (isWithin(d, mPos, 50)){

      dx += mPos.px - d.px
      dy += mPos.py - d.py

      dx *= -1/5
      dy *= -1/5

      if (Math.random() < .4){
        d.px = d.x*s
        d.py = d.y*s
        dx = 0
        dy = 0
      }

    }

    else if (Math.random() < .3){
      dx = xor(dx < 0, d.x*s - d.px < 0) ? -dx : dx
      dy = xor(dy < 0, d.y*s - d.py < 0) ? -dy : dy
      dx /= 1/5
      dy /= 1/5
      // d.px = d.x*s
      // d.py = d.y*s
      // dx = 0
      // dy = 0
    }

    d.px += dx
    d.py += dy

    if (d.l.on && isWithin(d, d.l, 50)){
      ctx.moveTo(d.px,    d.py)
      ctx.lineTo(d.l.px,  d.l.py)
    }
    if (d.t.on && isWithin(d, d.t, 50)){
      ctx.moveTo(d.px,    d.py)
      ctx.lineTo(d.t.px,  d.t.py)
    }
  })
  ctx.strokeStyle = 'rgba(0,255,0,.2)'
  ctx.lineWidth = 1
  ctx.stroke()


})

function setPointsOn(points) {
  ctx.font = '600 300px sans-serif'
  ctx.textAlign = 'center';
  ctx.textBaseline = 'middle';
  ctx.fillText('words', width/2, height/2);

  var imageData = ctx.getImageData(0, 0, width, height).data

  points.forEach(function(d){
    d.on = imageData[(d.py*width + d.px)*4 + 3]
  })
}

function xor(a, b){ return (a || b) && !(a && b) }

function isWithin(a, b, dist){
  return Math.abs(a.px - b.px) + Math.abs(a.py - b.py) < dist
}

d3.select(self.frameElement).style('height', h*s + 'px');
</script>