git ssb

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var Cardinal = require('cardinal-spline-js')
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function midpointY (a, b, y) {
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  if(y < a[1] || y > b[1]) throw new Error('out of bounds in y axis')
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  var _y = b[1] - a[1]
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  var m = _y/(y-a[1])
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  return [a[0] + (b[0]-a[0])/m, y]
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}
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function midpointX (a, b, x) {
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  if(x < a[0] || x > b[0]) throw new Error('out of bounds in x axis')
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  var _x = b[0] - a[0]
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  var m = _x/(y-a[0])
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  return [x, a[1] + (b[1]-a[1])/m]
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}
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exports.midpointX = midpointX
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exports.midpointY = midpointY
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function snap (points, size, dimension) {
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  dimension = 1
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  var output = [], max = points[0][dimension]
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  for(var i = 1; i < points.length; i ++)
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    while(max <= points[i][dimension]) {
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      output.push(midpointY(points[i-1], points[i], max))
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      max += size
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    }
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  return output
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}
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exports.snapY = snap
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function smooth2D (points, tension, sides) {
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  tension = tension || 0.5
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  sides = sides || 5
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  var p = Cardinal.getCurvePoints(points.reduce(function (a, b) {
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      return a.concat(b)
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    }), tension, sides)
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  var o = []
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  for(var i = 0; i < p.length; i+=2)
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    o.push([p[i],p[i+1]])
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  return o
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}
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var m = require('./midpoint')
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function smooth (points, step, tension) {
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  step = step || 1
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  var smoothX = m.snapY(smooth2D(points.map(function (e) {
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    return [e[0],e[1]]
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  }), tension, 10), step)
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  var smoothZ = m.snapY(smooth2D(points.map(function (e) {
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    return [e[2],e[1]]
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  }), tension, 10), step)
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  return smoothX.map(function (e, i) {
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    return [e[0],e[1], smoothZ[i][0]]
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  })
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}
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exports.smooth = smooth
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