ctx.js

// the base module

module.exports = function(canvas){
  if('string' == typeof canvas) canvas = dcoument.getElementById(canvas)
  touchdown.start(canvas)
  var ctx = window.ctx = canvas.getContext('2d')
  var pen = basic(ctx)
  ctx.translate(0.5, 0.5)
  ctx.lineWidth = 10
  ctx.globalCompositeOperation = 'destination-over';
  ctx.strokeStyle = 'rgba(50, 205, 33, .31)'
  canvas.addEventListener('touchdown', function(e){pen.down(e.detail)})
  canvas.addEventListener('deltavector', function(e){pen.move(e.detail)})
  canvas.addEventListener('liftoff', function(e){pen.up(e.detail)})
}

// the pen module

var trig = require('../trig')

module.exports = function(ctx, denit){

  var lasti, d = 0;

  return {
    down: touchdown,
    move: deltavector,
    up: liftoff
  }

  function touchdown(evt){
    ctx.beginPath()
    ctx.moveTo(evt.x, evt.y)
    last = [evt.x, evt.y]
  }

  function deltavector(evt){
      ctx.lineTo(evt.x, evt.y)
      ctx.stroke()
  }

  function liftoff(evt){
  }
}