// lazy hack for css

document.body.innerHTML = `

  <style> 

    button { 

      cursor: pointer; 

    }

    .red { 

      background-color: red; 

    } 

  </style>

`

const btn = document.body.appendChild(

  Object.assign(

    document.createElement('button'), 

    { innerText: 'click me' }

  )

)

btn.addEventListener('click', e => {

  e.target.classList.toggle('red')

})

const deltaTransformPoint = (matrix, point) => {

  return {

    x: point.x * matrix.a + point.y * matrix.c,

    y: point.x * matrix.b + point.y * matrix.d

  }

}

const decomposeMatrix = matrix => {

  let px = deltaTransformPoint(matrix, { x: 0, y: 1 })

  let py = deltaTransformPoint(matrix, { x: 1, y: 0 })

  let skewX = FROM_RADS * Math.atan2(px.y, px.x) - 90

  let skewY = FROM_RADS * Math.atan2(py.y, py.x)

  return {

    tx: matrix.e,

    ty: matrix.f,

    scaleX: Math.sqrt(matrix.a * matrix.a + matrix.b * matrix.b),

    scaleY: Math.sqrt(matrix.c * matrix.c + matrix.d * matrix.d),

    skewX: skewX,

    skewY: skewY,

    rotation: skewX

  }

}

with (self) with (Math){ typeof self

with (window) with (sin) if (true) self }

if (window . i) {

  if (window . you) {

    if (window . we) {

      with (window . blue) {

        for ( window . what in window . how ) {

          for ( window . how in window . who ) {

            do {} while (true)

          }

        }

      }

    }

  }

}

//------------------------------------------------------------------

float function_IterativeSquareRoot (float x) {

  // http://en.wikipedia.org/wiki/Methods_of_computing_square_roots

  // Ancient Babylonian technology

  functionName = "Iterative (Heron's) Square Root";

  float y = 0.5; 

  int n = 6;

  for (int i=0; i<n; i++) {

    y = (y + x/y)/2.0;

  }

  return y;

}