/span>.height

    div = radius + radius + <span class="number">1</span>
    w4 = width &lt;&lt; <span class="number">2</span>
    widthMinus1 = width - <span class="number">1</span>
    heightMinus1 = height - <span class="number">1</span>
    radiusPlus1 = radius + <span class="number">1</span>
    sumFactor = radiusPlus1 * (radiusPlus1 + <span class="number">1</span>) / <span class="number">2</span>

    stackStart = <span class="keyword">new</span> BlurStack()
    stack = stackStart
    
    <span class