gistfile1.js

function renderPage( options, page ) {

    var canvas = options.__canvas,
      ctx = canvas.getContext( "2d" ),
      viewport = page.getViewport( 1, 0 ),
      wActual = options.__wrapperDiv.clientWidth,
      hActual = options.__wrapperDiv.clientHeight,
      wRatio,
      hRatio,
      ratio;

    renderComplete = false;

    canvas.height = hActual;
    canvas.width = wActual;

    hRatio = canvas.height / viewport.height;
    wRatio = canvas.width / viewport.width;

    ratio = Math.min( hRatio, wRatio );

    canvas.height = viewport.height;
    canvas.width = viewport.width;


    page.render({
      canvasContext: ctx,
      viewport: viewport
    });

    options.__rendered = true;
    ctx.scale( wRatio, hRatio );

    canvas.height = hActual;
    canvas.width = wActual;
  }