title: error C3861: 'roundf': identifier not found
body: <p>I'm normally good at googling stuff like this but I can't seem to find anything this time.</p>
  
  <p>I downloaded some source code from <a href="https://en.wikibooks.org/wiki/OpenGL_Programming/Scientific_OpenGL_Tutorial_04">here</a> and it uses a function called <code>roundf</code>.</p>
  
  <p>I already have <code>#include &lt;math.h&gt;</code> and as a first thought added <code>#include &lt;cmath&gt;</code> but still have the problem. I can't seem to find out where the function originates...</p>
  
  <p>Is there an alternative function? Or does anyone know where it comes from so I can include the header file?</p>