pan><span> = </span><span class="identifier">fract</span><span>(</span><span class="identifier">p</span><span>)
        </span><span class="keyword">val</span><span> </span><span class="identifier">u</span><span>: </span><span class="identifier">vec2</span><span> = </span><span class="identifier">f</span><span> * </span><span class="identifier">f</span><span> * (</span><span class="number-literal">3.0f</span><span> - </span><span class="number-literal">2.0f</span><span> * </span><span class="identifier">f</