sings</span>
<span class="Keyword">var</span> <span class="Identifier">currentTime</span> <span class="Operator">=</span> <span class="DecNumber">0</span>
<span class="Keyword">let</span> <span class="Identifier">duration</span> <span class="Operator">=</span> <span class="DecNumber">100</span>
<span class="Keyword">let</span> <span class="Identifier">startPositionX</span><span class="Punctuation">:</span> <span class="Identifier">float32</span> <span class="Operator">=</span> <span class="FloatNumber">0.0<