title: Am I able to initiate blank variables and declare them afterwards?
body: <p>I would like to do something like this:</p>
  
  <pre><code>vec4 text;
  if (something){
    text = texture(backgroundTexture, pass_textureCoords);
  }
  if (somethingElse){
    text = texture(anotherTexture, pass_textureCoords);
  }
  </code></pre>
  
  <p>Is this valid GLSL code, and if not, is there any suitable alternative?</p>