getShaderByName(name) {
    let shader = this.getFromArr(name, extraTransitions);
    if (!shader) shader = this.getFromArr(name, transitions);
    if (!shader && name.toLowerCase() == 'random') shader = this.getRandomShader();
    if (!shader) shader = this.getFromArr('fade', transitions);

    return shader;
  }
Get the shader source code by name
@param {string} name - shader name
@return {string} shader source
@public