/// <summary>
/// Retrieves the value of an import parameter for the specified <see cref="Resource"/>.
/// If the parameter was undefined, it will be (persistently) initialized with the specified default value.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="env"></param>
/// <param name="resource">A reference to the <see cref="Duality.Resource"/> that is parameterized.</param>
/// <param name="parameterName">The name of the parameter.</param>
/// <param name="defaultValue">If the value wasn't defined for the given Resource, the default value will be used instead.</param>
/// <returns>The retrieved value, or the default value that was specified.</returns>
public static T GetOrInitParameter <T>(this IAssetImportEnvironment env, IContentRef resource, string parameterName, T defaultValue)
{
T value;
if (env.GetParameter <T>(resource, parameterName, out value))
{
return(value);
}
env.SetParameter <T>(resource, parameterName, defaultValue);
return(defaultValue);
}