Generate a preview from a given resource with the specified size. This must always be implemented.
Returning an empty texture is an OK way to fail and let another generator take care.
Care must be taken because this function is always called from a thread (not the main thread).
Generate a preview from a given resource with the specified size. This must always be implemented. Returning an empty texture is an OK way to fail and let another generator take care. Care must be taken because this function is always called from a thread (not the main thread).