What is direct and indirect characterization of Gatsby in The Great Gatsby? (with quotes and analysis)

Direct characterization is what is explicitly told to us
by the author about a character.  However, in The Great Gatsby, the
story is told through a first person observer viewpoint.  In other words, Gatsby is
characterized directly by Nick, not the author.  The opening pages of the novel provide
examples of Nick's direct characterization of Gatsby in which Nick declares that Gatsby
had

an
extraordinary gift for hope, a romantic readiness such as I have never found in any
other person and which it is not likely I shall ever find
again.

Indirect
characterization is achieved by inference.  From the descriptions of the character's
actions, speech, appearance, home, we can determine much about a character's personality
that usually results in our judgment of that particular personality.  Throughout
The Great Gatsby, the readers must determine whether or not Nick's
comments about Gatsby are true or if we have a different impression of the man that Nick
is both impressed with and somewhat contemptuous of.

For
instance, Gatsby's constant use of "old sport," seems to imply a somewhat pretentious
speech.  His  car is described as

readability="8">

rich cream color, bright with nickel, swollen
here and there in its monstrous length with triumphant hatboxes and supper-boxes and
tool-boxes

giving the
impression of ostentatiousness.  Gatsby's association with a man like Mr. Wolfshiem
suggests Gatsby's corruption.  Even when Nick withholds his judgment, which he often
does until the end of the novel, we are given key details that allow us to develop our
own opinion of this character.