Hamlet claims that his feelings are what they "seem" . how does hamlet feel about his father , king hamlet ?

Hamlet claims that he is actually sad about his father's passing. He accuses others in the room, including his mother, of merely pretending to be sad.

“Seems,” madam? Nay, it is. I know not “seems.”
'Tis not alone my inky cloak, good mother,
Nor customary suits of solemn black,
Nor windy suspiration of forced breath,
No, nor the fruitful river in the eye,
Nor the dejected 'havior of the visage,
Together with all forms, moods, shapes of grief,
That can denote me truly. These indeed “seem,”
For they are actions that a man might play.
But I have that within which passeth show,
These but the trappings and the suits of woe.