Old animated movie where a prince marries the daughter of a giant

This movie shouldn't be this hard to find, but the internet just isn't giving it up. It's truly maddening.

This is an animated movie using traditional hand-drawn animation, I believe that I watched it back in 1993. The movie starts with a baby being found naked in the woods, and that baby would be adopted as a prince.

The prince grows up and falls in love with a woman, I don't remember the circumstances of that meeting. I do however remember that the woman explains that they can't be married until her father, a giant, says that it's okay.

The prince takes a small band of men with him and meets the giant. The giant laughs at the idea of giving his daughter away for marriage, but is willing to explain the conditions of such a union. The prince must get blood from a specific witch, because her blood will work as shaving cream. The prince must get, I believe, a giant fish bone because it will work as a razor. Basically; the giant won't give his daughter up for marriage unless he can attend with a groomed appearance.

The prince finds the objects he needs, and after they groom the giant, the giant desperately wants to see a mirror. The giant is taken back -- in a good way -- by the change to his appearance and happily gives his blessing for the marriage.

This was a rare movie for me in that the giant wasn't evil, and in the end he made good on his promise. This wasn't a cliché story where the hero kills the giant. Please, please help me with this one.

I found. It's "Culhwch and Olwen".