Integrating shingles

I am going to build a cedar covered patio where the metal one is currently . How would I integrate the new shingles on my patio cover to the old ones that are currently on the roof. I will be tying in the patio cover from both sides. How will I seam together the shingles that do not run parallel to the others?

I have a picture but it is not allowing me to post a link in my post for some reason…

You can’t upload pics due to the forums anti-spam settings, but you can paste the link as
www . mypic . com / myhouse.pic

Are you tying cedar shakes into asphalt shingles at 2 valleys? IF so just use the open cut valley method installing metal in the valleys first.