Those overhead clear panels are assuredly not the standard single thickness window glass. If glass is used in an application like this it is going to have to be a tempered glass. Thickness required would be dependent upon the width and length if each panel. I would not be surprised to find glass being close to 3/8" if not even 1/2" thick.
Glass panels like that are extremely heavy and the framing structure to hold it in place will be substantial.
If you do some research you may find that the pictured patio cover is not glass at all but instead made up of clear acrylic panels. This would be much lower weight and be in line with the type of framing structure showing in your picture. Do an image search on Google with "clear acrylic patio roof" and you will see many examples that look a lot like the picture that you show.