What is the Freetype policy and/or goals with regard to integer overflows? How practical are the large sizes that push outline dimensions beyond 16 bits, or pixel size of 1024? In a few places I see 64-bit arithmetic utilized to control the overflow by means of FT_Int64. This integer type is not even documented. When is it ok to use this type? For example, when I calculate a dot product of 2 vectors, which is a very basic task. If dimensions are limited to 16-bits, the dot product would fit into 32 bits, so there is no need to worry about the overflow here.