Specifies the number of KERNINGPAIR structures pointed to by lpkrnpair. The function will not copy more kerning pairs than specified by nPairs.
Points to an array of KERNINGPAIR structures that receive the kerning pairs when the function returns. This array must contain at least as many structures as specified by nPairs. If this parameter is NULL, the function returns the total number of kerning pairs for the font.
Specifies the number of kerning pairs retrieved or the total number of kerning pairs in the font, if the function is successful. Zero is returned if the function fails or there are no kerning pairs for the font.