what if gun powder never made it to the west?

[Nor]

i don't know if this is ASB, but what if the secrets to gun powder never left china, how would european weapon/technology development change?

I speculate that it would by more along a flame thrower line seeing how the byzantine already bad something along that line. i don't know if this would make it a double what if, but what if the formula on how to make greek fire spread throughout europe instead of dying with constantinople?