Due to my ignorance, I created my lovely font for unicode characters using BitFontCreator. I planned to use it for text outputted on WinApi. After long period of production, I discovered that it can only export .c, .bin, and .bmp file. But these are not font file usable for WinApi, I am forced to use PutPixel function, but it is too slow to output! What am I supposed to do? I come up with one solution: change .c or .bmp to .ttf, but how ?(Is there other way?) Thanks.
You generally can't, bitfontcreator is a bitmap font maker, which is really just a bitmap drawing that has nothing to do with "Fonts" until you load the image into a program that can slice it up into meaningful "letter 'W' is found at x/y/w/h values: ....".
OpenType fonts on the other hand (of which TTF is one of the two internal flavours) is a vector outline real font format (in that it has an authoritative and exhaustive specification), and is pretty much one of the most complex pieces of software in existence =)
What you can do is import each letter into a program that can do vector abstraction when importing a bitmap for a letter, like HighLogic's FontCreator, so you end up with vector approximations of your bitmaps. You'll then spend a fair amount of time fixing the abstraction mistakes, but at least you'll have an actual modern font after that.