getpercentage is a function. In c, 0 is false, else true.
so if (getpercentage( parameters to a function that does who knows what))
is true, do the rest of it.
[] is index into an array or anything treated as an array. The parameters to getpercentage contain arrays.
++ means add 1, assuming the operator is a standard type like int.
0x01 is hex for 1. Its a way to have to type more stuff for no good reason.
info() // some other function that does who knows what.
else,
loop 17 times (whatever 17 means here)
conditionally setting values to 0 or 255 (hex again)
Without more context, that is about as much as I can do without making tons of assumptions like assuming info prints some stuff to the screen and that getpercentage calculates some sort of percent.