Yes, thats the common way for C functions that do something more object oriented. Gamestudio has the very same convention.

Underscore or camel case is just a matter of what one likes more, I for one prefer camel case but everyone should use whatever they like more.
Its the same with syntax styles, some people like K&R more, I like the Allman style more and some people even prefer the GNU style. As long as the code is consistent, there is nothing wrong with the styles.