implement Default for vector and matrices

[rlane]

We're using maths-rs for vector types in http://oort.rs. It would be nice if these types could be used with derive(Default).

[polymonster]

Hi,

Thanks for this, hope you are finding the library useful and fun to use!

Happy to merge these changes, I was just wondering before doing so... should the default of a matrix be identity instead of just zeros?

Same goes for quaternion, if Vec and Matrix have a default then Quat should as well and it also has the same question regarding identity also applies. My feeling is that probably the default should be identity because it is a useful default where as all zeros in either quaternion or matrix are not very useful... Although I understand that the default is required to satisfy derive default and in those cases you would be probably initialising the matrix with useful values.

Once we have defaults for all the types then I can publish a new build to cargo, I can add the quaternion default myself once we decide but feel free to contribute if you want.

Thanks!

[rlane]

Yeah, identity is a better default for matrices. I pushed a commit to change that.

[polymonster]

Thanks, I will add the default quaternion and then publish to crates.