Add missing cols/rows constants

[JesseTG]

Should I add anything like rows or cols to the vector type traits? Because they can be treated as either column vectors or row vectors, so I dunno...

[regnirpsj]

i vote yes, then #441 can be unified (instead of separate handling for vector and matrix).

[JesseTG]

But as row vectors or column vectors?

[regnirpsj]

iirc, they should be column vectors by default, i.e. vec4 is a mat1x4.

[JesseTG]

Actually, the spec says that it depends on whether the vector is the left or right operand in a vector/matrix multiplication. Nowhere does it otherwise refer to the notion of a row vector or column vector.

[regnirpsj]

that is correct in a general sense but given p' = P * V * M * p would be the usual way in opengl to transform a point, vectors would be assumed to be column oriented; this could/should be documented. the alternative is to just stick with the type<>::columns and not assign col/row dimensions for non-matrices.

[JesseTG]

Let's see what @Groovounet has to say.

[JesseTG]

...so what do you have to say, @Groovounet? I'm fine with the metaprogramming stuff being moved to a separate file, but until this PR is merged in I can't pull in the latest GLM changes (because I need this fix for my project).

[JesseTG]

Notice me, senpai~

[JesseTG]

@Groovounet Can you take a look at this bugfix, please?

[JesseTG]

@Groovounet Hi. Do you like this change set?

[Groovounet]

I made a branch today type_trait where I investigated. Somehow there are build errors with Visual Studio.

[JesseTG]

Seriously? Christ. I'll take a look over the weekend.

[Groovounet]

For your information, it was already broken before your changes. I came up with a workaround (in the branch) but I don't know whether it is good.

[JesseTG]

All right, thank you for taking a look at this pull request.