GLM quaternion

[LangFox]

At first, I have to say that GLM is must-have for OpenGL developers.

But the quaternion could be optimized. It should be more efficient to make an axis-angle format and have a function to rotate vector.

Finally, great work! Yet it can be better! 

[Groove]

You have very welcome!

It actually depend how you use it. If you need to go back to the proper quaternion form, you lose a lot of benefice. If you really want to use a axis angle form, I think it would be better to simply use a vec3 and a scalar.

Have you some samples where you find advantages of axis-angle?

[LangFox]

Well, it is nothing important, just a little laziness, hehe.

My original math is:

Code: [Select]

sm_quat q(axis, theta);
vec3 result = q.rotate(v);

Now using GLM instead:

Code: [Select]

quat p(1.0, v.x, v.y, v.z);
quat q(cos(theta/2), axis.x*sin(theta/2), axis.y*sin(theta/2), axis.z*sin(theta/2));
quat result = cross(cross(q, p), conjugate(q));

Anyway, that doesn't matter.