I have been learning opengl lately, and I am following two tutorials. One of them is http://www.opengl-tutorial.org and the other one is http://ogldev.atspace.co.uk . The first one is relatively simpler, and uses external libraries such as glm ( which is the main topic of my question ), however other one tries to implement everything itself, every vector, matrix, almost everything except glut. The second one which implements everything, is great at theory, and actually thought me how opengl works, so I gained some trust on it. However, it really doesnt make sense to me to even implement matrixes. GLM looks like it works just fine, and I would prefer to use glm::lookAt, instead of trying to implement every detail of camera movement myself ( although it teaches well ). So I do not know how to go forward with it. Should I use glm or try to implement all myself ?
Note: I should add that my aim is to build a simple game engine
Building your own math library for computer graphics is a great way to fully teach yourself all the required concepts. However, GLM finished this job for you and also made their implementations quite efficient.
So, unless you don't like their design philosophy you'd likely want to to use GLM for your engine, there is no disadvantage.
Also, their license is quite forgiving: http://glm.g-truc.net/copying.txt