Translation

Translation is stored as a three-dimensional vector inside a 4 X 4 matrix. The translation component of the matrix describes how much to move an object on each axis. Because we decided to use Row Major matrices, translation is stored in elements 41, 42, and 43 of the matrix:

Getting Ready

We're going to implement three functions: one to retrieve the translation already stored inside a 4 X 4 matrix, one to return a translation matrix given x, y, and z components, and one to return a translation matrix given the same x, y, and z components packed inside a vec3. When building any type of matrix, we start with the identity matrix and modify elements. We do this because the identity matrix has no effect on multiplication. The unused elements of a translation matrix should not affect rotation or scale; therefore we leave the first three rows the same as the identity matrix.

How to do it…

Follow these steps to set and retrieve the translation of a matrix:

1. Add the declaration...