Swizzling (computer graphics)

In computer graphics, swizzling is the ability to compose vectors by arbitrarily rearranging and combining components of other vectors.[1] For example, if A = {1,2,3,4}, where the components are x, y, z, and w respectively, you could compute B = A.wwxy, whereupon B would equal {4,4,1,2}. Additionally, combining two two-component vectors can create a four-component vector, or any combination of vectors and swizzling. This is common in GPGPU applications.

In terms of linear algebra, this is equivalent to multiplying by a matrix whose rows are standard basis vectors. If ${\displaystyle A=(1,2,3,4)^{T}}$, then swizzling ${\displaystyle A}$ as above looks like

${\displaystyle A.wwxy={\begin{bmatrix}0&0&0&1\\0&0&0&1\\1&0&0&0\\0&1&0&0\end{bmatrix}}{\begin{bmatrix}1\\2\\3\\4\end{bmatrix}}={\begin{bmatrix}4\\4\\1\\2\end{bmatrix}}}$