How to know which value in a transform matrix stores what information?

[DasOhmoff San]

Hello,

I was searching for a very long time and could not find an answer.
And it does not seem to be easy to find.

When using transforms, there is this method:

const float* sf::Transform::getMatrix() const

It returns a 4x4 matrix of all the transform information, so far everything is clear.
But how do I know which entry in the matrix stands for which information?

For example, out of those 16 values, which one stands for the x position and which for the y position?
Or the x scale and y scale?

Is there some kind of documentation for that?

[Nexus]

First, a transform matrix is generally describing a mapping from one 2D vector onto another. This doesn't need to be translation, rotation or scale only -- it can involve other transformations, such as skewing. This implies that it's not always possible to extract position, rotation and scale exactly.

Second, I would suggest to search for such keywords in general, as it's a recurring topic in graphics programming and mathematics, not something SFML-specific. A good start might be here:

https://math.stackexchange.com/q/237369
https://en.wikipedia.org/wiki/Transformation_matrix#Examples_in_2D_computer_graphics