* Replace Matrix<> with Vector<> where vectors are explicitly intended.
I found these via `rg "Eigen::Matrix<double, \w+, 1>"`.
* Pass all Eigen matrices by const reference. I found these via `rg
"\(Eigen"` on main (the initializer list constructors make more false
positives).
* Replace MakeMatrix() and operator<< usage with initializer list
constructors. I found these via `rg MakeMatrix` and `rg "<<"`
respectively.
* Deprecate MakeMatrix()
In the second constructor, a new LinearSystem is created and set to
m_plant. This takes a const ref though, so it's storing a reference to a
temporary object. After the constructor finishes, m_plant points to an
invalid object. When Update() is called, it will crash with a
segmentation fault.
This patch fixes the use-after-free by making m_plant a LinearSystem
value type. The first constructor will generate a copy, but that only
happens once.
This includes physics simulation support for arms/elevator models, as well as differential drivetrains.
Swerve might be added at a later date.
Co-authored-by: Claudius Tewari <cttewari@gmail.com>
Co-authored-by: Prateek Machiraju <prateek.machiraju@gmail.com>
Co-authored-by: Tyler Veness <calcmogul@gmail.com>
