Curve tracing for SSI

## File Description + `src` includes all SSI tracing test samples. ## Build + type these commands to build all samples: ``` mkdir build && cd build cmake .. make ``` ## Dependencies + this project uses `FetchContent` of CMake to get dependencies from [libigl](https://github.com/libigl/libigl), including `libigl`, `eigen3`, `glfw` and so on. So please **check your network** before building the project.