Consider floating point precision consequences

[jannikmi]

Work out where floating point precision issues could occur and if they have impact on the correctness of the algorithms. Make changes if necessary.

cf. https://karlobermeyer.github.io/VisiLibity1/

[jannikmi]

Can input normalisation help?

[jannikmi]

The numerical stability (linalg solve) should be investigated. probably linked to #64

[jannikmi]

use integers instead of floats for a higher accuracy for the angle representations (fixed value range: 0.0 - 4.0)