extractBoundaryEigenModes
Extracts the count lowest-frequency eigenmodes of this rectified contour's outline, ignoring its interior entirely -- the boundary-only counterpart to Shape.extractEigenModes. resolution parameters equidistant in rectified (arc-length) space are treated as a cycle graph, and its graph-Laplacian eigenvectors extracted; see org.openrndr.extra.math.eigenmodes.extractCycleEigenModes. A RectifiedContour is required rather than a plain ShapeContour specifically so that equal steps in t are equal steps in arc length -- true by construction here, since ts[i] = i / resolution in rectified space -- which is what the cycle graph's uniform edge weights assume.
As with EigenModeBoundaryCondition.NEUMANN, the underlying Laplacian is only positive semi-definite: mode 0 is always the trivial, patternless zero-eigenvalue constant mode.
Return
The requested modes, ascending by BoundaryEigenMode.eigenvalue.
Parameters
Number of modes to extract, ordered from lowest to highest frequency (including the trivial constant mode).
Number of points sampled equidistantly (by arc length) around the contour.
Source of the eigensolver's random initial vectors. Defaults to a fixed seed (Random(0)) for reproducible results.