Module snap_rounding 

Hobby snap rounding for robust geometric operations.

Snap rounding is a technique to achieve robustness in computational geometry by snapping all coordinates (and intersection points) to a regular grid. This eliminates floating-point inconsistencies and ensures topological validity of noded segment arrangements.

Algorithm

The iterative Hobby snap rounding algorithm proceeds as:

1. Snap all input coordinates to the precision grid.
2. Collect all pairwise segment-segment intersections (cross-line).
3. Snap each intersection to the grid.
4. Split every segment that an intersection point lies on.
5. Repeat steps 2-4 until convergence or max_iterations is reached.
6. Remove zero-length segments.

References

• J. Hobby, “Practical segment intersection with finite precision output”, Computational Geometry, 13(4):199-214, 1999.

Structs

SnapRoundingOptions

Options controlling snap rounding behaviour.

SnapRoundingResult

Result returned by snap_round.

SnappedSegment

A single output segment after snap rounding.

Functions

snap_coordinate

Snap a single coordinate to the precision grid.

snap_linestring

Snap all coordinates in a slice to the precision grid, removing consecutive duplicates that arise after snapping.

snap_round

Perform iterative Hobby snap rounding on a collection of polylines.