Add Voronoi methods #1487
Add Voronoi methods #1487
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Some example output. I haven't written a benchmark, but single-core perf on my M2 is around 5.5 seconds to produce a clipped Voronoi diagram from 2693630 input vertices. That drops to around 1.3 seconds (including the snapping step) if you use a tolerance of |
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| // - `CoordsIter` trait for vertex iteration | ||
| // The `line_intersection` and `Euclidean::distance` functions from geo are already used here. | ||
| // | ||
| // TODO: Cell clipping currently uses BooleanOps intersection. Alternative approaches that |
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These are possible TODOs for follow-up work; I'm fairly happy with the existing clipping mechanisms, which took a long time to get into their current state. I suspect they could be further simplified if we could clip LineString geometries using BooleanOps, but I don't want to hold this up while we think through that.
| Ok(raw_cells | ||
| .into_iter() | ||
| .flat_map(|cell| { | ||
| // Skip intersection if cell is entirely within clip bounds |
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This gets us a 40-45 % speedup (inspired by JTS: https://github.com/locationtech/jts/blob/7b79342eb04dc572a02b6520c7c2d2e58b54ae86/modules/core/src/main/java/org/locationtech/jts/triangulate/VoronoiDiagramBuilder.java#L184)
Adds the Voronoi trait with methods to compute Voronoi diagrams: - voronoi_edges(): Returns line segments from unconstrained Delaunay triangulation - voronoi_edges_with_params(): Same with configurable tolerance and clipping - voronoi_cells(): Returns Vec<Polygon<T>> with cells clipped to padded bounding box - voronoi_cells_with_params(): Same with configurable tolerance and clipping Configuration is via VoronoiParams builder: - .tolerance(T): Snap nearby points before triangulation - .clip(VoronoiClip): Control clipping behaviour - Padded: 50% padding around input bbox (default, matches PostGIS) - Envelope: Clip to exact input bounding box - Polygon(&Polygon<T>): Clip to custom boundary Cells are constructed by iterating over Spade's voronoi_faces() and converting vertices (circumcenters for inner, bounding box intersections for outer) into polygon rings. Signed-off-by: Stephan Hügel <[email protected]>
Adds the Voronoi trait with methods to compute Voronoi diagrams:
Configuration is via VoronoiParams builder:
Cells are constructed by iterating over Spade's voronoi_faces() and converting vertices (circumcenters for inner, bounding box intersections for outer) into polygon rings.
CHANGES.mdif knowledge of this change could be valuable to users.Depends on #1486, please review / merge that first.