Crate polystrata 

polystrata

High-performance, topologically robust 2D polygon clipping, Boolean operations, and self-intersection healing kernel based on a 2D Stratified Tolerance Complex.

• Zero dependencies, native f64 coordinates (no integer grid quantization).
• 4-Stage Snapped Consolidation Pipeline:
  1. Scale-aware vertex tolerance disks (r₀ = 1e-9 × L) & union-find merging.
  2. Iterative vertex-on-edge T-junction splitting, interior crossing splits, and coincident edge consolidation.
  3. Planar half-edge spoke sorting (CCW) and closed face-cycle extraction.
  4. Left-normal winding evaluation + O(C + E) dual-graph BFS classification and pinch-vertex decomposition.

Quick Start

use polystrata::{union, intersect, difference, xor, heal, KernelOptions};

let square_a = [[0.0, 0.0], [10.0, 0.0], [10.0, 10.0], [0.0, 10.0]];
let square_b = [[5.0, 5.0], [15.0, 5.0], [15.0, 15.0], [5.0, 15.0]];

let opts = KernelOptions::default();

let u = union(&square_a, &square_b, opts);
assert!((u.total_area - 175.0).abs() < 1e-6);

let i = intersect(&square_a, &square_b, opts);
assert!((i.total_area - 25.0).abs() < 1e-6);

let d = difference(&square_a, &square_b, opts);
assert!((d.total_area - 75.0).abs() < 1e-6);

let x = xor(&square_a, &square_b, opts);
assert!((x.total_area - 150.0).abs() < 1e-6);

Modules

arena

consolidate

grid

topology

Structs

KernelOptions

Configuration options for the 2D Stratified Tolerance Complex kernel.

KernelResult

Output produced by a 2D Boolean or healing operation.

Point2D

A 2D point in double-precision (f64) world coordinates.

PolygonWithHoles2D

A 2D polygon consisting of one counter-clockwise (CCW) outer shell and zero or more clockwise (CW) interior holes.

PolystrataKernel

Reusable 2D Boolean & topological healing kernel owning its own pre-allocated KernelArena.

Segment2D

A directed 2D line segment tagged with an optional body_index.

Enums

BooleanOp

Standard 2-body Boolean operation selector.

WindingRule

Winding rule used to classify the interior of each input body from its signed winding number w:

Traits

ShapeInput

Trait implemented by all supported 2D shape inputs ([Point2D], [[f64; 2]], [(f64, f64)], PolygonWithHoles2D, slices/vectors of loops or polygons, and [Segment2D]).

Functions

boolean_multi

Execute a general N-body Boolean operation defined by a custom predicate predicate(&[w₀, w₁, …]) -> bool over the per-body winding vector of each planar face cycle.

clip

Execute a 2-body Boolean operation and return GeoJSON-style MultiPolygon coordinate rings (Vec<Vec<Vec<[f64; 2]>>>), where each ring is explicitly closed (first == last).

difference

Compute the Boolean difference (A \ B) of two 2D shapes.

heal

Topological self-intersection healing & polygonization of a single 2D shape or segment soup.

intersect

Compute the Boolean intersection (A ∩ B) of two 2D shapes.

intersect_all

Single-pass N-body Boolean intersection (B₀ ∩ B₁ ∩ … ∩ Bₙ₋₁) across an arbitrary slice of shapes.

signed_loop_area

Compute the signed area of a closed 2D loop via the Shoelace formula.

union

Compute the Boolean union (A ∪ B) of two 2D shapes.

union_all

Single-pass N-body Boolean union (B₀ ∪ B₁ ∪ … ∪ Bₙ₋₁) across an arbitrary slice of shapes.

wasm_alloc_raw_segments

Allocate / resize the raw input segment buffer (seg_count * 5 f64s: [x0, y0, x1, y1, bodyIndex]) and return a pointer in WASM linear memory where JS can write the segments directly.

wasm_compute_cycles_and_windings

Run Stages 0–3 plus Stage 4a winding evaluation for custom N-body predicates (booleanMulti) and interactive pipeline inspection (inspectPipeline). Returns cycle_count.

wasm_execute_prepared

Execute Stages 1–4 on the already-prepared normalized segments in arena. Returns the number of output boundary loops written into out_loop_meta and out_coords.

wasm_execute_raw

Full end-to-end execution (Stages 0–4) from raw_segments. Returns the number of output boundary loops.

wasm_extract_from_cycle_keep

Run Stage 4b loop extraction from arena.cycle_keep[0..cycle_count] (populated by JS). Returns the number of output boundary loops.

wasm_get_cycle_count

wasm_get_cycle_keep_ptr

wasm_get_cycle_sample_x_ptr

wasm_get_cycle_sample_y_ptr

wasm_get_cycle_windings_f64_ptr

wasm_get_e_alive_ptr

wasm_get_e_delta_w_ptr

wasm_get_edge_count

wasm_get_ev0_ptr

wasm_get_ev1_ptr

wasm_get_out_coords_len

wasm_get_out_coords_ptr

wasm_get_out_loop_meta_ptr

wasm_get_out_total_area

wasm_get_prep_body_count

wasm_get_prep_cx

wasm_get_prep_cy

wasm_get_prep_diagonal

wasm_get_prep_r0

wasm_get_prep_rmax

wasm_get_v_alive_ptr

wasm_get_vertex_count

wasm_get_vr_ptr

wasm_get_vx_ptr

wasm_get_vy_ptr

wasm_prepare_segments

Stage 0 preparation: normalize the seg_count segments already written into raw_segments. Used by benchmark harnesses to pre-normalize segments before timed execution.

xor

Compute the Boolean symmetric difference (A ⊕ B) of two 2D shapes.

Type Aliases

Loop2D

A closed 2D polygonal ring represented as an ordered list of vertices (the closing edge from last to first is implicit).