* BFS-along-adjacency circle brush (after PrusaSlicer's TriangleSelector). * * Starts at `seedTriIdx`, walks the mesh's neighbor graph, and invokes

* Estimate how many triangles subdivision will produce for a given edge length. * Uses a sample of existing edges to compute average edge length, the

* Validate, centre, and compute normals for a freshly parsed geometry. * Returns { nanCount, degenerateCount, originOffset }: removed-triangle counts

* Toggle displacement preview on/off. * When enabled: subdivides the current geometry to a moderate resolution, * computes smooth normals, and switc

* Snapshot the current paint mask (selection mode + excluded face indices into * the *base* geometry). Returns null when there's nothing meaningful t

* Apply a saved mask to the currently-loaded geometry. Filters out indices * that would be out-of-range for the loaded mesh (defensive — the .bumpmes

* Find a preset by name and activate it. By default, suppresses preset defaults * (resetTextureSmoothing + defaultScale override) so a just-restored

Paint a small preview canvas of the custom map and reveal the thumbnail row.

* Compute and set flat geometric face normals as a `faceNormal` attribute. * Unlike the `normal` attribute (which may be smooth/interpolated after *

* Determine the worst severity across fast + advanced diagnostics and apply it * to the popup container. 'error' > 'warn' > 'ok'.

* Builds per-non-indexed-vertex weights (1.0 = excluded from subdivision/displacement) * that combine the user-painted exclusion set AND the top/bott

* Compute a per-vertex `boundaryFalloffAttr` float attribute on the geometry. * Vertices near the boundary between masked and non-masked regions get

Compute the target max edge length from the brush diameter.

* Pre-compute the three edge lengths of every triangle in `geometry`. * Returned Float64Array has 3 entries per triangle (no winding semantics).

Return { w, h } capped at SIZE on the longest side, preserving aspect ratio.

Fractional part, always positive (mirrors GLSL fract)

Refresh (or initially build) the precision mesh from current brush size.