bigcurve: Adaptive Densification of Lines for Map Projections

Densify lines adaptively, as required by the curvature a map projection imposes on them. Edges are read as great circle arcs, and vertices are inserted along them only where the projected curve deviates from a straight chord by more than a tolerance measured on the map, following the adaptive resampling method of the 'd3-geo' 'JavaScript' library described in Bostock (2016) <https://github.com/d3/d3-geo>. Projections are computed with the 'PROJ' coordinate transformation library (<https://proj.org/>), so any coordinate reference system it supports can be a target. Inputs can be coordinate matrices, segment meshes or vertex pool topology from 'wkpool', and edges shared by neighbouring polygons receive identical new vertices.

Version: 0.6.0
Imports: stats
LinkingTo: cpp11
Suggests: geographiclib, knitr, maps, PROJ, rmarkdown, s2, testthat (≥ 3.0.0), textures, wk, wkpool (≥ 0.4.0)
Published: 2026-11-06
DOI: 10.32614/CRAN.package.bigcurve (may not be active yet)
Author: Michael D. Sumner [aut, cre, cph], Simon Wotherspoon [ctb] (developed the spherical track midpoint method that the great circle midpoint used here is based on), Mike Bostock [ctb, cph] (author of the 'd3-geo' adaptive resampling method ported here; see inst/COPYRIGHTS)
Maintainer: Michael D. Sumner <mdsumner at gmail.com>
BugReports: https://github.com/hypertidy/bigcurve/issues
License: MIT + file LICENSE
Copyright: see file COPYRIGHTS
URL: https://github.com/hypertidy/bigcurve, https://hypertidy.github.io/bigcurve/
NeedsCompilation: yes
SystemRequirements: PROJ (>= 8.0.0): libproj-dev (deb), proj-devel (rpm), proj (brew)
Materials: README, NEWS
CRAN checks: bigcurve results

Documentation:

Reference manual: bigcurve.html , bigcurve.pdf
Vignettes: bigcurve and s2: drawing the sphere on a flat map (source, R code)

Downloads:

Package source: bigcurve_0.6.0.tar.gz
Windows binaries: r-devel: not available, r-release: not available, r-oldrel: not available
macOS binaries: r-release (arm64): not available, r-oldrel (arm64): not available, r-release (x86_64): not available, r-oldrel (x86_64): not available

Linking:

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